ZY7120LG-T1 - Power-One - Datasheet.Live

ZY7120 20A DC-DC Intelligent POL Data Sheet

3V to 13.2V Input  0.5V to 5.5V Output

ZD-00194 Rev. 2.5, 01-Jul-10 www.power-one.com Page 1 of 34

Member of the Family

Applications

 Low voltage, high density systems with

Intermediate Bus Architectures (IBA)

 Point-of-load regulators for high performance DSP,

FPGA, ASIC, and microprocessor applications

 Desktops, servers, and portable computing

 Broadband, networking, optical, and

communications systems

 Active memory bus terminators

Benefits

 Integrates digital power conversion with intelligent

power management

 Eliminates the need for external power

management components

 Completely programmable via industry-standard

I2C communication bus

 One part that covers all applications

 Reduces board space, system cost and

complexity, and time to market

Features

 RoHS lead free and lead-solder-exempt products are

available

 Wide input voltage range: 3V–13.2V

 High continuous output current: 20A

 Wide programmable output voltage range: 0.5V–5.5V

 Active digital current share

 Single-wire serial communication bus for frequency

synchronization, programming, and monitoring

 Optimal voltage positioning with programmable slope

of the VI line

 Overcurrent, overvoltage, undervoltage, and

overtemperature protections with programmable

thresholds and types

 Programmable fixed switching frequency 0.5-1.0MHz

 Programmable turn-on and turn-off delays

 Programmable turn-on and turn-off voltage slew rates

with tracking protection

 Programmable feedback loop compensation

 Power Good signal with programmable limits

 Programmable fault management

 Start up into the load pre-biased up to 100%

 Full rated current sink

 Real time voltage, current, and temperature

measurements, monitoring, and reporting

 Small footprint SMT package: 8x32mm

 Low profile of 14mm

 Compatible with conventional pick-and-place

equipment

 Wide operating temperature range

 UL60950 recognized, CSA C22.2 No. 60950-00

certified, and TUV EN60950-1:2001 certified

Description

Power-One’s point-of-load converters are recommended for use with regulated bus converters in an Intermediate

Bus Architecture (IBA). The ZY7120 is an intelligent, fully programmable step-down point-of-load DC-DC module

integrating digital power conversion and intelligent power management. When used with ZM7000 Series Digital

Power Managers, the ZY7120 completely eliminates the need for external components for sequencing, tracking,

protection, monitoring, and reporting. All parameters of the ZY7120 are programmable via the industry-standard

I2C communication bus and can be changed by a user at any time during product development and service.

ZY7120 20A DC-DC Intelligent POL Data Sheet

3V to 13.2V Input  0.5V to 5.5V Output

ZD-00194 Rev. 2.5, 01-Jul-10 www.power-one.com Page 2 of 34

Reference Documents:

 ZM7XXX Digital Power Manager. Data Sheet

 ZM7XXX Digital Power Manager. Programming Manual

 Z-One® Graphical User Interface

 ZM00056-KIT USB to I2C Adapter Kit. User Manual

1. Ordering Information

ZY 71 20 x y – zz

Product

family:

Z-One

Module

Series:

Intelligent

POL

Converter

Output

Current:

20A

Output voltage setpoint

accuracy:

L – 1.2% or 20mV,

whichever is greater.

H1 – 1.0% or 10mV,

whichever is greater

RoHS compliance:

No suffix - RoHS

compliant with Pb

solder exemption2

G - RoHS compliant

for all six substances

Dash

Packaging Option3:

T1 – 500pcs T&R

T2 – 100pcs T&R

T3 – 50pcs T&R

Q1 – 1pc sample for

evaluation only

______________________________________

1 Contact factory for availability.

2 The solder exemption refers to all the restricted materials except lead in solder. These materials are Cadmium (Cd), Hexavalent chromium

(Cr6+), Mercury (Hg), Polybrominated biphenyls (PBB), Polybrominated diphenylethers (PBDE), and Lead (Pb) used anywhere except in

solder.

3 Packaging option is used only for ordering and not included in the part number printed on the POL converter label.

4 The evaluation board is available in only one configuration: ZM7300-KIT-HKS.

Example: ZY7120HG-T2: A 100-piece reel of RoHS compliant POL converters with the output voltage setpoint of

1.0% or 10mV, whichever is greater. Each POL converter is labeled ZY7120HG.

2. Absolute Maximum Ratings

Stresses in excess of the absolute maximum ratings may cause performance degradation, adversely affect long-

term reliability, and cause permanent damage to the converter.

Parameter Conditions/Description Min Max Units

Operating Temperature Controller case temperature -40 105 C

Input Voltage 250ms Transient 15 VDC

Output Current (See Output Current Derating Curves) -20 20 ADC

3. Environmental and Mechanical Specifications

Parameter Conditions/Description Min Nom Max Units

Ambient Temperature Range -40 85 C

Storage Temperature (Ts) -55 125 C

Weight 15 grams

MTBF Calculated Per Telcordia Technologies SR-332 6.14 MHrs

Peak Reflow Temperature ZY7120

ZY7120G

245

220

260

C

Lead Plating ZY7120 and ZY7120G 100% Matte Tin or

1.5µm Ag over 1.5µm Ni

Moisture Sensitivity Level ZY7120

ZY7120G

ZY7120 20A DC-DC Intelligent POL Data Sheet

3V to 13.2V Input  0.5V to 5.5V Output

ZD-00194 Rev. 2.5, 01-Jul-10 www.power-one.com Page 3 of 34

4. Electrical Specifications

Specifications apply at the input voltage from 3V to 13.2V, output load from 0 to 20A, ambient temperature from -

40°C to 85°C, 100F output capacitance, and default performance parameters settings unless otherwise noted.

4.1 Input Specifications

Parameter Conditions/Description Min Nom Max Units

Input voltage (VIN)

At VIN<4.75V, VLDO pin needs to be

connected to an external voltage source

higher than 4.75V

3 13.2 VDC

Input Current (at no load) VIN4.75V, VLDO pin connected to VIN 50 mADC

Undervoltage Lockout (VLDO

connected to VIN)

Ramping Up

Ramping Down 4.2

3.75 VDC

VDC

Undervoltage Lockout (VLDO

connected to VAUX=5V)

Ramping Up

Ramping Down 3.0

2.5 VDC

VDC

External Low Voltage Supply Connect to VLDO pin when VIN<4.75V 4.75 13.2 VDC

VLDO Input Current Current drawn from the external low

voltage supply at VLDO=5V 50 mADC

4.2 Output Specifications

Parameter Conditions/Description Min Nom Max Units

Output Voltage Range (VOUT) Programmable1

Default (no programming)

0.5

5.5

VDC

Output Voltage Setpoint Accuracy VIN=12V, IOUT=0.5*IOUT MAX,

FSW=500kHz, room temperature (See Ordering Information)

Output Current (IOUT) VIN MIN to VIN MAX -202 20 ADC

Line Regulation VIN MIN to VIN MAX ±0.3 %VOUT

Load Regulation 0 to IOUT MAX ±0.2 %VOUT

Dynamic Regulation

Peak Deviation

Settling Time

Slew rate 1A/



s, 50 -100% load step

COUT=330F, FSW=1MHz

to 10% of peak deviation

s

Output Voltage Peak-to-Peak

Ripple and Noise

BW=20MHz

Full Load

VIN=5.0V, VOUT=0.5V

VIN=5.0V, VOUT=2.5V

VIN=13.2V, VOUT=0.5V

VIN=13.2V, VOUT=2.5V

VIN=13.2V, VOUT=5.0V

Temperature Coefficient VIN=12V, IOUT=0.5*IOUT MAX 20 ppm/°C

Switching Frequency Default

Programmable, 250kHz steps

500

1,000

kHz

Duty Cycle Limit Default

Programmable, 1.56% steps

90.5

1 ZY7120 is a step-down converter, thus the output voltage is always lower than the input voltage as show in Figure 1.

2 At the negative output current (bus terminator mode) efficiency of the ZY7120 degrades resulting in increased internal power dissipation.

Therefore maximum allowable negative current under specific conditions is 20% lower than the current determined from the derating curves

shown in paragraph 5.5.

ZY7120 20A DC-DC Intelligent POL Data Sheet

3V to 13.2V Input  0.5V to 5.5V Output

ZD-00194 Rev. 2.5, 01-Jul-10 www.power-one.com Page 4 of 34

Figure 1. Output Voltage as a Function of Input Voltage and Output Current

4.3 Protection Specifications

Parameter Conditions/Description Min Nom Max Units

Output Overcurrent Protection

Type Default

Programmable

Non-Latching, 130ms period

Latching/Non-Latching

Threshold Default

Programmable in 11 steps

140

%IOUT

Threshold Accuracy -25 25 %IOCP.SET

Output Overvoltage Protection

Type Default

Programmable

Non-Latching, 130ms period

Latching/Non-Latching

Threshold Default

Programmable in 10% steps

1101 130

130

%VO.SET

Threshold Accuracy Measured at VO.SET=2.5V -2 2 %VOVP.SET

Delay From instant when threshold is exceeded until

the turn-off command is generated 6 μs

ZY7120 20A DC-DC Intelligent POL Data Sheet

3V to 13.2V Input  0.5V to 5.5V Output

ZD-00194 Rev. 2.5, 01-Jul-10 www.power-one.com Page 5 of 34

Output Undervoltage Protection

Type Default

Programmable

Non-Latching, 130ms period

Latching/Non-Latching

Threshold Default

Programmable in 5% steps

%VO.SET

Threshold Accuracy Measured at VO.SET=2.5V -2 2 %VUVP.SET

Delay From instant when threshold is exceeded until

the turn-off command is generated 6 μs

Overtemperature Prot ection

Type Default

Programmable

Non-Latching, 130ms period

Latching/Non-Latching

Turn Off Threshold Temperature is increasing 130 C

Turn On Threshold Temperature is decreasing after the module was

shut down by OTP 120 C

Threshold Accuracy -5 5 C

Delay From instant when threshold is exceeded until

the turn-off command is generated 6 μs

Tracking Protection (when Enabled)

Type Default

Programmable

Disabled

Latching/Non-Latching, 130ms period

Threshold Enabled during output voltage ramping up 250 mVDC

Threshold Accuracy -50 50 mVDC

Delay From instant when threshold is exceeded until

the turn-off command is generated 6 μs

Overtemperature W arning

Threshold Always enabled, reported in Status register 120 C

Threshold Accuracy -5 5 C

Hysteresis 3 C

Delay From instant when threshold is exceeded until

the warning signal is generated 6 μs

Power Good Signal (PGOOD pin)

Logic VOUT is inside the PG window

VOUT is outside the PG window

High

Low N/A

Lower Threshold Default

Programmable in 5% steps

%VO.SET

Upper Threshold 110 %VO.SET

Delay From instant when threshold is exceeded until

status of PG signal changes 6 μs

Threshold Accuracy Measured at VO.SET=2.5V -2 2 %VO.SET

___________________

1 Minimum OVP threshold is 1.0V

ZY7120 20A DC-DC Intelligent POL Data Sheet

3V to 13.2V Input  0.5V to 5.5V Output

ZD-00194 Rev. 2.5, 01-Jul-10 www.power-one.com Page 6 of 34

4.4 Feature Specifications

Parameter Conditions/Description Min Nom Max Units

Current Share

Type Active, Single Line

Maximum Number of Modules

Connected in Parallel IOUT MIN≥20%*IOUT NOM 10

Maximum Number of Modules

Connected in Parallel IOUT MIN=0 4

Current Share Accuracy IOUT MIN≥20%*IOUT NOM ±20 %IOUT

Interleave

Interleave (Phase Shift) Default

Programmable in 11.25 steps

348.75

Degree

degree

Sequencing

Turn ON Delay Default

Programmable in 1ms steps

255

Turn OFF Delay Default

Programmable in 1ms steps

Tracking

Turn ON Slew Rate Default

Programmable in 7 steps

0.1

8.331 V/ms

V/ms

Turn OFF Slew Rate Default

Programmable in 7 steps

-0.1

-8.331 V/ms

V/ms

Optimal Voltage Positioning

Load Regulation Default

Programmable in 7 steps

6.02

mV/A

Feedback Loop Compensation

Zero1 (Effects phase lead and

increases gain in mid-band) Programmable 0.05 50 kHz

Zero 2 (Effects phase lead and

increases gain in mid-band) Programmable 0.05 50 kHz

Pole 1 (Integrator Pole, effects

loop gain) Programmable 0.05 50 kHz

Pole 2 (Effects phase lag and

limits gain in mid-band) Programmable 1 1000 kHz

Pole 3 (High frequency low- pass

filter to limit PWM noise) Programmable 1 1000 kHz

Monitoring

Voltage Monitoring Accuracy 1 LSB=22mV -2%VOUT

– 1 LSB 2%VOUT

+ 1 LSB mV

Current Monitoring Accuracy 20%*IOUT NOM < IOUT < IOUT NOM -20 +20 %IOUT

Temperature Monitoring Accuracy Junction temperature of POL controller -5 +5 C

Remote Voltage Sense (+VS and –VS pins)

Voltage Drop Compensation Between +VS and VOUT 300 mV

Voltage Drop Compensation Between -VS and PGND 100 mV

___________________

1 Achieving fast slew rates under specific line and load conditions may require feedback loop adjustment

ZY7120 20A DC-DC Intelligent POL Data Sheet

3V to 13.2V Input  0.5V to 5.5V Output

ZD-00194 Rev. 2.5, 01-Jul-10 www.power-one.com Page 7 of 34

4.5 Signal Specifications

Parameter Conditions/Description Min Nom Max Units

VDD Internal supply voltage 3.15 3.3 3.45 V

SYNC/DATA Line (SD pin)

ViL_sd LOW level input voltage -0.5 0.3 x VDD V

ViH_sd HIGH level input voltage 0.75 x

VDD VDD + 0.5 V

Vhyst_sd Hysteresis of input Schmitt trigger 0.25 x

VDD 0.45 x

VDD V

VoL LOW level sink current @ 0.5V 14 60 mA

Tr_sd Maximum allowed rise time 10/90%VDD 300 ns

Cnode_sd Added node capacitance 5 10 pF

Ipu_sd Pull-up current source at Vsd=0V 0.3 1.0 mA

Freq_sd Clock frequency of external SD line 475 525 kHz

Tsynq Sync pulse duration 22 28 % of clock

cycle

T0 Data=0 pulse duration 72 78 % of clock

cycle

Inputs: ADDR0…ADDR4, EN, IM

ViL_x LOW level input voltage -0.5 0.3 x VDD V

ViH_x HIGH level input voltage 0.7 x VDD VDD+0.5 V

Vhyst_x Hysteresis of input Schmitt trigger 0.1 x VDD 0.3 x VDD V

RdnL_ADDR External pull down resistance

ADDRX forced low 10 kOhm

Power Good and OK Inputs/Outputs

Iup_PG Pull-up current source input forced low PG 25 110 μA

Iup_OK Pull-up current source input forced low OK 175 725 μA

ViL_x LOW level input voltage -0.5 0.3 x VDD V

ViH_x HIGH level input voltage 0.7 x VDD VDD+0.5 V

Vhyst_x Hysteresis of input Schmitt trigger 0.1 x VDD 0.3 x VDD V

IoL LOW level sink current at 0.5V 4 20 mA

Current Share Bus (CS pin)

Iup_CS Pull-up current source at VCS = 0V 0.84 3.1 mA

ViL_CS LOW level input voltage -0.5 0.3 x VDD V

ViH_CS HIGH level input voltage 0.75 x

VDD VDD+0.5 V

Vhyst_CS Hysteresis of input Schmitt trigger 0.25 x

VDD 0.45 x

VDD V

IoL LOW level sink current at 0.5V 14 60 mA

Tr_CS Maximum allowed rise time 10/90% VDD 100 ns

ZY7120 20A DC-DC Intelligent POL Data Sheet

3V to 13.2V Input  0.5V to 5.5V Output

ZD-00194 Rev. 2.5, 01-Jul-10 www.power-one.com Page 8 of 34

5. Typical Performance Characteristics

5.1 Efficiency Curves

02468101214161820

Output Current, A

Efficiency, %

Vout=0.5V Vout=1.2V Vout=2.5V

Figure 2. Efficiency vs. Load. Vin=3.3V, Fsw=500kHz

0 2 4 6 8 101214161820

Output Current, A

Efficiency, %

Vout=0.5V Vout=1.2V

Vout=2.5V Vout=3.3V

Figure 3. Efficiency vs. Load. Vin=5V, Fsw=500kHz

0 2 4 6 8 10 12 14 16 18 20

Output Current, A

Efficiency, %

Vout=1.2V Vout=2.5V

Vout=3.3V Vout=5.0V

Figure 4. Efficiency vs. Load. Vin=12V, Fsw=500kHz

0.5 1.5 2.5 3.5 4.5 5.5

Output Voltage, V

Efficiency, %

Vin=3.3V Vin=5.0V Vin= 12V

Figure 5. Efficiency vs. Output Voltage, Iout=20A,

Fsw=500kHz

ZY7120 20A DC-DC Intelligent POL Data Sheet

3V to 13.2V Input  0.5V to 5.5V Output

ZD-00194 Rev. 2.5, 01-Jul-10 www.power-one.com Page 9 of 34

3456789101112

Input Voltage, V

Efficiency, %

Vout=0.5V Vout=1.2V Vout=2.5V

Figure 6. Efficiency vs. Input Voltage. Iout=20A, Fsw=500kHz

0 2 4 6 8 101214161820

Output Current, A

Efficiency, %

Fsw=500kHz Fsw=750kHz Fsw=1,000kHz

Figure 7. Efficiency vs. Load. Vin=3.3V, Vout=2.5V

0 2 4 6 8 101214161820

Output Current, A

Efficiency, %

Fsw=500kHz Fsw=750kHz Fsw=1,000kHz

Figure 8. Efficiency vs. Load. Vin=5V, Vout=1.2V

02468101214161820

Output Current, A

Efficiency, %

Fsw=500kHz Fsw=750kHz Fsw=1,000kHz

Figure 9. Efficiency vs. Load. Vin=12V, Vout=5V

ZY7120 20A DC-DC Intelligent POL Data Sheet

3V to 13.2V Input  0.5V to 5.5V Output

ZD-00194 Rev. 2.5, 01-Jul-10 www.power-one.com Page 10 of 34

500 750 1000

Switching Frequency, kHz

Efficiency, %

Vin=3.3V, Vout=2.5V

Vin=5V, Vout=1.2V

Vin=12V, Vout=5V

Figure 10. Efficiency vs. Switching Frequency. Iout=20A

5.2 Turn-On Characteristics

Figure 11. Tracking Turn-On. Rising Slew Rate is

Programmed at 0.5V/ms.

Vin=12V, Ch1 – V1, Ch2 – V2, Ch3 – V3

Figure 12. Turn-On with Different Rising Slew Rates.

Rising Slew Rates are Programmed as follows: V1-

1V/ms, V2-0.5V/ms, V3-0.2V/ms.

Vin=12V, Ch1 – V1, Ch2 – V2, Ch3 – V3

Figure 13. Sequenced Turn-On. Rising Slew Rate is

Programmed at 1V/ms. V2 Delay is 2ms, V3 delay

is 4ms. Vin=12V, Ch1 – V1, Ch2 – V2, Ch3 – V3

ZY7120 20A DC-DC Intelligent POL Data Sheet

3V to 13.2V Input  0.5V to 5.5V Output

ZD-00194 Rev. 2.5, 01-Jul-10 www.power-one.com Page 11 of 34

Figure 14. Turn On with Sequencing and Tracking. Rising

Slew Rate Programmed at 0.2V/ms, V1 and V3

delays are programmed at 20ms.

Vin=12V, Ch1 – V1, Ch2 – V2, Ch3 – V3

Figure 15. Turn On into Prebiased Load. V3 is Prebiased by

V2 via a Diode.

Vin=12V, Ch1 – V1, Ch2 – V2, Ch3 – V3

5.3 Turn-Off Characteristics

Figure 16. Tracking Turn-Off. Falling Slew Rate is

Programmed at 0.5V/ms.

Vin=12V, Ch1 – V1, Ch2 – V2, Ch3 – V3

Figure 17. Turn-Off with Tracking and Sequencing. Falling

Slew Rate is Programmed at 0.5V/ms.

Vin=12V, Ch1 – V1, Ch2 – V2, Ch3 – V3

ZY7120 20A DC-DC Intelligent POL Data Sheet

3V to 13.2V Input  0.5V to 5.5V Output

ZD-00194 Rev. 2.5, 01-Jul-10 www.power-one.com Page 12 of 34

5.4 Transient Response

The pictures below show the deviation of the output

voltage in response to the 50-100-50% step load at

1A/μs. In all tests the ZY7120 converters were

switching at 1MHz and had 5x22μF and 5x47μF

ceramic capacitors connected across the output

pins. Bandwidth of the feedback loop was

programmed for faster transient response.

Figure 18. Vin=12V, Vout=5V, BW~40kHz

Figure 19. Vin=12V, Vout=1V, BW~35kHz

Figure 20. Vin=5V, Vout=2.5V, BW~45kHz

Figure 21. Vin=5V, Vout=1V, B W~40kHz

Figure 22. Vin=3.3V, Vout=1V, BW~40kHz

ZY7120 20A DC-DC Intelligent POL Data Sheet

3V to 13.2V Input  0.5V to 5.5V Output

ZD-00194 Rev. 2.5, 01-Jul-10 www.power-one.com Page 13 of 34

5.5 Thermal Derating Curves

35 45 55 65 75 85

Temperature , 'C

Output Curren t , A

0 LFM 100 LFM 200 LFM 400 LFM 600 LFM

Figure 23. Thermal Derating Curves. Vin=13.2V, Vout=5.0V, Fsw=500kHz

65 70 75 80 85

Temperature, 'C

Output Current, A

0 LFM 100 LFM 200 LFM 400 LFM 600 LFM

Figure 24. Thermal Derating Curves. Vin=5.0V, Vout=2.5V, Fsw =500kHz

ZY7120 20A DC-DC Intelligent POL Data Sheet

3V to 13.2V Input  0.5V to 5.5V Output

ZD-00194 Rev. 2.5, 01-Jul-10 www.power-one.com Page 14 of 34

6. Typical Application

ZY7120

V1 V2 V3

OK_A

OK_B

ADDR ADDR ADDR ADDR

DPM

Intermediate Voltage Bus

ZY7120 ZY7120 ZY7120

OK_C

Figure 25. Block Diagram of Typical Multiple Output Application with Digital Power Manager and I2C Interface

The block diagram of a typical application of ZY7120 point-of-load converters (POL) is shown in Figure 25. The

system includes multiple POLs and a ZM7000 series Digital Power Manager (DPM). All POLs are connected to

the DPM and to each other via a single-wire SD (sync/data) line. The line provides synchronization of all POLs to

the master clock generated by the DPM and simultaneously performs bidirectional data transfer between POLs

and the DPM. Each POL has a unique 5-bit address programmed by grounding respective address pins. To

enable the current share, CS pins of POLs connected in parallel are linked together.

There are three groups of POLs in the application, groups A, B, and group C. A group is defined as a number of

POLs interconnected via OK pins. Grouping of POLs enables users to program, control, and monitor multiple

POLs simultaneously and execute advanced fault management schemes.

The complete schematic of the application is shown in Figure 26.

ZY7120 20A DC-DC Intelligent POL Data Sheet

3V to 13.2V Input  0.5V to 5.5V Output

ZD-00194 Rev. 2.5, 01-Jul-10 www.power-one.com Page 15 of 34

Figure 26. Complete Schema tic of the Application Shown in Figure 25. Intermediate Bus Voltage is from 4.75V to 13.2V.

ZY7120 20A DC-DC Intelligent POL Data Sheet

3V to 13.2V Input  0.5V to 5.5V Output

ZD-00194 Rev. 2.5, 01-Jul-10 www.power-one.com Page 16 of 34

7. Pin Assignments a nd Description

Name Pin

Number Pin

Type Buffer

Type Pin Description Notes

VLDO 1 P Low Voltage Dropout Connect to an external voltage source higher than

4.75V, if VIN<4.75V. Connect to VIN, if VIN≥4.75V

IM 2 Not Used Leave floating

NC 3 Not Used Leave floating

NC 4 Not Used Leave floating

NC 5 Not Used Leave floating

NC 6 Not Used Leave floating

NC 7 Not Used Leave floating

NC 8 Not Used Leave floating

VREF 9 Not Used Leave floating

EN 10 Connect to PGND Connect to PGND

OK 11 I/O PU Fault/Status Condition

Connect to OK pin of other Z-POL and/or DPM.

Leave floating, if not used

SD 12 I/O PU Sync/Data Line Connect to SD pin of DPM

PGOOD 13 I/O PU Power Good

TRIM 14 Not Used Leave floating

CS 15 I/O PU Current Share Connect to CS pin of other Z-POLs connected in

parallel

ADDR4 16 I PU POL Address Bit 4 Tie to PGND for 0 or leave floating for 1

ADDR3 17 I PU POL Address Bit 3 Tie to PGND for 0 or leave floating for 1

ADDR2 18 I PU POL Address Bit 2 Tie to PGND for 0 or leave floating for 1

ADDR1 19 I PU POL Address Bit 1 Tie to PGND for 0 or leave floating for 1

ADDR0 20 I PU POL Address Bit 0 Tie to PGND for 0 or leave floating for 1

-VS 21 I PU Negative Voltage Sense Connect to the negative point close to the load

+VS 22 I PU Positive Voltage Sense Connect to the positive point close to the load

VOUT 23 P Output Voltage

PGND 24 P Power Ground

VIN 25 P Input Voltage

Legend: I=input, O=output, I/O=input/output, P=power, A=analog, PU=internal pull-up

ZY7120 20A DC-DC Intelligent POL Data Sheet

3V to 13.2V Input  0.5V to 5.5V Output

ZD-00194 Rev. 2.5, 01-Jul-10 www.power-one.com Page 17 of 34

8. Programmable Features

Performance parameters of ZY7120 POL converters

can be programmed via the industry standard I2C

communication bus without replacing any

components or rewiring PCB traces. Each

parameter has a default value stored in the volatile

memory registers detailed in Table 1. The setup

registers 00h through 14h are programmed at the

system power-up. When the user programs new

performance parameters, the values in the registers

are overwritten. Upon removal of the input voltage,

the default values are restored.

Table 1. ZY7120 Memory Registers

PC1 Protection Configuration 1 00h

PC2 Protection Configuration 2 01h

PC3 Protection Configuration 3 02h

DON Turn-On Delay 05h

DOF Turn-Off Delay 06h

TC Tracking Configuration 03h

INT Interleave Configuration and

Frequency Selection

04h

RUN RUN Register 15h

ST Status Register 16h

VOS Output Voltage Setpoint 07h

CLS Current Limit Setpoint 08h

DCL Duty Cycle Limit 09h

B1 Dig Controller Denominator z-

Coefficient

0Ah

B2 Dig Controller Denominator z-

Coefficient

0Bh

B3 Dig Controller Denominator z-

Coefficient

0Ch

C0L Dig Controller Numerator z

Coefficient, Low Byte

0Dh

C0H Dig Controller Numerator z

Coefficient, High Byte

0Eh

C1L Dig Controller Numerator z-

Coefficient, Low Byte

0Fh

C1H Dig Controller Numerator z-

Coefficient, High Byte

10h

C2L Dig Controller Numerator z-

Coefficient, Low Byte

11h

C2H Dig Controller Numerator z-

Coefficient, High Byte

12h

C3L Dig Controller Numerator z-

Coefficient, High Byte

13h

C3H Dig Controller Numerator z-

Coefficient, Low Byte

14h

VOM Output Voltage Monitoring 17h

IOM Output Current Monitoring 18h

TMP Temperature Monitoring 19h

ZY7120 converters can be programmed using the

Graphical User Interface or directly via the I2C bus by

using high and low level commands as described in

the ‘”DPM Programming Manual”.

ZY7120 parameters can be reprogrammed at any

time during the system operation and service except

for the digital filter coefficients, the switching

frequency and the duty cycle limit, that can only be

changed when the POL is turned off.

8.1 Output Voltage

The output voltage can be programmed in the GUI

Output Configuration window shown in the Figure 27

or directly via the I2C bus by writing into the VOS

Figure 27. Output Configuration Window

VOS7 VOS6 VOS5 VOS4 VOS2 VOS1 VOS0

Bit 7 Bit 0

R = Readable bit

W = Writable bit

U = Unimplemented bit,

read as ‘0’

- n = Value at POR reset

R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0

R/W-0

Bit 7:0

OS[7:0], Output voltage setting

00h: corresponds to 0.5000V

01h: corresponds to 0.5125V

…

77h: corresponds to 1.9875V

78h: corresponds to 2.0000V

79h: corresponds to 2.025V

…

F9h: corresponds to 5.225V

FAh: corresponds to 5.250V

FBh: corresponds to 5.300V

…

FFh: corresponds to 5.500V

VOS3

Figure 28. Output Voltage Setpoint Register VOS

ZY7120 20A DC-DC Intelligent POL Data Sheet

3V to 13.2V Input  0.5V to 5.5V Output

ZD-00194 Rev. 2.5, 01-Jul-10 www.power-one.com Page 18 of 34

8.1.1 Output Voltage Setpoint

The output voltage programming range is from 0.5V

to 5.5V. Within this range, there are 256 predefined

voltage setpoints. To improve resolution of the

output voltage settings, the voltage range is divided

into three sub-ranges as shown in Table 2.

Table 2. Output Voltage Adjustment Resolution

VOUT MIN, V VOUT MAX, V Resolution, mV

0.500 2.000 12.5

2.025 5.25 25

5.3 5.5 50

8.1.2 Output Voltage Margining

If the output voltage needs to be varied by a certain

percentage, the margining function can be utilized.

The margining can be programmed in the GUI

Output Configuration window or directly via the I2C

bus using high level commands as described in the

‘”DPM Programming Manual”.

In order to properly margin POLs that are connected

in parallel, the POLs must be members of one of the

Parallel Buses. Refer to the GUI System

Configuration Window shown in Figure 55.

8.1.3 Optimal Voltage Positioning

Optimal voltage positioning increases the voltage

regulation window by properly positioning the output

voltage setpoint. Positioning is determined by the

load regulation that can be programmed in the GUI

Output Configuration window shown in Figure 27 or

directly via the I2C bus by writing into the CLS

Figure 29 illustrates optimal voltage positioning

concept. If no load regulation is programmed, the

headroom (voltage differential between the output

voltage setpoint and a regulation limit) is

approximately half of the voltage regulation window.

When load regulation is programmed, the output

voltage will decrease as the output current

increases, so the VI characteristic will have a

negative slope. Therefore, by properly selecting the

operating point, it is possible to increase the

headroom as shown in the picture.

Upper Regulation

Limit

Lower Regulation

Limit

Light

Load

VOUT

IOUT

I C urve With ou t

Load Regulation

I Curve With

Load Regulation

Heavy

Load

Headroom without

Load Regulation

Operating

Point

Headroom with

Load Regulation

Figure 29. Concept of Optimal Voltage Positioning

Increased headroom allows tolerating larger voltage

deviations. For example, the step load change from

light to heavy load will cause the output voltage to

drop. If the optimal voltage positioning is utilized, the

output voltage will stay within the regulation window.

Otherwise, the output voltage will drop below the

lower regulation limit. To compensate for the voltage

drop external output capacitance will need to be

added, thus increasing cost and complexity of the

system.

The effect of optimal voltage positioning is shown in

Figure 30 and Figure 31. In this case, switching

output load causes large peak-to-peak deviation of

the output voltage. By programming load regulation,

the peak to peak deviation is dramatically reduced.

Figure 30. Transient Response without Optimal Voltage

Positioning

ZY7120 20A DC-DC Intelligent POL Data Sheet

3V to 13.2V Input  0.5V to 5.5V Output

ZD-00194 Rev. 2.5, 01-Jul-10 www.power-one.com Page 19 of 34

Figure 31. Transient Response with Optimal Voltage

Positioning

8.2 Sequencing and Tracking

Turn-on delay, turn-off delay, and rising and falling

output voltage slew rates can be programmed in the

GUI Sequencing/Tracking window shown in Figure

32 or directly via the I2C bus by writing into the DON,

DOF, and TC registers, respectively. The registers

are shown in Figure 33, Figure 34, and Figure 36.

Figure 32. Sequencing/Tracking Window

8.2.1 Turn-On Delay

Turn-on delay is defined as an interval from the

application of the Turn-On command until the output

voltage starts ramping up.

DON7 DON6 DON5 DON4 DON2 DON1 DON0

Bit 7 Bit 0

R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0

R/W-0

Bit 7:0 DON[7:0]: Turn-on delay time

00h: corresponds to 0ms delay after turn-on command has occurred

…

FFh: corresponds to 255ms delay after turn-on command has occurred

DON3

Figure 33. Turn-On Delay Register DON

8.2.2 Turn-Off Delay

--- --- DOF5 DOF4 DOF2 DOF1 DOF0

Bit 7 Bit 0

U U R/W-0 R/W-0 R/W-0 R/W-0 R/W-0

R/W-0

Bit 7:6 Unimplemented, read as ‘0’

Bit 5:0 DOF[5:0]: Turn-off delay time

00h: corresponds to 0ms delay after turn-off command has occurred

…

3Fh: corresponds to 63ms delay after turn-off command has occurred

DOF3

Figure 34. Turn-Off Delay Register DOF

Turn-off delay is defined as an interval from the

application of the Turn-Off command until the output

voltage reaches zero (if the falling slew rate is

programmed) or until both high side and low side

switches are turned off (if the slew rate is not

programmed). Therefore, for the slew rate controlled

turn-off the ramp-down time is included in the turn-off

delay as shown in Figure 35.

Turn-Off

Command

Internal

ramp-down

command

VOUT

User programmed turn-off delay, TDF

Calculated

delay TD

Time

Ramp-down time, TF

Falling slew

rate dVF/dT

Figure 35. Relationship between Turn-Off Delay and Falling

Slew Rate

As it can be seen from the figure, the internally

calculated delay TD is determined by the equation

below.

TT F

OUT

DFD  ,

For proper operation TD shall be greater than zero.

The appropriate value of the turn-off delay needs to

be programmed to satisfy the condition.

ZY7120 20A DC-DC Intelligent POL Data Sheet

3V to 13.2V Input  0.5V to 5.5V Output

ZD-00194 Rev. 2.5, 01-Jul-10 www.power-one.com Page 20 of 34

If the falling slew rate control is not utilized, the turn-

off delay only determines an interval from the

application of the Turn-Off command until both high

side and low side switches are turned off. In this

case, the output voltage ramp-down process is

determined by load parameters.

8.2.3 Rising and Falling Slew Rates

The output voltage tracking is accomplished by

programming the rising and falling slew rates of the

output voltage. To achieve programmed slew rates,

the output voltage is being changed in 12.5mV steps

where duration of each step determines the slew

rate. For example, ramping up a 1.0V output with a

slew rate of 0.5V/ms will require 80 steps duration of

25μs each.

Duration of each voltage step is calculated by

dividing the master clock frequency generated by the

DPM. Since all POLs in the system are

synchronized to the master clock, the matching of

voltage slew rates of different outputs is very

accurate as it can be seen in Figure 11 and Figure

16.

During the turn on process, a POL not only delivers

current required by the load (ILOAD), but also charges

the load capacitance. The charging current can be

determined from the equation below:

CI R

LOADCHG 

Where, CLOAD is load capacitance, dVR/dt is rising

voltage slew rate, and ICHG is charging current.

When selecting the rising slew rate, a user needs to

ensure that

OCPCHGLOAD III 

Where IOCP is the overcurrent protection threshold of

the ZY7120. If the condition is not met, then the

overcurrent protection will be triggered during the

turn-on process. To avoid this, dVR/dt and the

overcurrent protection threshold should be

programmed to meet the condition above.

Figure 36. Tracking Configuration Register TC

8.3 Protections

ZY7120 Series converters have a comprehensive set

of programmable protections. The set includes the

output over- and undervoltage protections,

overcurrent protection, overtemperature protection,

tracking protection, overtemperature warning, and

Power Good signal. Status of protections is stored in

the ST register shown in Figure 37.

Figure 37. Protection Status Register ST

Thresholds of overcurrent, over- and undervoltage

protections, and Power Good limits can be

programmed in the GUI Output Configuration

window or directly via the I2C bus by writing into the

CLS and PC2 registers shown in Figure 38 and

Figure 39.

--- R2 R1 R0 F2 F1 F0

Bit 7 Bit 0

R = Readable bit

W = Writable bit

U = Unimplemented bit,

read as ‘0’

-n =Value at POR reset

UR/W-0R/W-0 R/W-0 R/W-0 R/W-0 R/W-0

R/W-1

Bit 7 Unimplemented , read as ‘0’

Bit 6:4 R[2:0]: Value of Vo rising slope

0: corresponds to 0.1V/ms (default)

1: corresponds to 0.2V/ms

2: corresponds to 0.5V/ms

3: corresponds to 1.0V/ms

4: corresponds to 2.0V/ms

5: corresponds to 5.0V/ms

6: corresponds to 8.3V/ms

7: corresponds to 8.3V/ms

Bit 3 SC, Slew rate control at turn-of

0: Slew rate control is disabled

1: Slew rate control is enabled

Bit 2:0 F[2:0]: Value of Vo falling slope

0: corresponds to -0.1V/ms (default)

1: corresponds to -0.2V/ms

2: corresponds to -0.5V/ms

3: corresponds to -1.0V/ms

4: corresponds to -2.0V/ms

5: corresponds to -5.0V/ms

6: corresponds to –8.3V/ms

7: corresponds to –8.3V/ms

TP PG TR OT UV OV PV

Bit 7 Bit 0

R=Readable bi

W = Writable bit

U=Unimplemented bit,

read as ‘0’

-n =Value at POR rese

R-1 R-0 R-1 R-1 R-1 R-1 R-1

R-1

Bit 7 TP: Temperature Warning

Bit 6 PG: Power Good Warning

Bit 5 TR: Tracking Fault

Bit 4 OT: Overtemperature Fault

Bit 3 OC: Overcurrent Fault

Bit 2 UV: Undervoltage Fault

Bit 1 O

: Overvoltage Error

Bit 0 P

: Phase Voltage Erro

Note:

- An activated warning/fault/error is encoded as ‘0’

ZY7120 20A DC-DC Intelligent POL Data Sheet

3V to 13.2V Input  0.5V to 5.5V Output

ZD-00194 Rev. 2.5, 01-Jul-10 www.power-one.com Page 21 of 34

LR2 LR1 LR0 TCE CLS2 CLS1 CLS0

Bit 7 Bit 0

R = Readable bit

W = Writable bit

U = Unimplemented bit,

read as ‘0’

- n = Value at POR reset

R/W-0 R/W-0 R/W-0 R/W-1 R/W-0 R/W-1 R/W-1

R/W-1

Bit 7:5 LR[2:0], Load regulation configuration

000: 0 V/A/Ohm

001: 0.39 V/A/Ohm

010: 0.78 V/A/Ohm

011: 1.18 V/A/Ohm

100: 1.57 V/A/Ohm

101: 1.96 V/A/Ohm

110: 2.35 V/A/Ohm

111: 2.75 V/A/Ohm

Bit 4 TCE, Temperature compensation enable

0: disabled

1: enabled

Bit 3:0 CLS[3:0], Current limit setting

0h: corresponds to 37%

1h: corresponds to 47%

…

Bh: corresponds to 140%

Values higher than Bh are translated to Bh (140%)

CLS3

Figure 38. Current Limit Setpoint Register CLS

--- --- --- PGLL OVPL0 UVPL1 UVPL0

Bit 7 Bit 0

R = Readable bit

W = Writable bit

U = Unimplemented bit,

read as ‘0’

- n = Value at POR reset

U U U R/W-0 R/W-0 R/W-0 R/W-0

R/W-1

Bit 7:5 Unimplemented, read as ‘0’

Bit 4 PGLL: Set Power Good Low Level

1 = 95% of Vo

0 = 90% of Vo (Default)

Bit 3:2 OVPL[1:0]: Set Over Voltage Protection

Level

00 = 110% of Vo

01 = 120% of Vo

10 = 130% of Vo (Default)

11 = 130% of Vo

Bit 1:0 UVPL[1:0]: Set Under Voltage Protection Level

00 = 75% of Vo (Default)

01 = 80% of Vo

10 = 85% of Vo

OVPL1

Figure 39. Protection Co nfiguration Register PC2

Note that the overvoltage and undervoltage

protection thresholds and Power Good limits are

defined as percentages of the output voltage.

Therefore, the absolute levels of the thresholds

change when the output voltage setpoint is changed

either by output voltage adjustment or by margining.

In addition, a user can change type of protections

(latching or non-latching) or disable certain

protections. These settings are programmed in the

GUI Fault Management window shown in Figure 40

or directly via the I2C by writing into the PC1 register

shown in Figure 41.

Figure 40. Fault Management Window

Figure 41. Protection Co nfiguration Register PC1

If the non-latching protection is selected, a POL will

attempt to restart every 130ms until the condition

that triggered the protection is removed. When

restarting, the output voltages follow tracking and

sequencing settings.

If the latching type is selected, a POL will turn off and

stay off. The POL can be turned on after 130ms, if

the condition that caused the fault is removed and

the respective bit in the ST register was cleared, or

the Turn On command was recycled, or the input

voltage was recycled.

TRE PVE TRP OTP UVP OVP PVP

Bit 7 Bit 0

R = Readable bit

W = Writable bit

U = Unimplemented bit,

read as ‘0’

-n =Value at POR rese

R/W-0 R/W-1 R/W-0 R/W-0 R/W-0 R/W-1 R/W-1

R/W-0

Bit 7 TRE: Tracking fault enable

1 = enabled

0 = disabled

Bit 6 PVE: Phase voltage error enable

1 = enabled

0 = disabled

Bit 5 TRP: Tracking fault protection

1 = latching

0 = non latching

Bit 4 OTP: Overtemperature protection configuration

1 = latching

0 = non latching

Bit 3 OCP: Overcurrent protection configuration

1 = latching

0 = non latching

Bit 2 UVP: Undervoltage protection configuration

1 = latching

0 = non latching

Bit 1 OVP: Overvoltage protection configuration

1 = latching

0 = non latching

Bit 0 PVP: Phase Voltage Protection

1 = latching

0 = non latching

OCP

ZY7120 20A DC-DC Intelligent POL Data Sheet

3V to 13.2V Input  0.5V to 5.5V Output

ZD-00194 Rev. 2.5, 01-Jul-10 www.power-one.com Page 22 of 34

All protections can be classified into three groups

based on their effect on system operation: warnings,

faults, and errors.

8.3.1 Warnings

This group includes Overtemperature Warning and

Power Good Signal. The warnings do not turn off

POLs but rather generate signals that can be

transmitted to a host controller via the I2C bus.

8.3.1.1 Overtemperature Warning

The Overtemperature Warning is generated when

temperature of the controller exceeds 120°C. The

Overtemperature Warning changes the PT bit of the

status register ST to 0 and sends the signal to the

DPM. Reporting is enabled in the GUI Fault

Management window or directly via the I2C by writing

into the PC3 register shown in Figure 43. When the

temperature falls below 117°C, the PT bit is cleared

and the Overtemperature Warning is removed.

8.3.1.2 Power Good

Power Good is an open collector output that is pulled

low, if the output voltage is outside of the Power

Good window. The window is formed by the Power

Good High threshold that is equal to 110% of the

output voltage and the Power Good Low threshold

that can be programmed at 90 or 95% of the output

voltage.

The Power Good protection is only enabled after the

output voltage reaches its steady state level. The

PGOOD pin is pulled low during transitions of the

output voltage from one level to other as shown in

Figure 42.

The Power Good Warning pulls the Power Good pin

low and changes the PG bit of the status register ST

to 0. It sends the signal to the DPM, if the reporting

is enabled. When the output voltage returns within

the Power Good window, the PG pin is pulled high,

the PG bit is cleared and the Power Good Warning is

removed. The Power Good pin can also be pulled

low by an external circuit to initiate the Power Good

Warning.

Note: To retrieve status information, Status Monitoring in the GUI

POL Group Configuration Window should be enabled (refer

to Digital Power Manager Data Sheet). The DPM will

retrieve the status information from each POL on a

continuous basis.

8.3.2 Faults

This group includes overcurrent, overtemperature,

undervoltage, and tracking protections. Triggering

any protection in this group will turn off the POL.

8.3.2.1 Overcurrent Protection

Overcurrent protection is active whenever the output

voltage of the POL exceeds the prebias voltage (if

any). When the output current reaches the OC

threshold, the output voltage will start decreasing.

As soon as the output voltage decreases below the

undervoltage protection threshold, the OC fault

signal is generated, the POL turns off and the OC bit

in the register ST is changed to 0. Both high side

and low side switches of the POL are turned off

instantly (fast turn-off).

The temperature compensation is added to keep the

OC threshold approximately constant at

temperatures above room temperature. Note that

the temperature compensation can be disabled in

the GUI Output Configuration window or directly via

the I2C by writing into the CLS register. However, it

is recommended to keep the temperature

compensation enabled.

8.3.2.2 Undervoltage Protection

The undervoltage protection is only active during

steady state operation of the POL to prevent

nuisance tripping. If the output voltage decreases

below the UV threshold and there is no OC fault, the

UV fault signal is generated, the POL turns off, and

the UV bit in the register ST is changed to 0. The

output voltage is ramped down according to

sequencing and tracking settings (regular turn-off).

8.3.2.3 Overtemperature Protection

Overtemperature protection is active whenever the

POL is powered up. If temperature of the controller

exceeds 130°C, the OT fault is generated, POL turns

off, and the OT bit in the register ST is changed to 0.

The output voltage is ramped down according to

sequencing and tracking settings (regular turn-off).

If non-latching OTP is programmed, the POL will

restart as soon as the temperature of the controller

decreases below the Overtemperature Warning

threshold of 120°C.

ZY7120 20A DC-DC Intelligent POL Data Sheet

3V to 13.2V Input  0.5V to 5.5V Output

ZD-00194 Rev. 2.5, 01-Jul-10 www.power-one.com Page 23 of 34

8.3.2.4 Tracking Protection

Tracking protection is active only when the output

voltage is ramping up. The purpose of the protection

is to ensure that the voltage differential between

multiple rails being tracked does not exceed 250mV.

This protection eliminates the need for external

clamping diodes between different voltage rails

which are frequently recommended by ASIC

manufacturers.

When the tracking protection is enabled, the POL

continuously compares actual value of the output

voltage to its programmed value as defined by the

output voltage and its rising slew rate. If absolute

value of the difference exceeds 250mV, the tracking

fault signal is generated, the POL turns off, and the

TR bit in the register ST is changed to 0. Both high

side and low side switches of the POL are turned off

instantly (fast turn-off).

The tracking protection can be disabled, if it

contradicts requirements of a particular system (for

example turning into high capacitive load where

rising slew rate is not important). It can be disabled

in the GUI Fault Management window or directly via

the I2C bus by writing into the PC1 register.

Figure 42. Protections Enable Conditions

8.3.3 Errors

The group includes overvoltage protection and the

phase voltage error. The phase voltage error is not

available in ZY7120.

8.3.3.1 Overvoltage Protection

The overvoltage protection is active whenever the

output voltage of the POL exceeds the pre-bias

voltage (if any). If the output voltage exceeds the

overvoltage protection threshold, the overvoltage

error signal is generated, the POL turns off, and the

OV bit in the register ST is changed to 0. The high

side switch is turned off instantly, and simultaneously

the low side switch is turned on to ensure reliable

protection of sensitive loads. The low side switch

provides low impedance path to quickly dissipate

energy stored in the output filter and achieve

effective voltage limitation.

The OV threshold can be programmed from 110% to

130% of the output voltage setpoint, but not lower

than 1.0V.

8.3.4 Faults and Errors Propagation

The feature adds flexibility to the fault management

scheme by giving users control over propagation of

fault signals within and outside of the system. The

propagation means that a fault in one POL can be

programmed to turn off other POLs and devices in

the system, even if they are not directly affected by

the fault.

OVP Threshold

Out

ut Volta

Time

1.0

Enable command 0

OCP enabled 0

prebiased output

OTP continuousl

enabled

OVP Threshold

P Threshold

UVP Threshold UVP Threshold

PG Low Threshold

PG Low Threshold PG High=110%VOUT

PG High=110%VOUT PG High=110%VOUT

Out

ut Volta

Out

ut Volta

Power Good

Signal 1

Tracking

Thresholds

ZY7120 20A DC-DC Intelligent POL Data Sheet

3V to 13.2V Input  0.5V to 5.5V Output

ZD-00194 Rev. 2.5, 01-Jul-10 www.power-one.com Page 24 of 34

8.3.4.1 Grouping of POLs

Z-Series POLs can be arranged in several groups to

simplify fault management. A group of POLs is

defined as a number of POLs with interconnected

OK pins. A group can include from 1 to 32 POLs. If

fault propagation within a group is desired, the

propagation bit needs to be checked in the GUI Fault

Management Window. The parameters can also be

programmed directly via the I2C bus by writing into

the PC3 register shown in Figure 43.

When propagation is enabled, the faulty POL pulls its

OK pin low. A low OK line initiates turn-off of other

POLs in the group.

Figure 43. Protection Co nfiguration Register PC3

In addition, the OK lines can be connected to the

DPM to facilitate propagation of faults and errors

between groups. One DPM can control up to 4

independent groups. To enable fault propagation

between groups, the respective bit needs to be

checked in the GUI Fault and Error Propagation

window shown in Figure 44.

Figure 44. Fault and Error Propagation Window

In this case low OK line will signal DPM to pull other

OK lines low to initiate shutdown of other POLs as

programmed in the GUI Fault and Error Propagation

window. If an error is propagated, the DPM can also

generate commands to turn off a front end (a DC-DC

converter generating the intermediate bus voltage)

and trigger an optional crowbar protection to

accelerate removal of the IBV voltage.

8.3.4.2 Propagation Process

Propagation of a fault (OCP, UVP, OTP, and TRP)

initiates regular turn-off of other POLs. The faulty

POL in this case performs either the regular or the

fast turn-off depending on a specific fault as

described in section 8.3.2.

Propagation of an error initiates fast turn-off of other

POLs. The faulty POL performs the fast turn-off and

turns on its low side switch.

Example of the fault propagation is shown in Figure

45 - Figure 46. In this three-output system (refer to

the block diagram in Figure 25), the POL powering

the output V3 (Ch 1 in the picture) encounters the

undervoltage fault after the turn-on. When the fault

propagation is not enabled, the POL turns off and

generates the UV fault signal. Because the UV fault

triggers the regular turn off, the POL meets its turn-

off delay and falling slew rate settings during the

turn-ff process as shown in Figure 45. Since the UV

fault is programmed to be non-latching, the POL will

attempt to restart every 130ms, repeating the

process described above until the condition causing

the undervoltage is removed.

If the fault propagation between groups is enabled,

the POL powering the output V3 pulls its OK line low

and the DPM propagates the signal to the POL

powering the output V1 that belongs to other group.

PTM PGM TRP OTP UVP OVP PVP

Bit 7 Bit 0

R = Readable bit

W = Writable bit

U = Unimplemented bit,

read as ‘0’

-n = Value at POR rese

R/W-0 R/W-0 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1

R/W-1

Bit 7 PTM: Temperature warning Message

1 = enabled

0 = disabled

Bit 6 PGM: Power good message

1 = enabled

0 = disabled

Bit 5 TRP

: Tracking fault propagation

1 = enabled

0 = disabled

Bit 4 OTP: Overtemperature fault propagation

1 = enabled

0 = disabled

Bit 3 OCP: Overcurrent fault propagation

1 = enabled

0 = disabled

Bit 2 UVP: Undervoltage fault propagation

1 = enabled

0 = disabled

Bit 1 OVP: Overvoltage error propagation

1 = enabled

0 = disabled

Bit 0 PVP

: Phase voltage error propagation

1 = enabled

0 = disabled

OCP

ZY7120 20A DC-DC Intelligent POL Data Sheet

3V to 13.2V Input  0.5V to 5.5V Output

ZD-00194 Rev. 2.5, 01-Jul-10 www.power-one.com Page 25 of 34

The POL powering the output V1 (Ch3 in the picture)

executes the regular turn-off. Since both V1 and V3

have the same delay and slew rate settings they will

continue to turn off and on synchronously every

130ms as shown in Figure 46 until the condition

causing the undervoltage is removed. The POL

powering the output V2 continues to ramp up until it

reaches its steady state level.

130ms is the interval from the instant of time when

the output voltage ramps down to zero until the

output voltage starts to ramp up again. Therefore,

the 130ms hiccup interval is guaranteed regardless

of the turn-off delay setting.

Figure 45. Turn-On into UVP on V3. The UV Fault Is

Programmed To Be Non- Latching. Ch1 – V3

(Group C), Ch2 – V2, Ch3 – V1 (Group A)

Figure 46. Turn-On into UVP on V3. The UV Fault Is

Programmed To Be Non-Latching and Propagate

From Group C to Group A. Ch1 – V3 (Group C),

Ch2 – V2, Ch3 – V1 (Group A)

Summary of protections, their parameters and

features are shown in Table 3

Table 3. Summary of Protections Parameters and Features

Code Name Type When Active Turn

Off Low Side

Switch Propagation Disable

PT Temperature

Warning

Warning Whenever VIN is applied No N/A Sends signal to

DPM

PG Power Good Warning During steady state No N/A Sends signal to

DPM

TR Tracking Fault During ramp up Fast Off Regular turn off Yes

OT Overtemperature Fault Whenever VIN is applied Regular Off Regular turn off No

OC Overcurrent Fault When VOUT exceeds prebias Fast Off Regular turn off No

UV Undervoltage Fault During steady state Regular Off Regular turn off No

OV Overvoltage Error When VOUT exceeds prebias Fast On Fast turn off No

ZY7120 20A DC-DC Intelligent POL Data Sheet

3V to 13.2V Input  0.5V to 5.5V Output

ZD-00194 Rev. 2.5, 01-Jul-10 www.power-one.com Page 26 of 34

8.4 PWM Parameters

Z-Series POLs utilize the digital PWM controller.

The controller enables users to program most of the

PWM performance parameters, such as switching

frequency, interleave, duty cycle, and feedback loop

compensation.

8.4.1 Switching Frequency

The switching frequency can be programmed in the

GUI PWM Controller window shown in Figure 47 or

directly via the I2C bus by writing into the INT register

shown in Figure 48. Note that the content of the

turned off.

Switching actions of all POLs connected to the SD

line are synchronized to the master clock generated

by the DPM. Each POL is equipped with a PLL and

a frequency divider so they can operate at multiples

(including fractional) of the master clock frequency

as programmed by a user. The POL converters can

operate at 500 kHz, 750 kHz, and 1 MHz. Although

synchronized, switching frequencies of different

POLs are independent of each other. It is

permissible to mix POLs operating at different

frequencies in one system. It allows optimizing

efficiency and transient response of each POL in the

system individually.

Figure 47. PWM Controller Window

Figure 48. Interleave Configuration Register INT

8.4.2 Interleave

Interleave is defined as a phase delay between the

synchronizing slope of the master clock on the SD

pin and PWM signal of a POL. The interleave can

be programmed in the GUI PWM Controller window

or directly via the I2C bus by writing into the INT

Every POL generates switching noise. If no

interleave is programmed, all POLs in the system

switch simultaneously and noise reflected to the

input source from all POLs is added together as

shown in Figure 49.

Figure 49. Input Voltage Noise, No Interleave

FRQ2 FRQ1 FRQ0 INT4 INT2 INT1 INT0

Bit 7 Bit 0

R=Readable bi

W = Writable bit

U=Unimplemented bit,

read as ‘0’

-n =Value at POR rese

R/W-0 R/W-0 R/W-0 R/W-0

1) R/W-01) R/W-01) R/W-0 1)

R/W-01)

Bit 7:5 FRQ[2:0]: PWM Frequency Selection

000: 500kHz

001: 750kHz

010: 1000lHz

011: 1250kHz

100: 1250kHz

101: 1500kHz

110: 1750kHz

111: 2000kHz

Bit 4:0 INT[4:0]: Interleave position

00h: Ton starts with 0.0° Phase lag to SD Line

01h: Ton starts wi th 11.25° Phase lag to SD Line

02h: Ton starts with 22.50° Phase lag to SD Line

…

1Fh: Ton starts with 348.75° Phase lag to SD Line

1) Initial value depends on the state of the Interleave Mode ( IM) Input:

IM=Open:

t POR reset the 5 corresponding ADDRESS bits are loaded

IM=Low:

t POR reset a 0 is loaded

INT3

ZY7120 20A DC-DC Intelligent POL Data Sheet

3V to 13.2V Input  0.5V to 5.5V Output

ZD-00194 Rev. 2.5, 01-Jul-10 www.power-one.com Page 27 of 34

Figure 50 shows the input voltage noise of the three-

output system with programmed interleave. Instead

of all three POLs switching at the same time as in

the previous example, the POLs V1, V2, and V3

switch at 67.5°, 180°, and 303.75°, respectively.

Noise is spread evenly across the switching cycle

resulting in more than 1.5 times reduction. To

achieve similar noise reduction without the interleave

will require the addition of an external LC filter.

Figure 50. Input Voltage Noise with Interleave

Similar noise reduction can be achieved on the

output of POLs connected in parallel. Figure 51 and

Figure 52 show the output noise of two ZY7120s

connected in parallel without and with 180°

interleave, respectively. Resulting noise reduction is

more than 2 times and is equivalent to doubling

switching frequency or adding extra capacitance on

the output of the POLs.

Figure 51. Output Voltage Noise, Full Load, No Interleave

Figure 52. Output Voltage Noise, Full Load, 180 Interleave

The ZY7120 interleave feature is similar to that of

multiphase converters, however, unlike in the case of

multiphase converters, interleave does not have to

be equal to 360/N, where N is the number of POLs in

a system. ZY7120 interleave is independent of the

number of POLs in a system and is fully

programmable in 11.25 steps. It allows maximum

output noise reduction by intelligently spreading

switching energy.

Note: Due to noise sensitivity issues that may occur in limited

cases, it is recommended to avoid phase lag settings of

112.5 and 123.75 degrees, otherwise false PG and/or OV

indications may occur.

8.4.3 Duty Cycle Limit

The ZY7120 is a step-down converter therefore VOUT

is always less than VIN. The relationship between

the two parameters is characterized by the duty

cycle and can be estimated from the following

equation:

MININ

OUT

,

Where, DC is the duty cycle, VOUT is the required

maximum output voltage (including margining),

VIN.MIN is the minimum input voltage.

It is good practice to limit the maximum duty cycle of

the PWM controller to a somewhat higher value

compared to the steady-state duty cycle as

expressed by the above equation. This will further

protect the output from excessive voltages. The duty

cycle limit can be programmed in the GUI PWM

Controller window or directly via the I2C bus by

writing into the DCL register shown in Figure 53.

ZY7120 20A DC-DC Intelligent POL Data Sheet

3V to 13.2V Input  0.5V to 5.5V Output

ZD-00194 Rev. 2.5, 01-Jul-10 www.power-one.com Page 28 of 34

DCL5 DCL4 DCL3 DCL2 DCL0 HI LO

Bit 7 Bit 0

R = Readable bit

W = Writable bit

U = Unimplemented bit,

read as ‘0’

- n = Value at POR reset

R/W-1 R/W-1 R/W-1 R/W-0 R/W-0 R/W-0 R/W-0

R/W-1

Bit 7:2 DCL[5:0], Duty Cycle Limitation

00h: 0

01h: 1/64

…

3Fh: 63/64

Bit 1: HI, ADC high saturation feed-forward

0: disabled

1: enabled

Bit 0: LO, ADC low saturation feed-forward

0: disabled

1: enabled

DCL1

Figure 53. Duty Cycle Li mit Register

8.4.4 ADC Saturation Feedforward

To speed up the PWM response in case of heavy

dynamic loads, the duty cycle can be forced either to

0 or the duty cycle limit depending on the polarity of

the transient. This function is equivalent to having

two comparators defining a window around the

output voltage setpoint. When an error signal is

inside the window, it will produce gradual duty cycle

change proportional to the error signal. If the error

signal goes outside the window (usually due to large

output current steps), the duty cycle will change to its

limit in one switching cycle. In most cases this will

significantly improve transient response of the

controller, reducing amount of required external

capacitance.

Under certain circumstances, usually when the

maximum duty cycle limit significantly exceeds its

nominal value, the ADC saturation can lead to the

overcompensation of the output error. The

phenomenon manifests itself as low frequency

oscillations on the output of the POL. It can usually

be reduced or eliminated by disabling the ADC

saturation or limiting the maximum duty cycle to 120-

140% of the calculated value. It is not recommended

to use ADC saturation for output voltages higher

than 2.0V.

The ADC saturation feedforward can be

programmed in the GUI PWM Controller window or

directly via the I2C bus by writing into the DCL

8.4.5 Feedback Loop Compensation

Feedback loop compensation can be programmed in

the GUI PWM Controller window by setting

frequency of poles and zeros of the transfer function.

The transfer function of the POL converter is shown

in Figure 54. It is a third order function with two

zeros and three poles. Pole 1 is the integrator pole,

Pole 2 is used in conjunction with Zero 1 and Zero 2

to adjust the phase lead and limit the gain increase

in mid band. Pole 3 is used as a high frequency low-

pass filter to limit PWM noise.

Z1 P1 Z2 P2 P3

0.1 1 10 100 1000

Freq

[kHz]

Magnitude[dB]

0.1 1 10 100 1000

Freq

[kHz]

-90

-45

-135

-180

+45

Phase

[°]

P1: Pole 1

P2: Pole 3

P3: Pole 3

Z1: Zero 1

Z2: Zero 2

Figure 54. Transfer Function of PWM

Positions of poles and zeroes are determined by

coefficients of the digital filter. The filter is

characterized by four numerator coefficients (C0, C1,

C2, C3) and three denominator coefficients (B1, B2,

B3). The coefficients are automatically calculated

when desired frequency of poles and zeros is

entered in the GUI PWM Controller window. The

coefficients are stored in the C0H, C0L, C1H, C1L,

C2H, C2L, C3H, C3L, B1, B2, and B3 registers.

Note: The GUI automatically transforms zero and pole

frequencies into the digital filter coefficients. It is strongly

recommended to use the GUI to determine the filter

coefficients.

Programming feedback loop compensation allows

optimizing POL performance for various application

conditions. For example, increase in bandwidth can

significantly improve dynamic response.

8.5 Current Share

The POL converters are equipped with the digital

current share function. To activate the current share,

interconnect the CS pins of the POLs connected in

ZY7120 20A DC-DC Intelligent POL Data Sheet

3V to 13.2V Input  0.5V to 5.5V Output

ZD-00194 Rev. 2.5, 01-Jul-10 www.power-one.com Page 29 of 34

parallel. The digital signal transmitted over the CS

line sets output currents of all POLs to the same

level.

When POLs are connected in parallel, they must be

included in the same parallel bus in the GUI System

Configuration window shown in Figure 55. In this

case, the GUI automatically copies parameters of

one POL onto all POLs connected to the parallel

bus. It makes it impossible to configure different

performance parameters for POLs connected in

parallel except for interleave and load regulation

settings that are independent. The interleave allows

to reduce and move the output noise of the

converters connected in parallel to higher

frequencies as shown in Figure 51 and Figure 52.

The load regulation allows controlling the current

share loop gain in case of small signal oscillations. It

is recommended to always add a small amount of

load regulation to one of the converters connected in

parallel to reduce loop gain and therefore improve

stability.

8.6 Performance Parameters Monitoring

The POL converters can monitor their own

performance parameters such as output voltage,

output current, and temperature.

The output voltage is measured at the output sense

pins, output current is measured using the ESR of

the output inductor and temperature is measured by

the thermal sensor built into the controller IC. Output

current readings are adjusted based on temperature

readings to compensate for the change of ESR of

the inductor with temperature.

An 8-Bit Analog to Digital Converter (ADC) converts

the output voltage, output current, and temperature

into a digital signal to be transmitted via the serial

interface. The ADC allows a minimum sampling

frequency of 1 kHz for all three values.

Monitored parameters are stored in registers (VOM,

IOM, and TMON) that are continuously updated. If

the Retrieve Monitoring bits in the GUI Group

Configuration window shown in Figure 56 are

checked, those registers are being copied into the

ring buffer located in the DPM. Contents of the ring

buffer can be displayed in the GUI IBS Monitoring

Window shown in Figure 57 or it can be read directly

via the I2C bus using high and low level commands

as described in the ‘”DPM Programming Manual”.

ZY7120 20A DC-DC Intelligent POL Data Sheet

3V to 13.2V Input  0.5V to 5.5V Output

ZD-00194 Rev. 2.5, 01-Jul-10 www.power-one.com Page 30 of 34

Figure 55. GUI System Configuration Window

ZY7120 20A DC-DC Intelligent POL Data Sheet

3V to 13.2V Input  0.5V to 5.5V Output

ZD-00194 Rev. 2.5, 01-Jul-10 www.power-one.com Page 31 of 34

Figure 56. POL Group Configuration Window

9. Safety

The ZY7120 POL converters do not provide

isolation from input to output. The input devices

powering ZY7120 must provide relevant isolation

requirements according to all IEC60950 based

standards. Nevertheless, if the system using the

converter needs to receive safety agency approval,

certain rules must be followed in the design of the

system. In particular, all of the creepage and

clearance requirements of the end-use safety

requirements must be observed. These

requirements are included in UL60950 - CSA60950-

00 and EN60950, although specific applications may

have other or additional requirements.

The ZY7120 POL converters have no internal fuse.

If required, the external fuse needs to be provided to

protect the converter from catastrophic failure. Refer

to the “Input Fuse Selection for DC/DC converters”

application note on www.power-one.com for proper

selection of the input fuse. Both input traces and the

ZY7120 20A DC-DC Intelligent POL Data Sheet

3V to 13.2V Input  0.5V to 5.5V Output

ZD-00194 Rev. 2.5, 01-Jul-10 www.power-one.com Page 32 of 34

chassis ground trace (if applicable) must be capable

of conducting a current of 1.5 times the value of the

fuse without opening. The fuse must not be placed

in the grounded input line.

Abnormal and component failure tests were

conducted with the POL input protected by a fast-

acting 65 V, 15 A, fuse. If a fuse rated greater than

15 A is used, additional testing may be required.

In order for the output of the ZY7120 POL converter

to be considered as SELV (Safety Extra Low

Voltage), according to all IEC60950 based

standards, the input to the POL needs to be supplied

by an isolated secondary source providing a SELV

also.

Figure 57. IBS Monitoring Window

ZY7120 20A DC-DC Intelligent POL Data Sheet

3V to 13.2V Input  0.5V to 5.5V Output

ZD-00194 Rev. 2.5, 01-Jul-10 www.power-one.com Page 33 of 34

10. Mechanical Drawings

All Dimensions are in mm

Tolerances:

0.5-10 0.1

10-100 0.2

Pin Coplanarity: 0.1 max

1.5

3.4

0.25

10.25129.75

9.112

15.75

8.25±0.3

3.25

Pin 1

3.5

SMT Pickup

Center Point

1.5±0.1

0.4

(x20)

27.94

32±0.3

13.4

14±0.3

2.03

1.27

(x10)

0.6 2.54 1.27

(x10) 4.3

2.5

0.6

SMT Pickup Tab

Tilt Specification:

<5° from vertical,

after assembly

Figure 58. Mechanical Drawing

Figure 59. Pinout Diagram (Bottom View)

ZY7120 20A DC-DC Intelligent POL Data Sheet

3V to 13.2V Input  0.5V to 5.5V Output

ZD-00194 Rev. 2.5, 01-Jul-10 www.power-one.com Page 34 of 34

6 9

8.6

10 10 6

0.8

(x 22)

Pin 1

1.27

(x 10)

1.27

(x 10)

2.54 2.03

1.8

1.2

(x 3)

Unexposed thermal copper

area associated with each pad

must be free from other traces

Figure 60. Recommended Pad Sizes

Figure 61. Recommended PCB Layout for Multilayer PCBs

Notes:

1. NUCLEAR AND MEDICAL APPLICATIONS - Power-One products are not designed, intended for use in, or authorized for use as critical

components in life support systems, equipment used in hazardous environments, or nuclear control systems without the express written

consent of the respective divisional president of Power-One, Inc.

2. TECHNICAL REVISIONS - The appearance of products, including safety agency certifications pictured on labels, may change depending on

the date manufactured. Specifications are subject to change without notice.

I2C is a trademark of Philips Corporation.