1
6A Digital-DC Synchronous Step-Down DC/DC Converter
ZL2106
The ZL2106 is a digital power conversion and management IC
that combines an integrated synchronous step-down DC/DC
converter with key power management functions in a small
package, resulting in a flexible and integrated solution.
The ZL2106 can provide an output voltage from 0.54V to 5.5V
(with margin) from an input voltage between 4.5V and 14V.
Internal low rDS(ON) synchronous power MOSFETs enable the
ZL2106 to deliver continuous loads up to 6A with high
efficiency. An internal Schottky bootstrap diode reduces
discrete component count. The ZL2106 also supports phase
spreading to reduce system input capacitance.
Power management features such as digital soft-start delay
and ramp, sequencing, tracking, and margining can be
configured by simple pin-strapping or through an on-chip serial
port. The ZL2106 uses the PMBus™ protocol for
communication with a host controller and the Digital-DC bus
for interoperability between other Zilker Labs devices.
Features
• Integrated MOSFET switches
• 6A continuous output current
• ±1% output voltage accuracy
•Snapshot™ parametric capture
•I
2C/SMBus interface, PMBus compatible
• Internal non-volatile memory (NVM)
Applications
• Telecom, Networking, Storage equipment
• Test and Measurement equipment
• Industrial control equipment
• 5V and 12V distributed power systems
Related Literature
•AN1468 “ZL2106EVAL1Z Evaluation Board”, USB Adapter
Board, GUI Software
•AN2010 “Thermal and Layout Guidelines for Digital-DC™
Products”
•AN2033 “Zilker Labs PMBus Command Set-DDC
ProductsPMBus Command Set”
•AN2035 “Compensation Using CompZL™”
FIGURE 1. ZL2106 EFFICIENCY
40
50
60
70
80
90
100
IOUT (A)
EFFICIENCY (%)
VOUT = 3.3V
0.0 1.0 2.0 3.0 4.0 5.0 6.0
VIN = 12V
fSW = 200kHz
L = 6µH
May 31, 2011
FN6852.5
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774 |Copyright Intersil Americas Inc. 2009, 2010, 2011. All Rights Reserved
Intersil (and design) is a trademark owned by Intersil Corporation or one of its subsidiaries.
All other trademarks mentioned are the property of their respective owners.
ZL2106
2FN6852.5
Typical Application Circuit
The following application circuit represents a typical
implementation of the ZL2106. For PMBus operation, it is
recommended to tie the enable pin (EN) to SGND.
Block Diagram
VOUT
3.3V
VIN
12V
I2C/
SMBus††
DDC Bus
†
ENABLE
C
B
47nF
C
25
10µF
C
DD
2.2µF
C
OUT
150µF
L
OUT
2.2µH
C
IN
100 µF
VSET
SA
SCL
SDA
SALRT
FC
PG
SYNC
DGND
ZL2106
SW
SW
SW
SW
SW
PGND
VDDP
SW
BST
VRA
VR
VDDS
VDDP
VDDP
EN
V2P5
MGN
VSEN
SGND
PGND
PGND
PG ND
PGND
CFG
VTRK
SS
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
27
26
25
24
23
22
21
20
19
36
35
34
33
32
31
30
29
28
ePAD
(SGND)
PGOOD
C
RA
4.7 µF
C
R
4.7µF
DDC
F.B.
‡
Notes:
‡
Ferrite bead is optional for input noise suppression.
†
The DDC bus pull-up resistance will vary based on the capacitive loading of the bus, including the number of devices
connected. The 10 kΩ default value, assuming a maximum of 100 pF per device, provides the necessary 1 µs pull-up rise
time. Please refer to the Digital-DC Bus section for more details.
††
The I
2
C/SMBus pull -up resistance will vary based on the capacitive loading of the bus, including the number of devices
connected. Please refer to the I
2
C/SMBus specifications for more details.
FIGURE 2. 12V TO 3.3V/6A APPLICATION CIRCUIT (5ms SS DELAY, 5ms SS RAMP)
2.5V
LDO
PWM
Control
&
Drivers
SDA
SCL
SAL RT
VRA
V2 P5
VDDS
BST
VSEN
VDDP
VSET
VTRK
SS
PG
EN
CFG
SW
PGND
7V
LDO
SMBus
SA
NVM
SYNC
Power
Mgmt
DDC Bus
DDC
V
OUT
MGN
V
IN
5V
LDO
VR
FIGURE 3. BLOCK DIAGRAM
ZL2106
3FN6852.5
Pin Configuration
ZL2106
(36 LD QFN)
TOP VIEW
VSET
SA
SCL
SDA
SALRT
FC
PG
SYNC
DGND
ZL2106
SW
SW
SW
SW
SW
PGND
VDDP
SW
BST
VRA
VR
VDDS
VDDP
VDDP
EN
V2P5
MGN
VSEN
SGND
PGND
PGND
PGND
PGND
CFG
VTRK
SS
Exposed Paddle
Connect to SGND
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
27
26
25
24
23
22
21
20
19
36
35
34
33
32
31
30
29
28
DDC
FIGURE 4.
Pin Descriptions
PIN LABEL
TYPE
(Note 1) DESCRIPTION
1 PG O Power-good. This pin transitions high 100ms after output voltage stabilizes within regulation band.
Selectable open drain or push-pull output. Factory default is open drain.
2 DGND PWR Digital ground. Common return for digital signals. Connect to low impedance ground plane.
3SYNCI/O, M
(Note 2)
Clock synchronization pin. Used to set switching frequency of internal clock or for synchronization to
external frequency reference.
4 VSET I, M Output voltage select pin. Used to set VOUT set-point and VOUT max.
5 SA I, M Serial address select pin. Used to assign unique SMBus address to each IC.
6 SCL I/O Serial clock. Connect to external host interface.
7 SDA I/O Serial data. Connect to external host interface.
8 SALRT O Serial alert. Connect to external host interface if desired.
9 FC I, M Loop compensation select pin. Used to set loop compensation.
10 CFG I, M Configuration pin. Used to control the SYNC pin, sequencing and enable tracking.
11 SS I, M Soft-start pin. Used to set the ramp delay and ramp time, sets UVLO and configure tracking.
12 VTRK I Track sense pin. Used to track an external voltage source.
13 VSEN I Output voltage positive feedback sensing pin.
14 SGND PWR Common return for analog signals. Connect to low impedance ground plane.
15, 16, 17,
18, 19
PGND PWR Power ground. Common return for internal switching MOSFETs. Connect to low impedance ground plane.
20, 21, 22,
23, 24, 25
SW I/O Switching node (level-shift common).
26 BST PWR Bootstrap voltage for level-shift driver (referenced to SW).
27, 28, 29 VDDP PWR Bias supply voltage for internal switching MOSFETs (return is PGND).
30 VDDS PWR IC supply voltage (return is SGND).
ZL2106
4FN6852.5
31 VR PWR Regulated bias from internal 7V low-dropout regulator (return is PGND). Decouple with a 4.7µF capacitor to
PGND.
32 VRA PWR Regulated bias from internal 5V low-dropout regulator for internal analog circuitry (return is SGND).
Decouple with a 4.7µF capacitor to SGND.
33 V2P5 PWR Regulated bias from internal 2.5V low-dropout regulator for internal digital circuitry (return is DGND).
Decouple with a 10µF capacitor.
34 DDC I/O Digital-DC Bus (open drain). Interoperability between Zilker Labs devices.
35 MGN I Margin pin. Used to enable margining of the output voltage.
36 EN I Enable pin. Used to enable the device (active high).
ePad SGND PWR Exposed thermal pad. Common return for analog signals. Connect to low impedance ground plane.
NOTES:
1. I = Input, O = Output, PWR = Power or Ground, M = Multi-mode pins. Please refer to Section “Multi-mode Pins” on page 11.
2. The SYNC pin can be used as a logic pin, a clock input or a clock output.
Pin Descriptions (Continued)
PIN LABEL
TYPE
(Note 1) DESCRIPTION
Ordering Information
PART NUMBER
(Note 4) PART MARKING
TEMP RANGE
(°C) PACKAGE
PKG.
DWG. #
ZL2106ALCN (Note 2) 2106 -40 to +85 36 Ld 6mmx6mm QFN L36.6x6A
ZL2106ALCNT (Notes 1, 2) 2106 -40 to +85 36 Ld 6mmx6mm QFN L36.6x6A
ZL2106ALCNTK (Notes 1, 2) 2106 -40 to +85 36 Ld 6mmx6mm QFN L36.6x6A
ZL2106ALCF (Note 3) 2106 -40 to +85 36 Ld 6mmx6mm QFN L36.6x6C
ZL2106ALCFT (Notes 1, 3) 2106 -40 to +85 36 Ld 6mmx6mm QFN L36.6x6C
ZL2106ALCFTK (Notes 1, 3) 2106 -40 to +85 36 Ld 6mmx6mm QFN L36.6x6C
ZL2106ALCF-01 (Note 3) 2106-01 -40 to +85 36 Ld 6mmx6mm QFN L36.6x6C
ZL2106ALCFT-01 (Notes 1, 3) 2106-01 -40 to +85 36 Ld 6mmx6mm QFN L36.6x6C
ZL2106ALCFTK-01 (Notes 1, 3) 2106-01 -40 to +85 36 Ld 6mmx6mm QFN L36.6x6C
ZL2106EVAL1Z Evaluation Board
NOTES:
1. Please refer to TB347 for details on reel specifications.
2. These Intersil Pb-free plastic packaged products employ special Pb-free material sets; molding compounds/die attach materials and NiPdAu plate - e4
termination finish, which is RoHS compliant and compatible with both SnPb and Pb-free soldering operations. Intersil Pb-free products are MSL classified
at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020.
3. These Intersil Pb-free plastic packaged products employ special Pb-free material sets, molding compounds/die attach materials, and 100% matte
tin plate plus anneal (e3 termination finish, which is RoHS compliant and compatible with both SnPb and Pb-free soldering operations). Intersil Pb-
free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020.
4. For Moisture Sensitivity Level (MSL), please see device information page for ZL2106. For more information on MSL please see techbrief TB363.
ZL2106
5FN6852.5
Table of Contents
Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Thermal Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Recommended Operating Conditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Typical Performance Curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
ZL2106 Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Digital-DC Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Power Conversion Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Power Management Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Multi-mode Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Power Conversion Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Internal Bias Regulators and Input Supply Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
High-side Driver Boost Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Output Voltage Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Start-up Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Soft-start Delay and Ramp Times . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Power-good (PG) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Switching Frequency and PLL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Component Selection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Current Sensing and Current Limit Threshold Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Loop Compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Driver Dead-time Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Power Management Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Input Undervoltage Lockout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Output Overvoltage Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Output Pre-Bias Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Output Overcurrent Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Thermal Overload Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Voltage Tracking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Tracking Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Tracking Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Tracking Configured by Pin-Strap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Voltage Margining . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
I2C/SMBus Communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
I2C/SMBus Device Address Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Digital-DC Bus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Phase Spreading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Output Sequencing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Fault Spreading. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Monitoring via I2C/SMBus. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Snapshot™ Parametric Capture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Non-Volatile Memory and Device Security Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Package Outline Drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Package Outline Drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
ZL2106
6FN6852.5
Absolute Maximum Ratings Thermal Information
DC Supply Voltage for VDDP, VDDS Pins . . . . . . . . . . . . . . . . . . -0.3V to 17V
High-Side Supply Voltage for BST Pin. . . . . . . . . . . . . . . . . . . . . -0.3V to 25V
High-Side Boost Voltage for BST - SW Pins . . . . . . . . . . . . . . . . . -0.3V to 8V
Internal MOSFET Reference for VR Pin . . . . . . . . . . . . . . . . . . -0.3V to 8.5V
Internal Analog Reference for VRA Pin . . . . . . . . . . . . . . . . . . -0.3V to 6.5V
Internal 2.5 V Reference for V2P5 Pin. . . . . . . . . . . . . . . . . . . . . -0.3V to 3V
Logic I/O Voltage for EN, CFG, DDC, FC, MGN, PG, SDA, SCL,
SA, SALRT, SS, SYNC, VTRK, VSET, VSEN Pins . . . . . . . . . . -0.3V to 6.5V
Ground Differential for DGND - SGND,
PGND - SGND Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±0.3V
MOSFET Drive Reference Current for for VR Pin
Internal Bias Usage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20mA
Switch Node Current for SW Pin
Peak (Sink Or Source) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10A
ESD Rating
Human Body Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2kV
Machine Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 500V
Latch-Up. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . per JESD78 (JEDEC Standard)
Thermal Resistance (Typical) θJA (°C/W) θJC (°C/W)
36 Ld QFN (Notes 5, 6) . . . . . . . . . . . . . . . . 28 1
Junction Temperature Range . . . . . . . . . . . . . . . . . . . . . . .-55°C to +150°C
Storage Temperature Range. . . . . . . . . . . . . . . . . . . . . . . .-55°C to +150°C
Dissipation Limits (Note 7)
TA = +25°C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.5W
TA = +55°C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5W
TA = +85°C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4W
Pb-Free Reflow Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . see link below
http://www.intersil.com/pbfree/Pb-FreeReflow.asp
Recommended Operating Conditions
Input Supply Voltage Range, VDDP, VDDS (See Figure 14)
VDDS tied to VR, VRA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5V to 5.5V
VDDS tied to VR, VRA Floating . . . . . . . . . . . . . . . . . . . . . . . . 5.5V to 7.5V
VR, VRA Floating. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.5V to 14V
Output Voltage Range, VOUT (Note 8) . . . . . . . . . . . . . . . . . . . . 0.54V to 5.5V
Operating Junction Temperature Range, TJ . . . . . . . . . . . . .-40°C to +125°C
CAUTION: Do not operate at or near the maximum ratings listed for extended periods of time. Exposure to such conditions may adversely impact product
reliability and result in failures not covered by warranty.
NOTES:
5. θJA is measured in free air with the component mounted on a high effective thermal conductivity test board with “direct attach” features. See Tech
Brief TB379.
6. For θJC, the “case temp” location is the center of the exposed metal pad on the package underside.
7. Thermal impedance depends on layout.
8. Includes margin limits.
Electrical Specifications VDDP = VDDS = 12V, TA = -40°C to +85°C unless otherwise noted. (Note 9) Typical values are at TA = +25°C.
Boldface limits apply over the operating temperature range, -40°C to +85°C.
PARAMETER CONDITIONS
MIN
(Note 19) TYP
MAX
(Note 19) UNIT
Input and Supply Characteristics
IDD Supply Current fSW = 200kHz, no load -11 20 mA
fSW = 1MHz, no load -15 30 mA
IDDS Shutdown Current EN = 0V, No I2C/SMBus activity -0.6 1mA
VR Reference Output Voltage VDD > 8V, IVR < 10mA 6.5 7.0 7.5 V
VRA Reference Output Voltage VDD > 5.5V, IVRA < 20mA 4.5 5.1 5.5 V
V2P5 Reference Output Voltage IV2P5 < 20mA 2.25 2.5 2.75 V
Output Characteristics
Output Current IRMS, Continuous --6A
Output Voltage Adjustment Range (Note 10) VIN > VOUT 0.6 -5.0 V
Output Voltage Setpoint Resolution Set using resistors -10 -mV
Set using I2C/SMBus -±0.025 -% FS
(Note 11)
VSEN Output Voltage Accuracy Includes line, load, temp -1 -1%
VSEN Input Bias Current VSEN = 5.5V -110 200 µA
Soft-start Delay Duration Range (Note 12) Set using SS pin or resistor 2-20 ms
Set using I2C/SMBus 0.002 -500 s
ZL2106
7FN6852.5
Soft-start Delay Duration Accuracy Turn-on delay (precise mode)
(Notes 12, 13)
- ±0.25 - ms
Turn-on delay (normal mode) (Note 14) - -0.25/+4 - ms
Turn-off delay (Note 14) - -0.25/+4 - ms
Soft-start Ramp Duration Range Set using SS pin or resistor 2-20 ms
Set using I2C/SMBus 0-200 ms
Soft-start Ramp Duration Accuracy -100 –µs
Logic Input/output Characteristics
Logic Input Leakage Current Digital pins -250 -250 nA
Logic input low, VIL --0.8 V
Logic input OPEN (N/C) Multi-mode logic pins -1.4 -V
Logic Input High, VIH 2.0 --V
Logic Output Low, VOL IOL ≤ 4mA --0.4 V
Logic Output High, VOH IOH ≥ -2mA 2.25 --V
Oscillator and Switching Characteristics
Switch Node Current, ISW Peak (source or sink) (Note 15) --9A
Switching Frequency Range 200 -1000 kHz
Switching Frequency Set-point Accuracy Predefined settings (Table 9) -5 -5%
PWM Duty Cycle (max) Factory default (Note 16) --95
(Note 17)
%
SYNC Pulse Width (min) 150 --ns
Input Clock Frequency Drift Tolerance External clock source -13 -13 %
rDS(ON) of High Side N-channel FETs ISW = 6A, VGS = 6.5V -60 85 mΩ
rDS(ON) of Low Side N-channel FETs ISW = 6A, VGS = 12V -43 65 mΩ
Tracking
VTRK Input Bias Current VTRK = 5.5V -110 200 µA
VTRK Tracking Ramp Accuracy 100% Tracking, VOUT - VTRK -100 -100 mV
VTRK Regulation Accuracy 100% Tracking, VOUT - VTRK -1 -1%
Fault Protection Characteristics
UVLO Threshold Range Configurable via I2C/SMBus 2.85 -16 V
UVLO Set-point Accuracy -150 -150 mV
UVLO Hysteresis Factory default -3-%
Configurable via I2C/SMBus 0-100 %
UVLO Delay --2.5 µs
Power-good VOUT Threshold Factory default -90 -% VOUT
Power-good VOUT Hysteresis Factory default -5-%
Power-good Delay Using pin-strap or resistor 2-20 ms
Configurable via I2C/SMBus 0-500 s
Electrical Specifications VDDP = VDDS = 12V, TA = -40°C to +85°C unless otherwise noted. (Note 9) Typical values are at TA = +25°C.
Boldface limits apply over the operating temperature range, -40°C to +85°C. (Continued)
PARAMETER CONDITIONS
MIN
(Note 19) TYP
MAX
(Note 19) UNIT
ZL2106
8FN6852.5
VSEN Undervoltage Threshold Factory default -85 -% VOUT
Configurable via I2C/SMBus 0-110 % VOUT
VSEN Overvoltage Threshold Factory default -115 -% VOUT
Configurable via I2C/SMBus 0-115 % VOUT
VSEN Undervoltage Hysteresis -5-% VOUT
VSEN Undervoltage/Overvoltage Fault Response
Time
Factory default -16 -µs
Configurable via I2C/SMBus 5-60 µs
Peak Current Limit Threshold Factory default --9.0 A
Configurable via I2C/SMBus 0.2 -9.0 A
Current Limit Set-point Accuracy -±10 -% FS
(Note 11)
Current Limit Protection Delay Factory default -5-tSW
(Note 18)
Configurable via I2C/SMBus 1-32 tSW
(Note 18)
Thermal Protection Threshold (Junction Temperature) Factory default -125 -°C
Configurable via I2C/SMBus -40 -125 °C
Thermal Protection Hysteresis -15 -°C
NOTES:
9. Refer to Safe Operating Area in Figure 8 and thermal design guidelines in AN2010.
10. Does not include margin limits.
11. Percentage of Full Scale (FS) with temperature compensation applied.
12. The device requires a delay period following an enable signal and prior to ramping its output. Precise timing mode limits this delay period to approx
2ms, where in normal mode it may vary up to 4ms.
13. Precise ramp timing mode is only valid when using EN pin to enable the device rather than PMBus enable. Precise ramp timing mode is automatically
disabled for a self-enabled device (EN pin tied high).
14. The devices may require up to a 4ms delay following the assertion of the enable signal (normal mode) or following the
de-assertion of the enable signal. Precise mode requires Re-Enable delay = TOFF+TFALL+10µs.
15. Switch node current should not exceed IRMS of 6A.
16. Factory default is the initial value in firmware. The value can be changed via PMBus commands.
17. Maximum duty cycle is limited by the equation MAX_DUTY(%) = [1 - (150×10-9 × fSW)] × 100 and not to exceed 95%.
18. tSW = 1/fSW, where fSW is the switching frequency.
19. Compliance to datasheet limits is assured by one or more methods: production test, characterization and/or design.
Electrical Specifications VDDP = VDDS = 12V, TA = -40°C to +85°C unless otherwise noted. (Note 9) Typical values are at TA = +25°C.
Boldface limits apply over the operating temperature range, -40°C to +85°C. (Continued)
PARAMETER CONDITIONS
MIN
(Note 19) TYP
MAX
(Note 19) UNIT
ZL2106
9FN6852.5
Typical Performance Curves For some applications, ZL2106 operating conditions (input voltage, output voltage,
switching frequency, temperature) may require de-rating to remain within the Safe Operating Area (SOA). VIN = VDDP = VDDS, TJ = +125°C
FIGURE 5. LOW-SIDE rDS(ON) vs TJ NORMALIZED FOR TJ = +25°C
(VDDS = 12V, IDRAIN = 0.3A)
FIGURE 6. HIGH-SIDE rDS(ON) vs TJ NORMALIZED FOR TJ = +25°C
(VDDS = 12V, BST – SW = 6.5V, IDRAIN = 0.3A)
FIGURE 7. LOW-SIDE rDS(ON) vs VDDS WITH TJFIGURE 8. SAFE OPERATING AREA, TJ ≤ +125°C
FIGURE 9. MAXIMUM CONVERSION RATIO, TJ ≤ +125°C
0.8
0.9
1.0
1.1
1.2
1.3
1.4
0 25 50 75 100
TJ (°C)
NORMALIZED rDS(ON)
0.8
0.9
1.0
1.1
1.2
1.3
1.4
0 255075100
TJ (°C)
NORMALIZED rDS(ON)
40
45
50
55
60
65
70
6 7 8 9 10 11 12 13
VDDS (V)
rDS(ON) (mΩ)
TJ = +110°C
TJ = +80°C
TJ = +50°C
TJ = +25°C
0
1
2
3
4
5
6
0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
0
1
2
4
5
0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
fSW (MHz)
VOUT (V)
VIN = 6V
VIN = 8.6V TO 14V
VIN = 7.5V
0.60
0.65
0.70
0.75
0.80
0.85
0.90
0.95
0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
fSW (MHz)
VOUT/VIN (V)
VOUT MAY NOT EXCEED
5.5V AT ANY TIME
ZL2106
10 FN6852.5
ZL2106 Overview
Digital-DC Architecture
The ZL2106 is an innovative mixed-signal power conversion and
power management IC based on Zilker Labs patented Digital-DC
technology that provides an integrated, high performance
step-down converter for point of load applications. The ZL2106
integrates all necessary PWM control circuitry as well as low
rDS(ON) synchronous power MOSFETs to provide an extremely
small solution for supplying load currents up to 6A.
Its unique PWM loop utilizes an ideal mix of analog and digital
blocks to enable precise control of the entire power conversion
process with no software required, resulting in a very flexible
device that is also very easy to use. An extensive set of power
management functions are fully integrated and can be
configured using simple pin connections. The user configuration
can be saved in an internal non-volatile memory (NVM).
Additionally, all functions can be configured and monitored via
the SMBus hardware interface using standard PMBus
commands, allowing ultimate flexibility.
Once enabled, the ZL2106 is immediately ready to regulate
power and perform power management tasks with no
programming required. Advanced configuration options and
real-time configuration changes are available via the I2C/SMBus
interface if desired and continuous monitoring of multiple
operating parameters is possible with minimal interaction from a
host controller. Integrated sub-regulation circuitry enables single
supply operation from any external supply between 4.5V and 14V
with no secondary bias supplies needed. The ZL2106 can also be
configured to operate from a 3.3V or 5V standby supply when the
main power rail is not present, allowing the user to configure
and/or read diagnostic information from the device when the
main power has been interrupted or is disabled.
The ZL2106 can be configured by simply connecting its pins
according to the tables provided in the following sections.
Additionally, a comprehensive set of application notes are
available to help simplify the design process. An evaluation
board is also available to help the user become familiar with the
device. This board can be evaluated as a standalone platform
using pin configuration settings. A Windows™-based GUI is also
provided to enable full configuration and monitoring capability
via the I2C/SMBus interface using an available computer and the
included USB cable.
Power Conversion Overview
The ZL2106 operates as a voltage-mode, synchronous buck
converter with a selectable constant frequency pulse width
modulator (PWM) control scheme. The ZL2106 integrates dual low
rDS(ON) synchronous MOSFETs to minimize the circuit footprint.
Figure 10 illustrates the basic synchronous buck converter
topology showing the primary power train components. This
converter is also called a step-down converter, as the output
voltage must always be lower than the input voltage.
V
IN
V
OUT
QH
QL
L1
COUT
ZL
CIN
CB
DB
PWM
LDO
FIGURE 10. SYNCHRONOUS BUCK CONVERTER
DIGITAL
COMPENSATOR
INPUT VOLTAGE BUS
V
OUT
BST
DIGITAL
COMPENSATOR D-PWM
+
Σ
-
VSEN
RESET
SYNC PLL
POWER MANAGEMENT
TEMP
SENSOR
MUX
EN VSETPG
SA
CFG
VR
SW
VDD
COMMUNICATION
REF
SYNC
GEN
VTRK
VDDS
SCL
SDA
SALRT
>>
ADC
ADC
ADC
FC
LDO
VDDP
I
SENSE
HS FET
DRIVER
SS
VRA
I
SENSE
DDC
MGN
NVM
LS FET
DRIVER
DIGITAL
COMPENSATOR
INPUT VOLTAGE BUS
V
OUT
BST
DIGITAL
COMPENSATOR D-PWM
+
Σ
-
VSEN
RESET
SYNC PLL
POWER MANAGEMENT
TEMP
SENSOR
MUX
EN VSETPG
SA
CFG
VR
SW
VDD
COMMUNICATION
REF
SYNC
GEN
VTRK
VDDS
SCL
SDA
SALRT
>>
ADC
ADC
ADC
FC
LDO
VDDP
I
SENSE
HS FET
DRIVER
SS
VRA
I
SENSE
DDC
MGN
NVM
LS FET
DRIVER
FIGURE 11. ZL2106 BLOCK DIAGRAM
ZL2106
11 FN6852.5
The ZL2106 integrates two N-channel power MOSFETs; QH is the
top control MOSFET and QL is the bottom synchronous MOSFET.
The amount of time that QH is on as a fraction of the total
switching period is known as the duty cycle D, which is described
by Equation 1:
During time D, QH is on and VIN – VOUT is applied across the
inductor. The output current ramps up as shown in Figure 12.
When QH turns off (time 1-D), the current flowing in the inductor
must continue to flow from the ground up through QL, during which
the current ramps down. Since the output capacitor COUT exhibits
low impedance at the switching frequency, the AC component of the
inductor current is filtered from the output voltage so the load sees
nearly a DC voltage.
The maximum conversion ratio is shown in Figure 9. Typically,
buck converters specify a maximum duty cycle that effectively
limits the maximum output voltage that can be realized for a
given input voltage and switching frequency. This duty cycle limit
ensures that the low-side MOSFET is allowed to turn on for a
minimum amount of time during each switching cycle, which
enables the bootstrap capacitor to be charged up and provide
adequate gate drive voltage for the high-side MOSFET.
In general, the size of components L1 and COUT as well as the
overall efficiency of the circuit are inversely proportional to the
switching frequency, fSW. Therefore, the highest efficiency circuit
may be realized by switching the MOSFETs at the lowest possible
frequency; however, this will result in the largest component size.
Conversely, the smallest possible footprint may be realized by
switching at the fastest possible frequency but this gives a
somewhat lower efficiency. Each user should determine the
optimal combination of size and efficiency when determining the
switching frequency for each application.
The block diagram for the ZL2106 is illustrated in
Figure 11. In this circuit, the target output voltage is regulated by
connecting the VSEN pin directly to the output regulation point.
The VSEN signal is then compared to an internal reference
voltage that had been set to the desired output voltage level by
the user. The error signal derived from this comparison is
converted to a digital value with an analog to digital (A/D)
converter. The digital signal is also applied to an adjustable
digital compensation filter and the compensated signal is used
to derive the appropriate PWM duty cycle for driving the internal
MOSFETs in a way that produces the desired output.
Power Management Overview
The ZL2106 incorporates a wide range of configurable power
management features that are simple to implement without
additional components. Also, the ZL2106 includes circuit protection
features that continuously safeguard the device and load from
damage due to unexpected system faults. The ZL2106 can
continuously monitor input voltage, output voltage/current and
internal temperature. A Power-good output signal is also included to
enable power-on reset functionality for an external processor.
All power management functions can be configured using either
pin configuration techniques (see Figure 13) or via the
I2C/SMBus interface. Monitoring parameters can also be
pre-configured to provide alerts for specific conditions. See
Application Note AN2033 for more details on SMBus monitoring.
Multi-mode Pins
In order to simplify circuit design, the ZL2106 incorporates
patented multi-mode pins that allow the user to easily configure
many aspects of the device without programming. Most power
management features can be configured using these pins. The
multi-mode pins can respond to four different connections, as
shown in Table 1. These pins are sampled when power is applied
or by issuing a PMBus Restore command (See Application Note
AN2033).
PIN-STRAP SETTINGS
This is the simplest method, as no additional components are
required. Using this method, each pin can take on one of three
possible states: LOW, OPEN, or HIGH. These pins can be
connected to the V2P5 pin for logic HIGH settings as this pin
provides a regulated voltage higher than 2V. Using a single pin
one of three settings can be selected.
IN
OUT
V
V
D≈(EQ. 1)
Voltage
(V)
Time
Current (A)
VIN -V
OUT
0
-VOUT
1 - D
IO
ILPK
ILV
D
FIGURE 12. INDUCTOR WAVEFORM
TABLE 1. MULTI-MODE PIN CONFIGURATION
PIN TIED TO VALUE
LOW
(Logic LOW)
< 0.8VDC
OPEN
(N/C)
No connection
HIGH
(Logic HIGH)
> 2.0VDC
Resistor to SGND Set by resistor value
ZL2106
12 FN6852.5
RESISTOR SETTINGS
This method allows a greater range of adjustability when
connecting a finite value resistor (in a specified range) between
the multi-mode pin and SGND.
Standard 1% resistor values are used, and only every fourth E96
resistor value is used so the device can reliably recognize the
value of resistance connected to the pin while eliminating the
error associated with the resistor accuracy. Up to 31 unique
selections are available using a single resistor.
I2C/SMBUS METHOD
ZL2106 functions can be configured via the I2C/SMBus interface
using standard PMBus commands. Additionally, any value that
has been configured using the pin-strap or resistor setting
methods can also be re-configured and/or verified via the
I2C/SMBus. See Application Note AN2033 for more details.
The SMBus device address and VOUT_MAX are the only
parameters that must be set by external pins. All other device
parameters can be set via the I2C/SMBus. The device address is
set using the SA pin. VOUT_MAX is determined as 10% greater
than the voltage set by the VSET pin.
Resistor pin-straps are recommended to be used for all available
device parameters to allow a safe initial power-up before
configuration is stored via the I2C/SMBus. For example, this can
be accomplished by pin-strapping the undervoltage lockout
threshold (using SS pin) to a value greater than the expected
input voltage, thus preventing the device from enabling prior to
loading a configuration file.
Power Conversion Functional
Description
Internal Bias Regulators and Input Supply
Connections
The ZL2106 employs three internal low dropout (LDO) regulators
to supply bias voltages for internal circuitry, allowing it to operate
from a single input supply. The internal bias regulators are as
follows:
• VR: The VR LDO provides a regulated 7V bias supply for the
high-side MOSFET driver circuit. It is powered from the VDDS
pin and supplies bias current internally. A 4.7µF filter capacitor
is required at the VR pin. The VDDS pin directly supplies the
low-side MOSFET driver circuit.
• VRA: The VRA LDO provides a regulated 5V bias supply for the
current sense circuit and other analog circuitry. It is powered
from the VDDS pin and supplies bias current internally. A
4.7µF filter capacitor is required at the VRA pin.
• V2P5:The V2P5 LDO provides a regulated 2.5V bias supply for
the main controller circuitry. It is powered from the VRA LDO
and supplies bias current internally. A 10µF filter capacitor is
required at the V2P5 pin.
When the input supply (VDDS) is higher than 7.5V, the VR and
VRA pins should not be connected to any other pins. These pins
should only have a filter capacitor attached. Due to the dropout
voltage associated with the VR and VRA bias regulators, the
VDDS pin must be connected to these pins for designs operating
from a supply below 7.5V. Figure 14 illustrates the required
connections for all cases.
Note: The internal bias regulators, VR and VRA, are not designed
to be outputs for powering other circuitry. Do not attach external
loads to any of these pins. Only the multi-mode pins may be
connected to the V2P5 pin for logic HIGH settings.
High-side Driver Boost Circuit
The gate drive voltage for the high-side MOSFET driver is
generated by a floating bootstrap capacitor, CB (see Figure 10).
When the lower MOSFET (QL) is turned on, the SW node is pulled
to ground and the capacitor is charged from the internal VR bias
regulator through diode DB. When QL turns off and the upper
MOSFET (QH) turns on, the SW node is pulled up to VDDP and the
voltage on the bootstrap capacitor is boosted approximately 6.5V
above VDDP to provide the necessary voltage to power the high-
side driver. An internal Schottky diode is used with CB to help
maximize the high-side drive supply voltage.
Output Voltage Selection
The output voltage may be set to any voltage between 0.6V and
5.0V provided that the input voltage is higher than the desired
output voltage by an amount sufficient to prevent the device
from exceeding its maximum duty cycle specification. Using the
pin-strap method, VOUT can be set to one of three standard
voltages as shown in Table 2.
ZL
Multi-mode Pin
ZL
R
SET
Logic
high
Logic
low
Open
Pinstrap
Settings
Resistor
Settings
Multi-mode Pin
FIGURE 13. PIN-STRAP AND RESISTOR SETTING EXAMPLES
TABLE 2. PIN-STRAP OUTPUT VOLTAGE SETTINGS
VSET
VOUT
(V)
LOW 1.2
OPEN 1.5
HIGH 3.3
7.5V < V
IN
≤ 14V4.5V ≤ V
IN
≤ 5.5V 5.5V < V
IN
≤ 7.5V
VR
VRA
VDDS
V
IN
VDDS
VR
VRA
V
IN
VDDS
VR
VRA
V
IN
FIGURE 14. INPUT SUPPLY CONNECTIONS
ZL2106
13 FN6852.5
The resistor setting method can be used to set the output voltage to
levels not available in Table 2. To set VOUT using resistors, use Table
4 to select the resistor that corresponds to the desired voltage.
The output voltage may also be set to any value between 0.6V
and 5.0V using the I2C interface. See Application Note AN2033
for details.
Start-up Procedure
The ZL2106 follows a specific internal start-up procedure after
power is applied to the VDD pins (VDDP and VDDS). Table 3
describes the start-up sequence.
If the device is to be synchronized to an external clock source, the
clock frequency must be stable prior to asserting the EN pin. The
device requires approximately 5ms to 10ms to check for specific
values stored in its internal memory. If the user has stored values
in memory, those values will be loaded. The device will then
check the status of all multi-mode pins and load the values
associated with the pin settings.
Once this process is completed, the device is ready to accept
commands via the I2C/SMBus interface and the device is ready
to be enabled. Once enabled, the device requires approximately
2ms before its output voltage may be allowed to start its
ramp-up process. If a soft-start delay period less than 2ms has
been configured (using PMBus commands), the device will
default to a 2ms delay period. If a delay period greater than 2ms
is configured, the device will wait for the configured delay period
prior to starting to ramp its output.
After the delay period has expired, the output will begin to ramp
towards its target voltage according to the pre-configured soft-
start ramp time that has been set using the SS pin. It should be
noted that if the EN pin is tied to VDDP or VDDS, the device will
still require approximately 5ms to 10ms before the output can
begin its ramp-up as described in Table 3.
Soft-start Delay and Ramp Times
It may be necessary to set a delay from when an enable signal is
received until the output voltage starts to ramp to its target
value. In addition, the designer may wish to set the time required
for VOUT to ramp to its target value after the delay period has
expired. These features may be used as part of an overall inrush
current management strategy or to control how fast a load IC is
turned on. The ZL2106 gives the system designer several options
for precisely and independently controlling both the delay and
ramp time periods.
TABLE 3. ZL2106 START-UP SEQUENCE
STEP # STEP NAME DESCRIPTION TIME DURATION
1 Power Applied Input voltage is applied to the ZL2106’s VDD pins (VDDP and VDDS). Depends on input supply ramp
time
2 Internal Memory Check The device will check for values stored in its internal memory. This step is also
performed after a Restore command.
Approx 5ms to 10ms (device will
ignore an enable signal or PMBus
traffic during this period)
3 Multi-mode Pin Check The device loads values configured by the multi-mode pins.
4 Device Ready The device is ready to accept an enable signal. -
5 Pre-ramp Delay The device requires approximately 2ms following an enable signal and prior to
ramping its output. Additional pre-ramp delay may be configured using the SS pin.
Approximately 2ms
TABLE 4. RESISTORS FOR SETTING OUTPUT VOLTAGE
RSET
(kΩ)
VOUT
(V)
10 0.6
11 0.7
12.1 0.75
13.3 0.8
14.7 0.9
16.2 1.0
17.8 1.1
19.6 1.2
21.5 1.25
23.7 1.3
26.1 1.4
28.7 1.5
31.6 1.6
34.8 1.7
38.3 1.8
42.2 1.9
46.4 2.0
51.1 2.1
56.2 2.2
61.9 2.3
68.1 2.4
75 2.5
82.5 2.6
90.9 2.7
100 2.8
110 2.9
121 3.0
133 3.1
147 3.2
162 3.3
178 5.0
ZL2106
14 FN6852.5
The soft-start delay period begins when the EN pin is asserted
and ends when the delay time expires. The soft-start delay period
is set using the SS pin. Precise ramp delay timing mode reduces
the delay time variations and is available when the appropriate
bit in the MISC_CONFIG register had been set. Please refer to
Application Note AN2033 for details.
The soft-start ramp timer enables a precisely controlled ramp to
the nominal VOUT value that begins once the delay period has
expired. The ramp-up is guaranteed monotonic and its slope may
be precisely set using the SS pin. Using the pin-strap method, the
soft-start delay and ramp times can be set to one of three
standard values according to Table 5.
If the desired soft-start delay and ramp times are not one of the
values listed in Table 5, the times can be set to a custom value by
connecting a resistor from the SS pin to SGND using the
appropriate resistor value from Table 6. The value of this resistor
is measured upon start-up or Restore and will not change if the
resistor is varied after power has been applied to the ZL2106
(see Figure 15).
The soft-start delay and ramp times can also be set to custom
values via the I2C/SMBus interface. When the SS delay time is
set to 0ms, the device will begin its ramp-up after the internal
circuitry has initialized (~2ms). When the soft-start ramp period
is set to 0ms, the output will ramp up as quickly as the output
load capacitance and loop settings will allow. It is generally
recommended to set the soft-start ramp to a value greater than
500µs to prevent inadvertent fault conditions due to excessive
inrush current.
TABLE 5. SOFT-START DELAY AND RAMP SETTINGS
SS PIN SETTING
DELAY AND
RAMP TIME
(ms) UVLO
LOW 2
7.5VOPEN 5
HIGH 10
ZL
SS
R
SS
FIGURE 15. SS PIN RESISTOR CONNECTIONS
TABLE 6. DELAY AND RAMP CONFIGURATION
RSS
(kΩ)
DELAY
TIME
(ms)
RAMP
TIME
(ms)
UVLO
(V)
10 5
5
4.5
11 10
12.1 20
13.3 5
1014.7 10
16.2 20
17.8 5
2
5.5
19.6 10
21.5 20
23.7 5
526.1 10
28.7 20
31.6 5
1034.8 10
38.3 20
42.2 5
2046.4 10
51.1 20
56.2 5
2
7.5
61.9 10
68.1 20
75 5
582.5 10
90.9 20
100 5
10110 10
121 20
133 5
20147 10
162 20
ZL2106
15 FN6852.5
Power-good (PG)
The ZL2106 provides a Power-good (PG) signal that indicates the
output voltage is within a specified tolerance of its target level
and no fault condition exists. By default, the PG pin will assert if
the output is within +15%/-10% of the target voltage. These
limits may be changed via the I2C/SMBus interface. See
Application Note AN2033 for details.
A PG delay period is the time from when all conditions for
asserting PG are met and when the PG pin is actually asserted.
This feature is commonly used instead of an external reset
controller to signal the power supply is at its target voltage prior
to enabling any powered circuitry. By default, the ZL2106 PG
delay is set to 1ms and may be changed using the I2C/SMBus
interface as described in AN2033.
Switching Frequency and PLL
The ZL2106 incorporates an internal phase-locked loop (PLL) to
clock the internal circuitry. The PLL can be driven by an external
clock source connected to the SYNC pin. When using the internal
oscillator, the SYNC pin can be configured as a clock source for
other Zilker Labs devices.
The SYNC pin is a unique pin that can perform multiple functions
depending on how it is configured. The CFG pin is used to select
the operating mode of the SYNC pin as shown in Table 4. Figure
16 illustrates the typical connections for each mode.
CONFIGURATION A: SYNC OUTPUT
When the SYNC pin is configured as an output (CFG pin is tied HIGH),
the device will run from its internal oscillator and will drive the
resulting internal oscillator signal (preset to 400kHz) onto the SYNC
pin so other devices can be synchronized to it. The SYNC pin will not
be checked for an incoming clock signal while in this mode.
CONFIGURATION B: SYNC INPUT
When the SYNC pin is configured as an input (CFG pin is tied
LOW), the device will automatically check for an external clock
signal on the SYNC pin each time the EN pin is asserted. The
internal oscillator will then synchronize with the rising edge of the
external clock. The incoming clock signal must be in the range of
200kHz to 1MHz with a minimum duty cycle and must be stable
when the EN pin is asserted. The external clock signal must also
exhibit the necessary performance requirements (see the
“Electrical Specifications” table beginning on page 6).
In the event of a loss of the external clock signal, the output
voltage may show transient over/undershoot. If this happens, the
ZL2106 will automatically switch to its internal oscillator and
switch at a frequency close to the previous incoming frequency.
CONFIGURATION C: SYNC AUTO DETECT
When the SYNC pin is configured in auto detect mode (CFG pin is left
OPEN), the device will automatically check for a clock signal on the
SYNC pin after enable is asserted. If a valid clock signal is present,
the ZL2106’s oscillator will then synchronize with the rising edge of
the external clock (refer to SYNC INPUT description).
If no incoming clock signal is present, the ZL2106 will configure
the switching frequency according to the state of the SYNC pin as
listed in Table 8. In this mode, the ZL2106 will only read the
SYNC pin connection during the start-up sequence. Changes to
the SYNC pin connection will not affect fSW until the power
(VDDS) is cycled off and on again.
TABLE 7. SYNC PIN FUNCTION SELECTION
CFG PIN SYNC PIN FUNCTION
LOW SYNC is configured as an input
OPEN Auto detect mode
HIGH SYNC is configured as an output fSW = 400kHz
ZL2106
Logic
high
CFG
SYNC
200kHz – 1MHz
ZL2106
CFG
SYNC
200kHz – 1MHz
ZL2106
N/C
CFG
SYNC
200kHz – 1MHz
A) SYNC = output B) SYNC = input
ZL2106
N/C
CFG
SYNC
ZL2106
R
SYN C
N/C
CFG
SYNC
Logic
high
Logic
low
Open
C) SYNC = Auto Detect
OR OR
FIGURE 16. SYNC PIN CONFIGURATIONS
ZL2106
16 FN6852.5
If the user wishes to run the ZL2106 at a frequency not listed in
Table 8, the switching frequency can be set using an external
resistor, RSYNC, connected between SYNC and SGND using Table 9.
The switching frequency can also be set to any value between
200kHz and 1MHz using the I2C/SMBus interface. The available
frequencies are defined by fSW = 8MHz/N, where whole number
N is 8 ≤ N ≤ 40. See Application Note AN2033 for details.
If a value other than fSW = 8MHz/N is entered using a PMBus
command, the internal circuitry will select the valid switching
frequency value that is closest to the entered value. For example,
if 810kHz is entered, the device will select 800kHz (N=10).
Note: The switching frequency read back using the appropriate
PMBus command will differ slightly from the selected value in
Table 9. The difference is due to hardware quantization.
When multiple Zilker Labs devices are used together, connecting
the SYNC pins together will force all devices to synchronize with
each other. The CFG pin of one device must set its SYNC pin as an
output and the remaining devices must have their SYNC pins set
as an input or as auto detect.
Note: Precise ramp timing mode must be disabled to use SYNC
clock auto detect.
Component Selection
The ZL2106 is a synchronous buck converter with integrated
MOSFETs that uses an external inductor and capacitors to
perform the power conversion process. The proper selection of
the external components is critical for optimized performance.
To select the appropriate external components for the desired
performance goals, the power supply requirements listed in
Table 10 must be defined.
DESIGN GOAL TRADE-OFFS
The design of the buck power stage requires several compromises
among size, efficiency and cost. The inductor core loss increases
with frequency, so there is a trade-off between a small output filter
made possible by a higher switching frequency and getting better
power supply efficiency. Size can be decreased by increasing the
switching frequency at the expense of efficiency. Cost can be
minimized by using through-hole inductors and capacitors; however
these components are physically large.
To start the design, select a frequency based on Table 11. This
frequency is a starting point and may be adjusted as the design
progresses.
INDUCTOR SELECTION
The output inductor selection process must include several
trade-offs. A high inductance value will result in a low ripple
current (Iopp), which will reduce output capacitance and produce
a low output ripple voltage, but may also compromise output
transient load performance. Therefore, a balance must be struck
TABLE 8. SWITCHING FREQUENCY SELECTION
SYNC PIN FREQUENCY
LOW 200kHz
OPEN 400kHz
HIGH 1MHz
Resistor See Table 9
TABLE 9. RSYNC RESISTOR VALUES
RSYNC
(kΩ)
FSW
(kHz)
10 200
11 222
12.1 242
13.3 267
14.7 296
16.2 320
17.8 364
19.6 400
21.5 421
23.7 471
26.1 533
28.7 571
31.6 615
34.8 667
38.3 727
42.2 889
46.4 1000
TABLE 10. POWER SUPPLY REQUIREMENTS
PARAMETER RANGE EXAMPLE VALUE
Input Voltage (VIN) 4.5V to 14.0V 12V
Output Voltage (VOUT) 0.6V to 5.0V 3.3V
Output Current (IOUT) 0A to 6A 4A
Output Voltage Ripple (Vorip) < 3% of VOUT ±1% of VOUT
Output Load Step (Iostep)< I
o±25% of Io
Output Load Step Rate - 2.5A/µs
Output Deviation Due to
Load Step
- ±3% of VOUT
Maximum PCB Temp. +120°C +85°C
Desired Efficiency - 85%
Other Considerations - Optimize for small size
TABLE 11. CIRCUIT DESIGN CONSIDERATIONS
FREQUENCY RANGE EFFICIENCY CIRCUIT SIZE
200kHz to 400kHz Highest Larger
400kHz to 800kHz Moderate Smaller
800kHz to 1MHz Lower Smallest
ZL2106
17 FN6852.5
between output ripple and optimal load transient performance. A
good starting point is to select the output inductor ripple equal to
the expected load transient step magnitude (Iostep):
Now the output inductance can be calculated using Equation 3,
where VINM is the maximum input voltage:
The average inductor current is equal to the maximum output
current. The peak inductor current (ILpk) is calculated using
Equation 4 where IOUT is the maximum output current:
Select an inductor rated for the average DC current with a peak
current rating above the peak current computed in Equation 4.
In overcurrent or short-circuit conditions, the inductor may have
currents greater than 2X the normal maximum rated output
current. It is desirable to use an inductor that still provides some
inductance to protect the load and the internal MOSFETs from
damaging currents in this situation.
Once an inductor is selected, the DCR and core losses in the
inductor are calculated. Use the DCR specified in the inductor
manufacturer’s data sheet.
ILrms is given by Equation 6:
where IOUT is the maximum output current. Next, calculate the
core loss of the selected inductor. Since this calculation is
specific to each inductor and manufacturer, refer to the chosen
inductor data sheet. Add the core loss and the DCR loss and
compare the total loss to the maximum power dissipation
recommendation in the inductor data sheet.
OUTPUT CAPACITOR SELECTION
Several trade-offs must also be considered when selecting an
output capacitor. Low ESR values are needed to have a small
output deviation during transient load steps (Vosag) and low
output voltage ripple (Vorip). However, capacitors with low ESR,
such as semi-stable (X5R and X7R) dielectric ceramic capacitors,
also have relatively low capacitance values. Many designs can
use a combination of high capacitance devices and low ESR
devices in parallel.
For high ripple currents, a low capacitance value can cause a
significant amount of output voltage ripple. Likewise, in high
transient load steps, a relatively large amount of capacitance is
needed to minimize the output voltage deviation while the
inductor current ramps up or down to the new steady state
output current value.
As a starting point, apportion one-half of the output ripple
voltage to the capacitor ESR and the other half to capacitance, as
shown in Equations 7 and 8:
Use these values to make an initial capacitor selection, using a
single capacitor or several capacitors in parallel.
After a capacitor has been selected, the resulting output voltage
ripple can be calculated using Equation 9:
Because each part of this equation was made to be less than or
equal to half of the allowed output ripple voltage, the Vorip should
be less than the desired maximum output ripple.
INPUT CAPACITOR
It is highly recommended that dedicated input capacitors be
used in any point-of-load design, even when the supply is
powered from a heavily filtered 5V or 12V “bulk” supply from an
off-line power supply. This is because of the high RMS ripple
current that is drawn by the buck converter topology. This ripple
(ICINrms) can be determined from Equation 10:
Without capacitive filtering near the power supply circuit, this
current would flow through the supply bus and return planes,
coupling noise into other system circuitry. The input capacitors
should be rated at 1.2X the ripple current calculated in Equation
10 to avoid overheating of the capacitors due to the high ripple
current, which can cause premature failure. Ceramic capacitors
with X7R or X5R dielectric with low ESR and 1.1X the maximum
expected input voltage are recommended.
BOOTSTRAP CAPACITOR SELECTION
The high-side driver boost circuit utilizes an internal Schottky
diode (DB) and an external bootstrap capacitor (CB) to supply
sufficient gate drive for the high-side MOSFET driver. CB should
be a 47nF ceramic type rated for at least 10V.
CV2P5 SELECTION
This capacitor is used to both stabilize and provide noise filtering
for the 2.5V internal power supply. It should be between 4.7µF
and 10µF, should use a semi-stable X5R or X7R dielectric
ceramic with a low ESR (less than 10mΩ) and should have a
rating of 4V or more.
CVR SELECTION
This capacitor is used to both stabilize and provide noise filtering
for the 7V reference supply. It should be between 4.7µF and
10µF, should use a semi-stable X5R or X7R dielectric ceramic
capacitor with a low ESR (less than 10mΩ) and should have a
rating of 10V or more. Because the current for the bootstrap
supply is drawn from this capacitor, CVR should be sized at least
ostepopp II =(EQ. 2)
opp
INM
OUT
OUT
OUT Ifsw
V
V
V
L×
⎟
⎟
⎠
⎞
⎜
⎜
⎝
⎛−×
=
1(EQ. 3)
2
opp
OUTLpk
I
II += (EQ. 4)
2
LrmsLDCR IDCRP ×= (EQ. 5)
()
12
2
2opp
OUTLrms
I
II += (EQ. 6)
2
8orip
sw
opp
OUT V
f
I
C
××
=(EQ. 7)
opp
orip
I
V
ESR ×
=2
(EQ. 8)
OUTsw
opp
opporip Cf
I
ESRIV ××
+×= 8
(EQ. 9)
)1( DDII OUTCINrms −××= (EQ. 10)
ZL2106
18 FN6852.5
10X the value of CB so that a discharged CB does not cause the
voltage on it to droop excessively during a CB recharge pulse.
CVRA SELECTION
This capacitor is used to both stabilize and provide noise filtering
for the analog 5V reference supply. It should be between 2.2µF
and 10µF, should use a semi-stable X5R or X7R dielectric
ceramic capacitor with a low ESR (less than 10mΩ) and should
have a rating of 6.3V or more.
THERMAL CONSIDERATIONS
In typical applications, the ZL2106’s high efficiency will limit the
internal power dissipation inside the package. However, in
applications that require a high ambient operating temperature
the user must perform some thermal analysis to ensure that the
ZL2106’s maximum junction temperature is not exceeded.
The ZL2106 has a maximum junction temperature limit of
+125°C, and the internal over-temperature limiting circuitry will
force the device to shut down if its junction temperature exceeds
this threshold. In order to calculate the maximum junction
temperature, the user must first calculate the power dissipated
inside the IC (PQ) as expressed in Equation 11:
The maximum operating junction temperature can then be
calculated using Equation 12:
Where TPCB is the expected maximum printed circuit board
temperature and θJC is the junction-to-case thermal resistance
for the ZL2106 package.
Current Sensing and Current Limit Threshold
Selection
The ZL2106 incorporates a patented “lossless” current sensing
method across the internal low-side MOSFET that is independent
of rDS(ON) variations, including temperature. The default value for
the gain, which does not represent a rDS(ON) value, and the offset
of the internal current sensing circuit can be modified by the
IOUT_CAL_GAIN and IOUT_CAL_OFFSET commands.
The design should include a current limiting mechanism to
protect the power supply from damage and prevent excessive
current from being drawn from the input supply in the event that
the output is shorted to ground or an overload condition is
imposed on the output. Current limiting is accomplished by
sensing the current through the circuit during a portion of the
duty cycle. The current limit threshold is set to 9A by default. The
current limit threshold can set to a custom value via the
I2C/SMBus interface. Please refer to Application Note AN2033
for further details.
Additionally, the ZL2106 gives the power supply designer several
choices for the fault response during over or under current
conditions. The user can select the number of violations allowed
before declaring a fault, a blanking time and the action taken when
a fault is detected. The blanking time represents the time when no
current measurement is taken. This is to avoid taking a reading just
after a current load step (less accurate due to potential ringing).
Please refer to Application note AN2033 for further details.
Loop Compensation
The ZL2106 operates as a voltage-mode synchronous buck
controller with a fixed frequency PWM scheme. Although the
ZL2106 uses a digital control loop, it operates much like a
traditional analog PWM controller. Figure 17 is a simplified block
diagram of the ZL2106 control loop, which differs from an analog
control loop only by the constants in the PWM and compensation
blocks. As in the analog controller case, the compensation block
compares the output voltage to the desired voltage reference and
compensation zeroes are added to keep the loop stable. The
resulting integrated error signal is used to drive the PWM logic,
converting the error signal to a duty cycle to drive the internal
MOSFETs.
()
()
()
()
()
()
()
[]
DRDRIP QLONDSQHONDSLOADQ −+= 1
2(EQ. 11)
()
JCQPCBj PTT θ
max ×+= (EQ. 12)
TABLE 12. RESISTOR SETTING FOR LOOP COMPENSATION
G(dB) Qfsw/fn
FC
(k)
24 0.150 115.000 Open or 11
27 0.150 115.000 Low or 10
27 0.150 69.147 13.3
27 0.150 41.577 14.7
27 0.300 115.000 16.2
27 0.300 69.147 17.8
27 0.300 41.577 19.6
27 0.300 25.000 21.5
27 0.600 69.147 23.7
27 0.600 41.577 26.1
27 0.600 25.000 28.7
30 0.150 115.000 High or 12.1
30 0.150 69.147 31.6
30 0.150 41.577 34.8
30 0.300 115.000 38.3
30 0.300 69.147 42.2
30 0.300 41.577 46.4
30 0.300 25.000 51.1
30 0.600 69.147 56.2
30 0.600 41.577 61.9
30 0.600 25.000 68.1
33 0.150 115.000 75.0
D
1-D
V
IN
V
OUT
L
C
DPWM
R
C
Compensation
R
O
FIGURE 17. CONTROL LOOP BLOCK DIAGRAM
ZL2106
19 FN6852.5
In the ZL2106, the compensation zeros are set by configuring the
FC pin or via the I2C/SMBus interface once the user has
calculated the required settings. This method eliminates the
inaccuracies due to the component tolerances associated with
using external resistors and capacitors required with traditional
analog controllers.
The loop compensation coefficients can also be set via the
I2C/SMBus interface. Please refer to Application Note AN2033
for further details. Also refer to Application Note AN2035 for
further technical details on setting loop compensation.
Driver Dead-time Control
The ZL2106 utilizes a predetermined fixed dead-time applied
between the gate drive signals for the top and bottom MOSFETs.
In a synchronous buck converter, the MOSFET drive circuitry must
be operated such that the top and bottom MOSFETs are never in
the conducting state at the same time. This is because
potentially damaging currents flow in the circuit if both MOSFETs
are on simultaneously for periods of time exceeding a few
nanoseconds. Conversely, long periods of time in which both
MOSFETs are off reduces overall circuit efficiency by allowing
current to flow in their parasitic body diodes.
Therefore, it is advantageous to minimize the dead-time to
provide peak optimal efficiency without compromising system
reliability. The ZL2106 has optimized the dead-time for the
integrated MOSFETs to maximizing efficiency.
Power Management Functional
Description
Input Undervoltage Lockout
The input undervoltage lockout (UVLO) prevents the ZL2106 from
operating when the input falls below a preset threshold,
indicating the input supply is out of its specified range. The UVLO
threshold (VUVLO) can be set to either 4.5V or 10.8V using the SS
pin according to Table 6.
The UVLO voltage can also be set to any value between 2.85V
and 16V via the I2C/SMBus interface.
Once an input undervoltage fault condition occurs, the device
can respond in a number of ways as follows:
1. Continue operating without interruption.
2. Continue operating for a given delay period, followed by
shutdown if the fault still exists. The device will remain in
shutdown until instructed to restart.
3. Initiate an immediate shutdown until the fault has been
cleared. The user can select a specific number of retry
attempts.
The default response from a UVLO fault is an immediate shutdown
of the device. Please refer to Application Note AN2033 for details on
how to configure the UVLO threshold or to select specific UVLO fault
response options via the I2C/SMBus interface.
Output Overvoltage Protection
The ZL2106 offers an internal output overvoltage protection
circuit that can be used to protect sensitive load circuitry from
being subjected to a voltage higher than its prescribed limits. A
hardware comparator is used to compare the actual output
voltage (seen at the VSEN pin) to a threshold set to 15% higher
than the target output voltage (the default setting). If the VSEN
voltage exceeds this threshold, the PG pin will de-assert and the
device can then respond in a number of ways as follows:
1. Initiate an immediate shutdown until the fault has been
cleared. The user can select a specific number of retry
attempts.
2. Turn off the high-side MOSFET and turn on the low-side
MOSFET. The low-side MOSFET remains on until the device
attempts a restart.
The default response from an overvoltage fault is to immediately
shut down. For continuous overvoltage protection when operating
from an external clock, the only allowed response is an
immediate shutdown. Please refer to Application Note AN2033
for details on how to select specific overvoltage fault response
options via I2C/SMBus.
Output Pre-Bias Protection
An output pre-bias condition exists when an externally applied
voltage is present on a power supply’s output before the power
supply’s control IC is enabled. Certain applications require that
the converter not be allowed to sink current during start up if a
pre-bias condition exists at the output. The ZL2106 provides
pre-bias protection by sampling the output voltage prior to
initiating an output ramp.
If a pre-bias voltage lower than the target voltage exists after the
pre-configured delay period has expired, the target voltage is set
to match the existing pre-bias voltage and both drivers are
enabled. The output voltage is then ramped to the final
regulation value at the ramp rate set by the SS pin.
The actual time the output will take to ramp from the pre-bias
voltage to the target voltage will vary depending on the pre-bias
voltage but the total time elapsed from when the delay period
expires and when the output reaches its target value will match
the pre-configured ramp time (see Figure 18).
If a pre-bias voltage higher than the target voltage exists after the
pre-configured delay period has expired, the target voltage is set
to match the existing pre-bias voltage and both drivers are
enabled with a PWM duty cycle that would ideally create the pre-
bias voltage.
33 0.150 69.147 82.5
33 0.150 41.577 90.9
33 0.300 115.000 100.0
33 0.300 69.147 110.0
33 0.300 41.577 121.0
33 0.300 25.000 133.0
33 0.600 69.147 147.0
33 0.600 41.577 162.0
33 0.600 25.000 178.0
TABLE 12. RESISTOR SETTING FOR LOOP COMPENSATION
G(dB) Qfsw/fn
FC
(k)
ZL2106
20 FN6852.5
Once the pre-configured soft-start ramp period has expired, the
PG pin will be asserted (assuming the pre-bias voltage is not
higher than the overvoltage limit). The PWM will then adjust its
duty cycle to match the original target voltage and the output will
ramp down to the pre-configured output voltage.
If a pre-bias voltage higher than the overvoltage limit exists, the
device will not initiate a turn-on sequence and will declare an
overvoltage fault condition to exist. In this case, the device will
respond based on the output overvoltage fault response method
that has been selected. See “Output Overvoltage Protection” on
page 19 for response options due to an overvoltage condition.
Output Overcurrent Protection
The ZL2106 can protect the power supply from damage if the
output is shorted to ground or if an overload condition is imposed
on the output. Once the current limit threshold has been selected
(see “Current Sensing and Current Limit Threshold Selection” on
page 18), the user may determine the desired course of action in
response to the fault condition. The following overcurrent
protection response options are available:
1. Initiate a shutdown and attempt to restart an infinite number
of times with a preset delay period between attempts.
2. Initiate a shutdown and attempt to restart a preset number of
times with a preset delay period between attempts.
3. Continue operating for a given delay period, followed by
shutdown if the fault still exists.
4. Continue operating through the fault (this could result in
permanent damage to the power supply).
5. Initiate an immediate shutdown.
6. The default response from an overcurrent fault is an
immediate shutdown of the device. Please refer to
Application Note AN2033 for details on how to select specific
overcurrent fault response options via I2C/SMBus.
Thermal Overload Protection
The ZL2106 includes an on-chip thermal sensor that
continuously measures the internal temperature of the die and
will shutdown the device when the temperature exceeds the
preset limit. The factory default temperature limit is set to
+125°C, but the user may set the limit to a different value if
desired. See Application Note AN2033 for details. Note that
setting a higher thermal limit via the I2C/SMBus interface may
result in permanent damage to the device. Once the device has
been disabled due to an internal temperature fault, the user may
select one of several fault response options as follows:
1. Initiate a shutdown and attempt to restart an infinite number
of times with a preset delay period between attempts.
2. Initiate a shutdown and attempt to restart a preset number of
times with a preset delay period between attempts.
3. Continue operating for a given delay period, followed by
shutdown if the fault still exists.
4. Continue operating through the fault (this could result in
permanent damage to the power supply).
5. Initiate an immediate shutdown.
If the user has configured the device to restart, the device will
wait the preset delay period (if configured to do so) and will then
check the device temperature. If the temperature has dropped
below a threshold that is approximately +15°C lower than the
selected temperature fault limit, the device will attempt to
re-start. If the temperature still exceeds the fault limit the device
will wait the preset delay period and retry again.
The default response from a temperature fault is an immediate
shutdown of the device. Please refer to Application Note AN2033
for details on how to select specific temperature fault response
options via I2C/SMBus.
Voltage Tracking
High performance systems place stringent demands on the order
in which the power supply voltages turn on. This is particularly
true when powering FPGAs, ASICs, and other advanced processor
devices that require multiple supply voltages to power a single
die. In most cases, the I/O interface operates at a higher voltage
than the core and therefore the core supply voltage must not
exceed the I/O supply voltage according to the manufacturers'
specifications. Voltage tracking protects these sensitive ICs by
limiting the differential voltage among multiple power supplies
during the power-up and power-down sequence. The ZL2106
integrates a lossless tracking scheme that allows its output to
track a voltage that is applied to the VTRK pin with no additional
components required. Figure 19 shows a basic I2C/SMBus
tracking configuration. Please refer to Application Note AN2033
FIGURE 18. OUTPUT RESPONSES TO PRE-BIAS VOLTAGES
ZL2106
21 FN6852.5
for more information on configuring tracking mode using PMBus
commands.
Figure 23 is an example of a basic pin-strap tracking
configuration. The VTRK pin is an analog input that, when
tracking mode is enabled, the voltage applied to the VTRK pin
performs as a reference for the device's output voltage. The
ZL2106 offers two modes of tracking: coincident and ratiometric.
Figures 20 and 21 illustrate the output voltage waveform for the
two tracking modes.
1. Coincident. This mode configures the ZL2106 to ramp its
output voltage at the same rate as the voltage applied to the
VTRK pin. Two options are available for this mode;
a. Track at 100% VOUT limited. Member rail tracks the reference
rail and stops when the member reaches its target voltage,
Figure 20 (A).
b. Track at 100% VTRK limited. Member rail tracks the
reference at the instantaneous voltage value applied to the
VTRK pin, Figure 20 (B).
2. Ratiometric. This mode configures the ZL2106 to ramp its
output voltage as a percentage of the voltage applied to the
VTRK pin. The default setting is 50%, but an external resistor
may be used to configure a different tracking ratio.
a. Track at 50% VOUT limited. Member rail tracks the reference
rail and stops when the member reaches 50% of the target
voltage, Figure 21 (A).
b. Track at 50% VTRK limited. Member rail tracks the reference
at the instantaneous voltage value applied to the VTRK pin
until the member rail reaches 50% of the reference rail
voltage, or if the member is configured to less than 50% of the
reference the member will achieve its configured target,
Figure 21 (B).
Tracking Overview
When the ZL2106 is configured to the voltage tracking mode, the
voltage applied to the VTRK pin acts as a reference for the
member device(s) output regulation. The soft-start values
(Rise/Fall times) are used to calculate the loop gain used during
the turn-on/turn-off ramps, therefore the minimum rise/fall time
has been constrained to 5ms to ensure accuracy. Tracking
accuracy can be improved by increasing the rise and fall times
beyond 5ms.
Tracking Groups
In a tracking group, the device configured to the highest voltage
within the group is defined as the reference device. The device(s)
that track the reference are called the member device(s). The
reference device will control the ramp delay and ramp rate of all
tracking devices and is not placed in the tracking mode.
The reference device is configured to the highest output voltage
for the group and all other device(s) output voltages are meant to
track and never exceed the reference device output voltage.
The reference device must be configured to have a minimum
Time-On Delay and Time-On Rise as shown in Equation 13.
This delay allows the member device(s) to prepare their control
loops for tracking following the assertion of ENABLE.
The member device Time-Off Delay has been redefined to
describe the time that the VTRK pin will follow the reference
voltage after enable is de-asserted. The delay setting sets the
timeout for the member's output voltage to turnoff in the event
that the reference output voltage does not achieve zero volts.
The member device(s) must have a minimum Time-Off Delay of
as shown in Equation 14.
It is assumed for a tracking group, that all of the ENABLE pins are
connected together and driven by a single logic source or PMBus
Broadcast Enable is used.
The configuration settings for Figures 20 and 21 are shown
below in Figure 22. In each case the reference and member rise
times are set to the same value.
FIGURE 19. BASIC I2C TRACKING CONFIGURATION
ZL2106
VTRK SW
SDA SCL
L3
VOUT_M
MEMBER
ZL2106
SW
SCL
SDA
L4
VOUT_R
REFERENCE
SDA
SCL
FIGURE 20. COINCIDENT TRACKING
Track @ 100% Vout Limited
Vref > Vmem
EN
0
EN
0
~
~
~
~
Ton Dly Toff Dly
VRef Vmem
Track @ 100% Vtrk Limited
Vref = Vmem
~
~
To n D ly Toff Dly
VRef Vmem
Coincident Tracking
Vref=1.8V
Vmem=0.9V
Vref=1.8V
Vmem=1.8V
A.
B.
FIGURE 21. RATIOMETRIC TRACKING
0
EN
EN
0
Track @ 50% Vout Limited
Vref = 1.8V
Vmem = 0.9V
~
~~
~
Toff Dly
Ton Dly
Vmem
VRef
Track @ 50% Vtrk Limited
Vref = 1.8V
Vmem = 0.8V
Ratiometric Tracking
Vref=1.8V
Vmem=0.9V
~
~
~
~
Ton Dly Toff Dly
Vref Vmem
Vref=1.8V
Vmem=0.8V
A.
B.
(EQ. 13)
tONDLY(REF) ≥ tONDLY(MEM) + tONRISE(REF) + 5ms ≥ tONDLY(MEM) + 10ms
(EQ. 14)tOFFDLY(MEM) ≥ tOFFDLY(REF) + tOFFFALL(REF) + 5ms
ZL2106
22 FN6852.5
Tracking Configured by Pin-Strap
Tracking is enabled with the CFG pin as shown in Table 16 on
page 24, and configured to a specific ramp rate using the SS pin,
as shown in Table 13 on page 22. Figure 23 shows the basic
schematic of pin-strap tracking.
Voltage Margining
The ZL2106 offers a simple means to vary its output higher or
lower than its nominal voltage setting in order to determine
whether the load device is capable of operating over its specified
supply voltage range. The MGN command is set by driving the
MGN pin or through the I2C/SMBus interface. The MGN pin is a
tri-level input that is continuously monitored and can be driven
directly by a processor I/O pin or other logic-level output.
The ZL2106’s output will be forced higher than its nominal set
point when the MGN command is set HIGH, and the output will
be forced lower than its nominal set point when the MGN
command is set LOW. Default margin limits of VNOM ±5% are pre-
loaded in the factory, but the margin limits can be modified
through the I2C/SMBus interface to as high as VNOM + 10% or as
low as 0V, where VNOM is the nominal output voltage set point
determined by the VSET pin. The ZL2106-01 allows 150% margin
limits.
The margin limits and the MGN command can both be set
individually through the I2C/SMBus interface. Additionally, the
transition rate between the nominal output voltage and either
margin limit can be configured through the I2C/SMBus interface.
Please refer to Application Note AN2033 for detailed instructions
on modifying the margining configurations.
Rail
Vout
Set
(Volts)
TimeOn
Dly
(ms)
TimeOn
Rise
(ms)
TimeOff
Dly
(ms)
TimeOff
Fall
(ms)
Mode
Reference 1.815555TrackDisabled
Member 0.9 5 5 15 5 100%VoutLimited
Rail VoutSet
(Volts)
TimeOn
Dly
(ms)
TimeOn
Rise
(ms)
TimeOff
Dly
(ms)
TimeOff
Fall
(ms)
Mode
Reference 1.815555TrackDisabled
Member 1.8 5 5 15 5 100%VTRKLimited
Rail VoutSet
(Volts)
TimeOn
Dly
(ms)
TimeOn
Rise
(ms)
TimeOff
Dly
(ms)
TimeOff
Fall
(ms)
Mode
Reference 1.815555TrackDisabled
Member 0.9 5 5 15 5 Track50%VoutLimited
Rail VoutSet
(Volts)
TimeOn
Dly
(ms)
TimeOn
Rise
(ms)
TimeOff
Dly
(ms)
TimeOff
Fall
(ms)
Mode
Reference 1.815555TrackDisabled
Member 1.8 5 5 15 5 Track50%VTRKLimited
TrackingConfigurationFigure20(A)
TrackingConfigurationFigure20(B)
TrackingConfigurationFigure21(A)
TrackingConfigurationFigure21(B)
FIGURE 22. TRACKING CONFIGURATION FOR FIGURES 20 AND 21
0.8
FIGURE 23. BASIC PIN-STRAP TRACKING CONFIGURATION
ZL2106
SW
EN
L2
VOUT_M
MEMBER
ZL2106
SW
EN
L1
VOUT_R
REFERENCE
ENABLE
R1 R3 R2 R4
VTRK
CFG SS CFG SS
TABLE 13. TRACKING MODE CONFIGURATION
RSS
(kΩ)
UVLO
(V)
TRACKING RATIO
(%) UPPER TRACK LIMIT RAMP-UP/DOWN BEHAVIOR
19.6
5.5
100
Limited by target voltage Output not allowed to decrease before PG
21.5 Output will always follow VTRK
23.7 Limited by VTRK pin voltage Output not allowed to decrease before PG
26.1 Output will always follow VTRK
28.7
50
Limited by target voltage Output not allowed to decrease before PG
31.6 Output will always follow VTRK
34.8 Limited by VTRK pin voltage Output not allowed to decrease before PG
38.3 Output will always follow VTRK
56.2
7.5
100
Limited by target voltage Output not allowed to decrease before PG
61.9 Output will always follow VTRK
68.1 Limited by VTRK pin voltage Output not allowed to decrease before PG
75 Output will always follow VTRK
82.5
50
Limited by target voltage Output not allowed to decrease before PG
90.9 Output will always follow VTRK
100 Limited by VTRK pin voltage Output not allowed to decrease before PG
110 Output will always follow VTRK
ZL2106
23 FN6852.5
I2C/SMBus Communications
The ZL2106 provides an I2C/SMBus digital interface that enables
the user to configure all aspects of the device operation as well
as monitor the input and output parameters. The ZL2106 can be
used with any standard 2-wire I2C host device.
In addition, the device is compatible with SMBus version 2.0 and
includes an SALRT line to help mitigate bandwidth limitations
related to continuous fault monitoring. Pull-up resistors are
required on the I2C/SMBus as specified in the SMBus 2.0
specification. The ZL2106 accepts most standard PMBus
commands. When controlling the device with PMBus commands,
it is recommended that the enable pin is tied to SGND.
I2C/SMBus Device Address Selection
When communicating with multiple devices using the
I2C/SMBus interface, each device must have its own unique
address so the host can distinguish between the devices. The
device address can be set according to the pin-strap options
listed in Table 14. Address values are right-justified.
If additional device addresses are required, a resistor can be
connected to the SA pin according to Table 15 to provide up to 30
unique device addresses.
Digital-DC Bus
The Digital-DC Communications (DDC) bus is used to
communicate between Zilker Labs Digital-DC devices. This
dedicated bus provides the communication channel between
devices for features such as sequencing and fault spreading. The
DDC pin on all Digital-DC devices in an application should be
connected together. A pull-up resistor is required on the DDC bus
in order to guarantee the rise time as expressed in Equation 15:
Where RPU is the DDC bus pull-up resistance and CLOAD is the bus
loading. The pull-up resistor may be tied to VRA or to an external
3.3V or 5V supply as long as this voltage is present prior to or
during device power-up. As rules of thumb, each device
connected to the DDC bus presents approximately 10pF of
capacitive loading, and each inch of FR4 PCB trace introduces
approximately 2pF. The ideal design will use a central pull-up
resistor that is well matched to the total load capacitance. In
power module applications, the user should consider whether to
place the pull-up resistor on the module or on the PCB of the end
application.
The minimum pull-up resistance should be limited to a value that
enables any device to assert the bus to a voltage that will ensure
a logic 0 (typically 0.8V at the device monitoring point) given the
pull-up voltage (5V if tied to VRA) and the pull-down current
capability of the ZL2106 (nominally 4mA).
TABLE 14. SMBUS DEVICE ADDRESS SELECTION
SA PIN SETTING SMBus ADDRESS
LOW 0x20
OPEN 0x21
HIGH 0x22
(EQ. 15)
Rise Time = RPU •CLOAD ≈ 1µs
TABLE 15. SMBus ADDRESS VALUES
RSA
(kΩ) SMBus Address
10 0x20
11 0x21
12.1 0x22
13.3 0x23
14.7 0x24
16.2 0x25
17.8 0x26
19.6 0x27
21.5 0x28
23.7 0x29
26.1 0x2A
28.7 0x2B
31.6 0x2C
34.8 0x2D
38.3 0x2E
42.2 0x2F
46.4 0x30
51.1 0x31
56.2 0x32
61.9 0x33
68.1 0x34
75 0x35
82.5 0x36
90.9 0x37
100 0x38
110 0x39
121 0x3A
133 0x3B
147 0x3C
162 0x3D
ZL2106
24 FN6852.5
Phase Spreading
When multiple point of load converters share a common DC
input supply, it is desirable to adjust the clock phase offset of
each device such that not all devices start to switch
simultaneously. Setting each converter to start its switching cycle
at a different point in time can dramatically reduce input
capacitance requirements and efficiency losses. Since the peak
current drawn from the input supply is effectively spread out over
a period of time, the peak current drawn at any given moment is
reduced and the power losses proportional to the IRMS2 are
reduced dramatically.
In order to enable phase spreading, all converters must be
synchronized to the same switching clock. The CFG pin is used to
set the configuration of the SYNC pin for each device as
described in “Switching Frequency and PLL” on page 15.
Selecting the phase offset for the device is accomplished by
selecting a device address according to the following equation:
Phase offset = device address x 45°
For example:
• A device address of 0x00 or 0x20 would configure no phase
offset
• A device address of 0x01 or 0x21 would configure 45° of
phase offset
• A device address of 0x02 or 0x22 would configure 90° of
phase offset
The phase offset of each device may also be set to any value
between 0° and 360° in 22.5° increments via the I2C/SMBus
interface. Refer to Application Note AN2033 for further details.
Output Sequencing
A group of Zilker Labs devices may be configured to power up in
a predetermined sequence. This feature is especially useful when
powering advanced processors, FPGAs, and ASICs that require
one supply to reach its operating voltage prior to another supply
reaching its operating voltage in order to avoid latch-up from
occurring. Multi-device sequencing can be achieved by
configuring each device through the I2C/SMBus interface or by
using Zilker Labs patented autonomous sequencing mode.
Autonomous sequencing mode configures sequencing by using
events transmitted between devices over the DDC bus.
The sequencing order is determined using each device’s SMBus
address. Using autonomous sequencing mode (configured using
the CFG pin), the devices must be assigned sequential SMBus
addresses with no missing addresses in the chain. This mode will
also constrain each device to have a phase offset according to its
SMBus address as described in section “Phase Spreading” on
page 24.
The sequencing group will turn on in order starting with the
device with the lowest SMBus address and will continue through
to turn on each device in the address chain until all devices
connected have been turned on. When turning off, the device
with the highest SMBus address will turn off first followed in
reverse order by the other devices in the group.
Sequencing is configured by connecting a resistor from the CFG
pin to ground as described in Table 16. The CFG pin is also used
to set the configuration of the SYNC pin as well as to determine
the sequencing method and order. Please refer to section
“Switching Frequency and PLL” on page 15 for more details on
the operating parameters of the SYNC pin.
Multiple device sequencing may also be achieved by issuing
PMBus commands to assign the preceding device in the
sequencing chain as well as the device that will follow in the
sequencing chain. This method places fewer restrictions on the
SMBus address (no need of sequential address) and also allows
the user to assign any phase offset to any device irrespective of
its SMBus device address.
The Enable pins of all devices in a sequencing group must be tied
together and driven high to initiate a sequenced turn-on of the
group. Enable must be driven low to initiate a sequenced turnoff
of the group. Please refer to Application Note AN2033 for details
on sequencing via the I2C/SMBus interface.
TABLE 16. CFG PIN CONFIGURATIONS FOR SEQUENCING AND
TRACKING
RCFG
SYNC PIN
CONFIGURATION SEQUENCING CONFIGURATION
Low Input
Sequencing and Tracking are
disabled.
Open Auto detect
High Output
10kΩInput
Sequencing and Tracking are
disabled.
11kΩAuto detect
12.1kΩOutput
14.7kΩInput
Device is FIRST in nested
sequence. Tracking disabled.
16.2kΩAuto detect
17.8kΩOutput
21.5kΩInput
Device is LAST in nested
sequence. Tracking disabled.
23.7kΩAuto detect
26.1kΩOutput
31.6kΩInput
Device is MIDDLE in nested
sequence. Tracking disabled.
34.8kΩAuto detect
38.3kΩOutput
46.4kΩInput
Sequence disabled. Tracking
enabled as defined in Table 13.
51.1kΩAuto detect
56.2kΩOutput
ZL2106
25 FN6852.5
Fault Spreading
Digital-DC devices can be configured to broadcast a fault event
over the DDC bus to the other devices in the group. When a
non-destructive fault occurs and the device is configured to shut
down on a fault, the device will shut down and broadcast the
fault event over the DDC bus. The other devices on the DDC bus
will shut down together if configured to do so, and will attempt to
re-start in their prescribed order if configured to do so.
Monitoring via I2C/SMBus
A system controller can monitor a wide variety of different
ZL2106 system parameters through the I2C/SMBus interface.
The device can monitor for fault conditions by monitoring the
SALRT pin, which will be pulled low when any number of
pre-configured fault conditions occur.
The device can also be monitored continuously for any number of
power conversion parameters including input voltage, output
voltage, output current, internal junction temperature, switching
frequency and duty cycle.
The PMBus host should respond to SALRT as follows:
1. ZL device pulls SALRT low.
2. PMBus host detects that SALRT is now low, performs
transmission with Alert Response Address to find which ZL
device is pulling SALRT low.
3. PMBus host talks to the ZL device that has pulled SALRT low.
The actions that the host performs are up to the system
designer.
If multiple devices are faulting, SALRT will still be low after doing
the above steps and will require transmission with the Alert
Response Address repeatedly until all faults are cleared. Please
refer to Application Note AN2033 for details on how to monitor
specific parameters via the I2C/SMBus interface.
Snapshot™ Parametric Capture
The ZL2106 offers a special feature that enables the user to
capture parametric data during normal operation or following a
fault. The Snapshot functionality is enabled by setting bit 1 of
MISC_CONFIG to 1.
See AN2033 for details on using Snapshot in addition to the
parameters supported. The Snapshot feature enables the user to
read the parameters via a block read transfer through the
SMBus. This can be done during normal operation, although it
should be noted that reading the 22 bytes will occupy the SMBus
for some time.
The SNAPSHOT_CONTROL command enables the user to store
the snapshot parameters to Flash memory in response to a
pending fault as well as to read the stored data from Flash
memory after a fault has occurred.
Table 17 describes the usage of this command. Automatic writes
to Flash memory following a fault are triggered when any fault
threshold level is exceeded, provided that the specific fault’s
response is to shut down (writing to Flash memory is not allowed
if the device is configured to re-try following the specific fault
condition).
It should also be noted that the device’s VDD voltage must be
maintained during the time when the device is writing the data to
Flash memory; a process that requires between 700µs to
1400µs depending on whether the data is set up for a block
write. Undesirable results may be observed if the device’s VDD
supply drops below 3.0V during this process.
In the event that the device experiences a fault and power is lost,
the user can extract the last SNAPSHOT parameters stored
during the fault by writing a 1 to SNAPSHOT_CONTROL (transfers
data from Flash memory to RAM) and then issuing a SNAPSHOT
command (reads data from RAM via SMBus).
Non-Volatile Memory and Device Security
Features
The ZL2106 has internal non-volatile memory where user
configurations are stored. Integrated security measures ensure
that the user can only restore the device to a level that has been
made available to them. Refer to “Start-up Procedure” on
page 13 for details on how the device loads stored values from
internal memory during start-up.
During the initialization process, the ZL2106 checks for stored
values contained in its internal memory. The ZL2106 offers two
internal memory storage units that are accessible by the user as
follows:
1. Default Store: A power supply module manufacturer may
want to protect the module from damage by preventing the
user from being able to modify certain values that are related
to the physical construction of the module. In this case, the
module manufacturer would use the Default Store and would
allow the user to restore the device to its default setting but
would restrict the user from restoring the device to the factory
settings.
2. User Store: The manufacturer of a piece of equipment may
want to provide the ability to modify certain power supply
settings while still protecting the equipment from modifying
values that can lead to a system level fault. The equipment
manufacturer would use the User Store to achieve this goal.
Please refer to Application Note AN2033 for details on how to set
specific security measures via the I2C/SMBus interface.
TABLE 17. SNAPSHOT_CONTROL COMMAND
DATA
VALUE DESCRIPTION
1 Copies current SNAPSHOT values from Flash memory to
RAM for immediate access using SNAPSHOT command.
2 Writes current SNAPSHOT values to Flash memory. Only
available when device is disabled.
ZL2106
26 FN6852.5
Revision History
The revision history provided is for informational purposes only and is believed to be accurate, but not warranted. Please go to web to make
sure you have the latest Rev.
DATE REVISION CHANGE
3/31/11 FN6852.5 In “Absolute Maximum Ratings” on page 6, changed following from:
High-Side Supply Voltage for BST Pin . . . . . . . . . . . . . . . . . . . . .-0.3V to 30V
to:
High-Side Supply Voltage for BST Pin . . . . . . . . . . . . . . . . . . . . .-0.3V to 25V
12/16/10 FN6852.4 Added following parts to “Ordering Information” on page 4:
ZL2106ALCF-01
ZL2106ALCFT-01
ZL2106ALCFTK-01
ZL2106ALCF
ZL2106ALCFT
ZL2106ALCFTK
Added corresponding Pb-free lead finish note (Note 3)
Added corresponding Package Outline Drawing L36.6x6C to page 30.
In “Voltage Margining” on page 22, changed the last sentence in the 2nd paragraph from "A safety feature prevents the user from
configuring the output voltage to exceed VNOM + 10% under any conditions." to "The ZL2106-01 allows 150% margin limits."
12/15/10 FN6852.3 Updated over temp note in MIN MAX columns of spec table from "Parameters with MIN and/or MAX limits are 100% tested at
+25°C, unless otherwise specified. Temperature limits established by characterization and are not production tested." to new
standard "Compliance to datasheet limits is assured by one or more methods: production test, characterization and/or design."
Removed Note "Limits established by characterization and are not production tested." and all references to it.
11/30/10 Added following statement to disclaimer on page 31: “This product is subject to a license from Power One, Inc. related to digital
power technology as set forth in U.S. Patent No. 7,000,125 and other related patents owned by Power One, Inc. These license
rights do not extend to stand-alone POL regulators unless a royalty is paid to Power One, Inc.”
7/9/10 Text above Equation 13 changed
From: The reference device must be configured to have a minimum Time-On Delay of 10ms greater than the member device as
shown in Equation 13.
To: The reference device must be configured to have a minimum Time-On Delay and Time-On Rise as shown in Equation 13.
Made correction to Equation 13 to read
From: tONDLY(REF) >/- tONRISE(REF) + 5ms
To: tONDLY(REF) ≥ tONDLY(MEM) + tONRISE(REF) + 5ms ≥ tONDLY(MEM) + 10ms
Figure 22, last row changed
From: 1.8 5 5 15 5
To: 0.8 5 5 15 5
7/1/10 Revamped Voltage Tracking Section adding details about the tracking feature. Changed in Page 1, 1st paragraph "The ZL2106
is an innovative power conversion..." to "The ZL2106 is a digital power conversion..."
Made correction to Figure 19 - Connected SDA and SCL to Member device.
Made correction to Figure 23 by changing SDA and SCL labels in each device to “EN”. Added word “Enable” and added labels
CFG, SS, R1, R3, R2 and R4.
Changed in Voltage Tracking - Ratiometric on page 23 first sentence changed from:
“This mode configures the ZL2106 to ramp its output voltage at a rate that is a percentage of the voltage applied to the VTRK
pin”. to “This mode configures the ZL2106 to ramp its output voltage as a percentage of the voltage applied to the VTRK pin”.
Titles of Table in Figure 22 changed from “Tracking Configuration Example 1A, 1B, 2A, 2B” to “Tracking Configuration Figure 20
(A), 20 (B), 21 (A), 21 (B)”.
Figures 20and 21 added “0” and “EN” to Timing Tracking Graphics.
02/11/10 FN6852.2 Typo on Page 24, Table 15, resistor values 34.8 and 31.6 swapped so that 31.6 is 0x2C and 34.8 is 0x2D in the table.
ZL2106
27 FN6852.5
11/20/09 FN6852.1 On page 16. Table 9. “RSYNC RESISTOR VALUES”. Changed values of last 4 rows from:
34.8kohm | 727kHz
38.3kohm | 800kHz
46.4kohm | 889kHz
51.1kohm | 1000kHz
to:
34.8kohm | 667kHz
38.3kohm | 727kHz
42.2kohm | 889kHz
46.4kohm | 1000kHz
10/13/09 Removed “SNAPSHOT PARAMETERS” table. Added “See AN2033 for details on using Snapshot in addition to the parameters
supported. “ to “Snapshot™ Parametric Capture ” on page 25
10/1/09 1) Updated to new format. Updates include:
a) Moving Typical Application Circuits to front of datasheet, per new standard
b) Putting Abs Max, Recommended Operating Conditions and Electrical Specs tables into Intersil format
- Adding Pb-free reflow link to Thermal info
- Adding Intersil's caution statement, per legal
- Added ESD ratings
c) Put Ordering Info table into Intersil format
- Adding Moisture Sensitivity Level note, TB347 tape and reel spec note and Pb-free note (corresponding to lead finish).
Added evaluation board.
d) Updated sales disclaimer on last page to Intersil's verbiage
e) Replaced Zilker POD with Intersil equivalent POD (L36.6x6A)
f) Updated graphics to Intersil standards (font change)
g) Updated cross references to tables (since table #s were removed from Electrical Specs, Abs Max, Recommended Operating
Conditions and Pin Descriptions tables)
h) Updated cross references to figures (since figure #s were removed from Block Diagram and Pinout)
i) Added equation #s to all equations
j) Added Intersil standard over temp notes to Electrical Specs table as follows:
- Added Note 19: "Parameters with MIN and/or MAX limits are 100% tested at +25°C, unless otherwise specified.
Temperature limits established by characterization and are not production tested." to MIN MAX columns of Electrical Specs
table.
-Added "Boldface limits apply over the operating temperature range, -40°C to +85°C" to common conditions of Electrical
Specs table. Bolded all MIN and MAX specs in table.
k) Revised page 1. Shortened Features and added Efficiency curve
2) On page 6; Removed "low" from the “Power-good VOUT Low Threshold” line in the Electrical Specs table
3) On page 14; “SOFT-START DELAY AND RAMP SETTINGS” table (was Table 9, now Table 5): Changed UVLO from 4.5V to 7.5V
4) On page 14; “DELAY AND RAMP CONFIGURATION” table (was Table 10, now Table 6): Ramp Time and Delay Time swapped
columns and values changed. Updated UVLO values.
5) On page 10; 2nd column, removed 2nd paragraph "Application notes and reference .. .. to order an evaluation kit."
6) On page 22; Table 13, “TRACKING MODE CONFIGURATION”, changed UVLO values "4.5" to "5.5" and "10.8" to "7.5"
7) On page 22; Table 13, “TRACKING MODE CONFIGURATION”, changed Rss values from:
"42.2" to "56.2"
"46.4" to "61.9"
"51.1" to "68.1"
"56.2" to "75"
"61.9" to "82.5"
"68.1" to "90.9"
"75" to "100"
"82.5" to "110"
8) In Thermal Information, changed Thermal Tja from “35” to “28” and Tjc from “5” to “1”
10) In Thermal Information, changed Dissipation Limits from “3.25W, 2.25W, 1.25W” to “3.5W, 2.5W, 1.4W”
9) In Spec table, changed conditions for VRA and V2P5 Reference Output Voltage from “50mA” to “20mA”
10) In Spec table, added Reference Note 19 (Limits established by characterization and not production tested) to Soft-start
Delay Duration in conditions.
11) Changed Part Numbers in Ordering Information from From “ZL2106ALBN, ZL2106ALBNT,
ZL2106ALBNTK” to “ZL2106ALCN, ZL2106ALCNT, ZL2106ALCNTK”
Revision History
The revision history provided is for informational purposes only and is believed to be accurate, but not warranted. Please go to web to make
sure you have the latest Rev. (Continued)
DATE REVISION CHANGE
ZL2106
28
Intersil products are manufactured, assembled and tested utilizing ISO9000 quality systems as noted
in the quality certifications found at www.intersil.com/design/quality
Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time
without notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be
accurate and reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third
parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries.
This product is subject to a license from Power One, Inc. related to digital power technology as set forth in U.S. Patent No. 7,000,125 and other related patents
owned by Power One, Inc. These license rights do not extend to stand-alone POL regulators unless a royalty is paid to Power One, Inc.
For information regarding Intersil Corporation and its products, see www.intersil.com
FN6852.5
For additional products, see www.intersil.com/product_tree
Products
Intersil Corporation is a leader in the design and manufacture of high-performance analog semiconductors. The Company's products
address some of the industry's fastest growing markets, such as, flat panel displays, cell phones, handheld products, and notebooks.
Intersil's product families address power management and analog signal processing functions. Go to www.intersil.com/products for a
complete list of Intersil product families.
*For a complete listing of Applications, Related Documentation and Related Parts, please see the respective device information page
on intersil.com: ZL2106
To report errors or suggestions for this datasheet, please go to www.intersil.com/askourstaff
FITs are available from our website at http://rel.intersil.com/reports/search.php
02/19/09 FN6852.0 Assigned file number FN6852 to datasheet as this will be the first release with an Intersil file number. Replaced header and
footer with Intersil header and footer. Updated disclaimer information to read “Intersil and it’s subsidiaries including Zilker Labs,
Inc.” No changes to datasheet content
11/08 1.1 1) Added Notes 1, 5, 8 and 9 to Electrical Specifications Table
2) Corrected Tj = 25 °C in Figures 5 and 6
3) Added Tj ≤ 125°C in Figures 8 and 9
4) Added last paragraph to “Multi-mode Pins” on page 11
5) Changed PG delay to 1ms in “Power-good (PG)” on page 15
6) Added note for SYNC clock auto detect in “Switching Frequency and PLL” Section
7) Updated first paragraph of “Current Sensing and Current Limit Threshold Selection” on page 18
8) Changed default fault response to immediate shutdown in “Input Undervoltage Lockout” on page 19, “Output Overvoltage
Protection” on page 19, “Output Overcurrent Protection” on page 20 and “Thermal Overload Protection” on page 20.
9) Updated Ordering Information
8/08 1.0 Initial Release
Revision History
The revision history provided is for informational purposes only and is believed to be accurate, but not warranted. Please go to web to make
sure you have the latest Rev. (Continued)
DATE REVISION CHANGE
ZL2106
29 FN6852.5
Package Outline Drawing
L36.6x6A
36 LEAD QUAD FLAT NO-LEAD PLASTIC PACKAGE
Rev 1, 9/09
located within the zone indicated. The pin #1 indentifier may be
Unless otherwise specified, tolerance : Decimal ± 0.05
Tiebar shown (if present) is a non-functional feature.
The configuration of the pin #1 identifier is optional, but must be
between 0.15mm and 0.30mm from the terminal tip.
Dimension b applies to the metallized terminal and is measured
Dimensions in ( ) for Reference Only.
Dimensioning and tolerancing conform to AMSE Y14.5m-1994.
6.
either a mold or mark feature.
3.
5.
4.
2.
Dimensions are in millimeters.1.
NOTES:
BOTTOM VIEW
DETAIL "X"
SIDE VIEW
TYPICAL RECOMMENDED LAND PATTERN
TOP VIEW
( 4. 10 )
( 5. 60 TYP )
(36X 0.25 )
( 36X 0.80 )
( 36 X 0 . 50 )
0 . 00 MIN.
0 . 05 MAX.
0 . 2 REF
C
MAX 0.90
5
0.10 C
0.08 C
C
6.00
(4X) 0.15
6
PIN 1
INDEX AREA
6.00
B
A
4 .10 ± 0.10
36X 0.60 ± 0.10 36X 0.25
C0.10 M A B
4
19
18
9
10
PIN #1
27
28
36X
1
36
0.50 6
4.0
4X
INDEX AREA
Compliant to JEDEC MO-220VJJD.
7.
ZL2106
30 FN6852.5
Package Outline Drawing
L36.6x6C
36 LEAD QUAD FLAT NO-LEAD PLASTIC PACKAGE
Rev 0, 4/10
located within the zone indicated. The pin #1 identifier may be
Unless otherwise specified, tolerance : Decimal ± 0.05
Tiebar shown (if present) is a non-functional feature.
The configuration of the pin #1 identifier is optional, but must be
between 0.15mm and 0.30mm from the terminal tip.
Dimension applies to the metallized terminal and is measured
Dimensions in ( ) for Reference Only.
Dimensioning and tolerancing conform to ASME Y14.5m-1994.
6.
either a mold or mark feature.
3.
5.
4.
2.
Dimensions are in millimeters.1.
NOTES:
BOTTOM VIEW
DETAIL "X"
SIDE VIEW
TYPICAL RECOMMENDED LAND PATTERN
TOP VIEW
JEDEC reference drawing: MO-220VJJD.
7.
( 4. 10 )
( 5. 60 TYP )
(36X 0.25 )
( 36X 0.80 )
( 36 X 0 . 50 )
0 . 00 MIN.
0 . 05 MAX.
0 . 2 REF
C
MAX 1.00
5
0.10 C
0.08 C
C
6.00
(4X) 0.15
6
PIN 1
INDEX AREA
6.00
B
A
SEE DETAIL "X"
4 .10 ± 0.10
36X 0.60 ± 0.10 36X 0.25
C0.10 M A B
4
19
18
9
10
PIN #1
27
28
36X
1
36
0.50 6
4.04X
INDEX AREA
