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Application Note 1517
ZL2008EVAL1Z Evaluation Board
Description
The ZL2008 is an integrated mixed-signal power
conversion and management IC that combines an
efficient step-down DC/DC converter with key power and
thermal management functions in a single package. The
ZL2008 incorporates current sharing and adaptive
efficiency-optimization algorithms to provide a flexible,
efficient power IC building block.
The ZL2008EVAL1Z platform is a 4-layer board
demonstrating a 15A synchronous buck converter.
Sequencing, tracking, margining, plus other features can
be evaluated using this board.
A USB to SMBus adapter board can be used to connect
the eval board to a PC. The PMBus command set is
accessed by using the Zilker Labs PowerNavigator™
evaluation software from a PC running Microsoft
Windows.
Features
• 15A synchronous buck converter
• Optimized for small circuit footprint and dynamic
response
•Configurable through SMBus
• Onboard enable switch
• Power good indicator
Target Specifications
•V
IN = 12V
•V
OUT = 1.2V/15A (20A max)
•f
sw = 615kHz
• Efficiency: 86% at 10A
• Output ripple: ±1%
• Dynamic response: ±3%
(50%-100%-50% load step, di/dt = 2.5A/μs)
• Board temperature: +25°C
FIGURE 1. ZL2008EVAL1Z BLOCK DIAGRAM
V
IN
DDC
SMBus
V
OUT
EN
SYNC
ENABLE
SW 1
J10 J11
SYNC
DDC
SMBus
TRA CK
SYNC
DDC
SMBus
TRA CK
PG
VTRK
PG
PINSTRAP
ZL2008
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774 |Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright Intersil Americas Inc. 2009, 2010. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.
March 15, 2010
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Functional Description
The ZL2008EVAL1Z provides all circuitry required to
demonstrate the features of the ZL2008. The
ZL2008EVAL1Z has a functionally-optimized ZL2008
circuit layout that allows efficient operation up to the
maximum output current. Power and load connections
are provided through plug-in sockets.
A majority of the features of the ZL2008 such as soft-
start delay and ramp times, supply sequencing, voltage
tracking, and voltage margining are available on this
evaluation board. For voltage tracking and sequencing
evaluation, the board can be connected to any other
Zilker Labs evaluation board that supports the Digital DC
(DDC) bus.
Figure 1 shows a functional block diagram of the
ZL2008EVAL1Z board. The SMBus address is selectable
through a jumper on the top side of the board. All power
to the board (VIN and I2C bus) must be removed before
changing the jumpers.
The hardware enable function is controlled by a toggle
switch on the ZL2008EVAL1Z board. The power good
(PG) LEDs indicate the correct state of PG when external
power is applied to the ZL2008EVAL1Z board. The right
angle headers at opposite ends of the board are for
connecting a USB to SMBus adapter board or for daisy
chaining of multiple evaluation boards.
Figure 2 shows the operational circuit. The circuit
consists of the ZL2008 IC with its minimal component
count to realize a 15A buck converter. The board layout
has been optimized for thermal performance. Figure 3 is
the board interface circuitry. Figure 4 through Figure 8
show the PCB layout for the board including the board
fabrication notes.
The bill of materials (BOM) and configuration file are also
included for reference.
Operation
PMBus Operation
The ZL2008 utilizes the PMBus protocol. The PMBus
functionality can be controlled via USB from a PC running
the PowerNavigator evaluation software in a Windows XP
or Windows 2000/NT operating system.
Install the evaluation software using the CD included in
the ZL2008EVAL1Z kit.
For board operation, connect the included USB-to-SMBus
adapter board to J10 of the ZL2008EVAL1Z board.
Connect the desired load and an appropriate power
supply to the input and connect the included USB cable
to the PC running the PowerNavigator evaluation
software. Place the ENABLE switch in “DISABLE” and turn
on the power.
The evaluation software allows modification of all ZL2008
PMBus parameters. The ZL2008 device on the board has
been pre-configured as described in this document, but
the user may modify the operating parameters through
the eval software or by loading a predefined scenario
from a configuration file.
Use the mouse-over pop-ups for PowerNavigator help.
Refer to Zilker Labs application note AN2033 for PMBus
details.
The ENABLE switch can then be moved to “ENABLE” and
the ZL2008EVAL1Z board can be tested. Alternately, the
PMBus ON-OFF CONFIG and OPERATION commands may
be used.
Quick Start Guide
Stand Alone Operation
1. Set ENABLE switch to “DISABLE”
2. Apply load to VOUT+/VOUT-
3. Connect the USB to SMBus adapter board to J10 of
ZL2008EVAL1Z
4. Connect supplied USB cable from computer to USB
to SMBus adapter board
5. Connect power supply to VIN+/VIN- (supply turned
off)
6. Turn power supply on
7. Set ENABLE switch to “ENABLE”
8. Monitor ZL2008EVAL1Z board operation using an
oscilloscope
USB (PMBus) Operation
1. Set ENABLE switch to “DISABLE”
2. Apply load to VOUT+/VOUT-
3. Connect power supply to VIN+/VIN- (supply turned
off)
4. Turn power supply on
5. Insert the Zilker Labs Eval Kit CD
6. Connect USB to SMBus adapter board to J10 of
ZL2008EVAL1Z
7. Connect supplied USB cable from computer to USB
to SMBus adapter board
- Upon first-time connection, the Found New
Hardware Wizard will appear.
- Windows XP users: Select ‘No’ at prompt to
search the Internet for drivers.
- Follow the steps on the screen to install the
drivers from the CD.
8. Install the PowerNavigator evaluation software by
running setup.exe from the
PowerNavigator_installer folder on the CD.
9. Set ENABLE switch on EVB to “ENABLE”
10.Monitor and configure the ZL2008EVAL1Z board
using PMBus commands in the evaluation software
11.Test the ZL2008EVAL1Z operation using an
oscilloscope and the evaluation software.
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Board Schematics
FIGURE 2. ZL2008EVAL1Z OPERATIONAL CIRCUIT
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FIGURE 3. ZL2008EVAL1Z INTERFACE CIRCUITRY
Board Schematics (Continued)
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Board Layout – 4 Layers
FIGURE 4. PCB – TOP LAYER
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FIGURE 5. PCB – INNER LAYER 1 (VIEWED FROM TOP)
Board Layout – 4 Layers (Continued)
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FIGURE 6. PCB – INNER LAYER 2 (VIEWED FROM TOP)
Board Layout – 4 Layers (Continued)
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FIGURE 7. PCB – BOTTOM LAYER (VIEWED FROM TOP)
Board Layout – 4 Layers (Continued)
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FIGURE 8. BOARD FABRICATION NOTES
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Bill of Materials
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Configuration Text
The following configuration text is loaded into the ZL2008 device on the ZL2008EVAL1Z. The configuration is stored in
the DEFAULT store. Each PMBus command can be viewed via the PowerNavigator software. The text following the #
symbol is used for a comment.
#ZL2008
#PowerPlan file
#11/30/2009
#NOTE: This file is intended for the ZL2008EVAL1Z
#with L=400nH, Co=5x(100uF/2.0mohm)+(2X680uF/10mohm)
#Configuration File Format:
#PMBus Command <tab> Hex Value
#Erase user store & default store
RESTORE_FACTORY
STORE_USER_ALL
STORE_DEFAULT_ALL
MFR_ID Zilker_Labs
MFR_MODEL ZL2008EVAL1Z
MFR_REVISION Rev7
MFR_LOCATION Austin_TX
#MFR_DATE
VOUT_COMMAND 1.20#V
IOUT_SCALE 0.7 #mOhm
IOUT_CAL_OFFSET 2 #A
IOUT_OC_FAULT_LIMIT 45.0 #A
IOUT_AVG_OC_FAULT_LIMIT 38.0 #A
IOUT_UC_FAULT_LIMIT -15.0 #A
IOUT_AVG_UC_FAULT_LIMIT -12.0 #A
MFR_IOUT_OC_FAULT_RESPONSE 0x80
MFR_IOUT_UC_FAULT_RESPONSE 0x80
VIN_OV_FAULT_LIMIT 14.0 #V
VIN_OV_WARN_LIMIT 13.5 #V
VIN_OV_FAULT_RESPONSE 0x80
VIN_UV_WARN_LIMIT 4.641 #V
VIN_UV_FAULT_LIMIT 4.50 #V
VIN_UV_FAULT_RESPONSE 0x80
POWER_GOOD_DELAY 1 #ms
TON_DELAY 5 #ms
TON_RISE 5 #ms
TOFF_DELAY 5 #ms
TOFF_FALL 5 #ms
DEADTIME 0x2424
DEADTIME_CONFIG 0x0404
MAX_DUTY 95
INDUCTOR 0.4 #uH
FREQUENCY_SWITCH 400 #kHz
PID_TAPS A=13682.50, B=-23641.00, C=9993.75
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# Advanced
USER_CONFIG 0x6010
MFR_CONFIG 0x6AD5
#NLR_CONFIG 0xE1060C00
TEMPCO_CONFIG 0xA8
# Advanced 2
MISC_CONFIG 0x0080
DDC_CONFIG 0x0101
DDC_GROUP 0x00000000
STORE_DEFAULT_ALL
RESTORE_DEFAULT_ALL
Configuration Text (Continued)
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Measured Data
The following data was acquired using a ZL2008EVAL1Z rev 2 evaluation board.
Efficiency
Adaptive diode emulation and adaptive frequency modes are disabled for these efficiency measurements.
FIGURE 9. EFFICIENCY, VIN = 12V, VOUT = 1.2V
Ramp-up/Ramp-down Characteristics
FIGURE 10. RAMP UP FIGURE 11. RAMP DOWN
Dynamic Load Response
FIGURE 12. DYNAMIC RESPONSE, 7A TO 15A LOAD
STEP
FIGURE 13. DYNAMIC RESPONSE, 15A TO 7A LOAD
STEP
74
76
78
80
82
84
86
88
90
0 8 10 12 14 16
OUTPUT CURRENT (A)
EFFICIENCY (%)
246
-0.2
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.10
TIME (s)
OUTPUT VOLTAGE (V)
-0.2
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.10
TIME (s)
OUTPUT VOLTAGE (V)
-0.020
-0.015
-0.010
-0.005
0
0.005
0 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18 0.2
0
TIME (µs)
V
OUT
(V)
-0.010
-0.005
0
0.005
0.010
0.015
0.020
0.025
0.030
0 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18 0.20
TIME (µs)
VOUT (V)
Application Note 1517
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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 the Application Note or Technical Brief is current before proceeding.
For information regarding Intersil Corporation and its products, see www.intersil.com
AN1517.1
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References
ZL2008 Data Sheet, Zilker Labs, Inc., 2008.
AN2033 – PMBus
™
Command Set, Zilker Labs, Inc., 2008.
Ordering Information
ORDERABLE
PART NUMBER DESCRIPTION
ZL2008EVAL1Z ZL2008 Evaluation Kit (EVB, USB Adapter, Cable, Software)
Revision History
DATE REV. # DESCRIPTION
March 2010 AN1517.1 In “Target Specifications” on page 1, changed “Dynamic response: ±2.5%” to
"Dynamic response: ±3%"
December 2009 AN1517.0 Initial release
Application Note 1517
