Download TI First

TPS544B25/C25
PMBus™ Voltage Mode
20A/30A SWIFT™ Buck Converter
with Frequency Synchronization
in PowerStack™ QFN package
1
TPS544B25/C25
4.5-18V, 20A/30A Voltage Mode SWIFT™ Buck Converter with PMBus
Programming and Telemetry, and Frequency Synchronization
Features
Benefits
•4.5V to 18V Input Voltage, 0.5V to 5.5V Output Voltage
• Works with 5V and 12V bus, Wide Output Voltage Range
•Programmable Output Voltage and Margining
• Easy programming of output voltage eliminating external circuits
•PMBus 1.2 telemetry on voltage, current and temperature
• Easy characterization of boards, real-time monitoring of systems
for increased reliability and diagnostics
•Differential mode Vsense; ±0.5% Accurate Vref from -40C to 85C,
±1% to 125C junction temperature range
•Frequency Synchronization
•5.5/2.0mohm High Side/Low Side MOSFET Rds(on)
•Nonvolatile memory for storing power supply values
• Tight voltage regulation; spec includes error amp offset; more
headroom to meet tight overall tolerance specs
• Can be synchronized to external clock for lower EMI
• 88% efficiency at 12VIN, 1.5Vout/30A, 460KHz Fsw, no airflow
•Easy-to-use Fusion Digital Power Designer GUI
• Ease of design, can store new values, and create a new design in
<1 minute
•40-pin, 5x7mm PowerStack™ package with large, single GND pad;
• Ease of validation, export PMBus script for manufacturing
•Choice of hiccup or latchoff OCP
• Easy top layer PCB layout, easy heatsinking into PCB GND
layers, excellent thermal performance (30A SOA)
Vin
Applications
CVIN
VIN
VDD
VSET
DIFFO
FB
VOUTS+
VOUTSBOOT
COMP
Pin Compatible
BP3
TPS544C25
30-A
TSNS/SS
20-A
SMBALRT#
TPS544B25
CNTL
AGND
SW
GND
DATA
Iout
TPS544B25/C25
CLK
Device
Vout
PGOOD
SYNC/
RESET_B
RT
ADDR1
Enterprise Server/Storage Systems
Ethernet Switches, Base Stations, and Routers
Video Surveillance
Industrial and Embedded computers
Software Defined Radios
Factory Automation
High-End Programmable Logic Controllers
ADDR0
•
•
•
•
•
•
•
CVDD
BP6
2
TPS544B25/C25
TI First
4.5-18V, 20A/30A Voltage Mode SWIFT™ Buck Converter with
PMBus programmability and Voltage, Current and Temperature
Telemetry
Features
Discovery
Questions
Pricing &
Availability
• Control Mode: Voltage Mode with Input Feedforward
• Interface: PMBus 1.2
• Feedback Voltage Accuracy: ±1% from -40ºC to
+º125C Junction Temperature
• MOSFET Rds(on), High Side/Low Side: 5.5/2mohm
• Voltage Sensing: Differential Remote
• PMBus programming: Soft Start, Soft Stop, Delays,
PGOOD, OVP, UVP, OTP, UVLO, ILIM, Vout, Voltage
Margin, OverCurrent Protection Mode (Latch Off or
Hiccup)
• EMI control: Frequency Synchronization
• Monitoring Accuracy: ±15% (IOUT), ±2% (VOUT),
±5ºC (External Temperature)
• Reset: Reset Vout Function (without power cycling)
• Package: 5x7mm 40 pin PowerStack™ QFN
3
TPS544B25/C25
TI First
4.5-18V, 20A/30A Voltage Mode SWIFT™ Buck Converter with
PMBus programmability and Voltage, Current and Temperature
Telemetry
•
Do you have high-current ASICs or DSPs in your system?
• TPS544B25/C25 can power up to 30A ASICs with high
efficiency, and power density, while adding PMBus
programming and monitoring for ease of use and system
diagnostics.
•
Is thermal performance and power density critical to your ASIC
power design?
• TPS544B25/C25 enables easy heatsinking into the internal
PCB GND layers with GND vias connected to the large, single
GND pad on the bottom of the IC; PMBus, up to 1MHz Fsw,
and low FET Rds(on) enable a single sided 32x36mm 30A
solution with 112ºC IC case temp at 30A with no airflow (max
Tjunction is 150ºC)
Features
Discovery
Questions
Pricing &
Availability
•
Do you want to control EMI?
• TPS544B25/C25 has Frequency Synchronization via
connection to an external clock
4
TPS544B25/C25
TI First
4.5-18V, 20A/30A Voltage Mode SWIFT™ Buck Converter with
PMBus programmability and Voltage, Current and Temperature
Telemetry
Features
Discovery
Questions
Pricing
Availability
Resources
Product Info: TPS544B25/C25
Pricing 1Ku: TPS544C25 $4.49, TPS544B25 $4.08
Availability:
– Silicon:
– Samples Now
– Full production Now
– Evaluation Boards: TPS544B25/C25EVM, Now
– Software: Fusion Digital Power Designer, Now
– Datasheet: See TI.com, Now
Additional resources:
Support: Digital Power Landing Page
TI Designs: Etherner Switch PMBus POL TI Design using the
TPS544B25/C25
USB-to-GPIO Adapter: HPA174 USB Interface Adapter EVM
SWIFT POL: www.ti.com/swift
TPS544B25/C25
4.5-18V, 20A/30A Voltage Mode SWIFT™ Buck Conveter with PMBus
programmability and Voltage, Current and Temperature Telemetry
• Why were these parts developed?
– High-current ASIC core and I/O power rails are increasing in server and
communication systems. Customers require highly efficient, power dense
step down dc/dc converters with higher level of integration to achieve low
system cost, ease of use, complete protection, and better reliability.
– Customers need PMBus to monitor ASIC rails for characterization,
debugging, as well as remote diagnostics through IOUT, VOUT, TEMP and
FAULT telemetry .
– Customers want to be able to create new designs fast, and ensure low EMI
risk.
• What differentiates this part?
– TI’s first Voltage Mode PMBus High-Current Buck Converter
– Frequency Synchronization for low EMI risk
– Standard PMBus rev1.2 VOUT_COMMAND requires no firmware change to
adjust Output Voltage
6
TPS5423x/5433x/5453x
TPS62175
28V, 2-5A, Synchronous/non-synchronous
28V, 500mA
LM34922
20V, 1A
LMR12010
20V, 5A, Synchronous,
CM, Flexible, Eco-Mode
LMR12015/20
20V, 2A, nonsynchronous
Need more? See
Parametric
Search:
Buck
Converter 730Vin
TPS51362
22V, 10A, Low Iq
TPS65286
TPS51363
TPS51367
6A buck+ dual USB switch
22V, 8A
22V, 12A, Low Iq
TPS65261/2/3, TPS65251
TPS62110
17V, 1.5A
LM21305
28V, 2A, Nonsynchronous,
COT, 1MHz
LM2734
20V, 1A, non-sync
TPS544C25
TPS65400
18V, 30A, VM
4.5V-18V input, 3A/2A/2A triple buck, (+LDO), (+I2C) 4A/4A/2A/2A, +PMBus/I2C
TPS544C20
< 20V Input Max
Maximum Input Voltage (V)
≥ 20V Input Max
Step-Down Converter: 7V – 30V Vin
TPS65266
TPS65273V/6V/9V
2.7V -6.5V, 3A/2A/2A, triple buck +600mA LDO
dual buck+ I2C interface,
18V, 30A,
PMBus Config +
Telemetry
TPS54x94/54x95 /542941/542951
TPS62184
TPS56221
18V; 2A~4A, Dual buck
17V, 5A
14V, 25A
LM2736
TPS65580/1
TPS54x25/54x26, TPS54x27/54x28
TPS544B25
18V, 750mA
18V, 2.5A/1.5A/1.5A Triple buck
18V, 2-6.5A
18V, 20A, VM
TPS560200
TPS53511
17V, 500mA, SOT-23
18V, 1.5A
TPS62170/72/Q1
TPS62160/-Q1
TPS65257/8
17V, 1A
3A buck + USB switches
17V, 500mA
TPS62125
17V, 300mA
TPS65283/-1
3.5A/2.5A dual buck, integrated USB switch18V, Dual 3.5A+3.5A
TPS/TLV6215x TPS5622xx/5632
/A
xx
17V, 1A
17V, 2-3A, SOT-23
TPS544B20
TPS65279
TPS563900
18V, 5A/5A Dual buck
TPS566250
TPS56X20
17V, 6, high res VID
control
17V, 5A~12A, VID
control
TPS54320
TPS54620/2
TPS54020
17V, 3A
17V, 6A
17V, 10A
18V, 20A
PMBus Config +
Telemetry
TPS53353/5
15V, 20/30A
TPS56121
14V, 15A
TPS62120
TPS62160
TPS62134
TPS56628
TPS56921
17V, 1A
17V, 3.2A
18V, 6A
TPS53515
15V, 75mA
17V, 9A, I2C
18V, 12A
TPS62122
LM2651
TPS6214x/xA
TPS62180
TPS53513
14V, 1.5A
17V, 2A
TPS53915
15V, 75mA
TLV/TPS62130
/A
15V, 6A
18V, 8A
18V, 12A, PMBus™
<1
A
1A
2A
17V, 3A
3A
Output Current (A)
4-6A
8-10A
>10
A
NEW
EXISTING
Success Stories: TPS544B25/C25
in Base Stations
Device Overview
TI First
RTM Call
Where We Won
Why We Won
Who: Tier 2 Base Station manufacturer
•
On TI TIC6630 Reference Design
Enabled customer to cut-and-paste TI
Design for quick Time To Market (TTM)
•
AVS Capability PMBus
VOUT_COMMAND enabled Vout
Adjustment On The Fly (AVS)
•
Tight Voltage Regulation ±1% over
temperature enabled customer more
headroom and output capacitor savings for
±5% total regulation spec (FB accuracy,
ripple, DC regulation, load transients)
•
Highest density solution on the market,
reduced total cost, board space and
component count
•
Shortened development cycle Software
GUI enabled hardware engineers to
modify, and configure on the fly (NVM onboard) through PMBus, no coding or
software engineer support needed
8
What: TPS544B25/C25
Where: TI TCI6630 (Lamar) DSP core rail in
LTE Base Station board
Volume: 50ku / year
Customer Need: High-Efficiency, Power
Dense 30A buck converter with Adaptive
Voltage Scaling (AVS) capabilities and tight
voltage regulation due to total +/-5%
regulation spec
TPS544C25
Success Stories: TPS544C25
powering TI’s AM5K2E02/04 DSP on Gateway
Device Overview
TI First
RTM Call
Where We Won
Why We Won
Who: Tier 2 Comm Gateway OEM in Europe
•
On TI AM5K2E02/04 Reference Design
Enabled customer to cut-and-paste TI
Design for quick Time To Market (TTM)
•
AVS Capability PMBus VOUT_COMMAND
enabled option for Vout Adjustment On The
Fly (AVS) to optimize performance
•
Output Voltage/Current/Temperature
Monitoring enabled monitoring of highcurrent DSP core rail for observing system
performance and increasing reliability
•
Highest density solution on the market,
reduced board space and component count
•
Shortened development cycle PMBus
GUI enabled engineers to modify, and
configure on the fly (NVM on-board)
through PMBus, no coding or software
engineer support needed; programming
script generated by putting PMBus
commands together
9
What: TPS544C25
Where: Smart Gateway - AM5K2E02/04 DSP
core power rail
Volume: 100KU/year
Customer Need: High-Efficiency, Power
Dense 30A buck converter with Adaptive
Voltage Scaling (AVS) capabilities and
Output Voltage/Current and Temperature
Monitoring
Competitive Landscape (1/2)
TPS544C25
IR3846M
ISL8271M
LTC3880
Device Type
Single Phase iFET
Single Phase iFET
Single Phase Module
Multi-Phase Controller
Input Voltage
4.5 - 18V
1.5 – 21V
4.5 – 14V
4.5 – 24 V
Programmable VIN UVLO
Through PMBus
Through External Pin
Through PMBus
Through PMBus
Reference and Accuracy
Tj = -40oC to 125oC
0.5V – 0.6V, ±1.5%
0.6V – 1.5V, ±1%
0.6V, ±1%
±1% Vout accuracy over line, load and
temp, TA = -20oC to 85oC
0.5% at TA=25C
0.5 - 5.5V
0.6V – 0.86*Pvin (4.5-7.5V bias)
0.54 - 5.5V
0.5 to 5.4 V
True Differential Sense
Yes
Yes
Yes
Yes
Output Voltage Margin
Yes (VOUT_COMMAND)
Yes
Yes
Yes
Yes (through VOUT_COMMAND)
No
Yes (through VOUT_COMMAND)
Yes (VOUT_COMMAND)
No
Yes
No
No
Sequential (programmable
TON_RISE TON_DELAY
TOFF_FALL and TOFF_DELAY)
Sequential
Ratiometric
Simultaneous
Sequential (PMBus MFR command )
Sequential
TON_DELAY, TOFF_DELAY, TON_RISE,
TOFF_FALL
Low-side OC Limit
Programmable
3 Selectable
Programmable
Programmable (Avg. DCR)
High-side OC Limit
Fixed
No
Unknown (DCR sensing)
Programmable Fixed Options
Restart, Shutdown, Ignore
OV Latch-off, OC Hiccup
restart or latch off; plus VIN OV/UV, DRV
OV/UV, UC
Pull-Down, Hiccup, Latch-Off, Ignore
Yes
Yes
Unknown
Unknown
Features
Output Voltage
Digital AVS Support
External tracking
Sequencing
Output UVP/OVP/OCP Response
OV Enabled During Soft-Start
Programmable 200kHz-1000kHz
through ext. pin
Selectable 300kHz-1500kHz
Programmable 300kHz-1066kHz through
PMBus
Programmable through PMBus AND
Resistor
(250kHz-1000kHz), Phase shift MP
Synchronization
Yes
Yes (PLL based)
Yes, (PLL based), phase spreading for upto
16 devices
Yes
PMBus Support
PMBus 1.2 (52 commands to
customer)
No
PMBus 1.2 (84 commands to customer)
PMBus 1.1
Yes, V/I/T
±2%/±15%/±5C
No
Yes, output V (±2% -40C to 85C)/I (±2A at
room), input V, internal T(±5C), ext. T, Duty,
Fsw, VDRV
Yes – VIN, IIN, VOUT, IOUT, TEMP, Duty,
Pout
VM with FeedForward
VM with FeedForward, Body
Braking for Load Dump Trans.
Digital Control
Current Mode Control
Control
Switching Frequency
Telemetry Through PMBus
FET, Package
Control Topology
Eco-Mode
No
No
No
Yes
External Compensation
Yes
Yes
No
Yes
D-CAP2/3 with Offset Reduction
N/A
N/A
N/A
No
D-CAP2/3 with RC Optimization
N/A
N/A
N/A
No
Gen 2.1, 25V/10V
30A: HS/LS=5.5/2.0mW
MCM, 25V/10V
35A: HS/LS=3.1/1.27mW
33A
Controller
20/15ns
Unknown, post package trim
Unknown
Unknown
26pin LQFN 5x7x1mm
40pin HDA 17x19x3.55mm
40pin LQFN 6x6mm
Rds_on and TDC current
Dead-Time
Package
40pin LQFN 5x7x1.5mm
TI Confidential – NDA Restrictions
10
Competitive Landscape (2/2)
TPS544C25
Device Type
Input Voltage
Programmable VIN UVLO
Reference and Accuracy
Tj = -40oC to 125oC
Output Voltage
Features
True Differential Sense
Output Voltage Margin
Digital AVS Support
External tracking
Single Phase iFET
2+1 Digital Controller
Single Controller
4.5 - 18V
2.9 – 3.6 V (controller)
4.5V – 16V UVLO Power Stage
4.5V to 14V
Through PMBus
R-Divider + i2C
Through PMBus 4V - 12V
0.5V – 0.6V, ±1.5%
0.6V – 1.5V, ±1%
0.5% (1-1.5V), 1.1% (1.55-2.3V)
5 mV (0.8-0.995V), 8mV (0.25-0.8V)
0 to 85 C
0.5% (25C), 1% (-40 to 85C)
0.5 - 5.5V
0.25 – 2.3 V
0.5 to 5.25V
Yes
Yes
Yes
Yes (VOUT_COMMAND)
Yes
Yes
Yes (through VOUT_COMMAND)
Yes (PMBus Margin + i2c VID)
Yes (VOUT_COMMAND)
No
No
Yes
Sequentiel/Simultaneous
(2+1 can start at the same time)
MFR Ton_rise, delays
Sequential + Ratiometric (tracking)
TON_RISE, TOFF_FALL, TON/OFF_DELAY
Low-side OC Limit
Programmable
Programmable (DCR) “slow ocp”
DCR (Programmable)
High-side OC Limit
Fixed
Programmable “Fast OCP”
DCR (Programmable)
Restart, Shutdown, Ignore
Shutdown, ON until Vout < UV
Restart, Shutdown, ignore
Yes
Yes (Programmable)
Unknown
Programmable 200kHz-1000kHz through
ext. pin
200 kHz to 2 MHz
300 kHz – 1 Mhz
Synchronization
Yes
No
Yes
PMBus Support
PMBus 1.2 (52 commands to customer)
Yes (i2C + PMBus)
Information not in DS
Yes
Yes, V/I/T
±2%/±15%/±5C
Yes, VIN, IIN, VOUT, IOUT, POUT, PIN,
EFFICIENCY
VIN, VOUT, IOUT, VOUT, DUTY, FREQUENCY, TEMP (ext)
VM with FeedForward
Digital
Digital
Eco-Mode
No
Yes
No
External Compensation
Yes
No
No
D-CAP2/3 with Offset Reduction
N/A
n/a
n/a
N/A
n/a
n/a
Gen 2.1, 25V/10V
30A: HS/LS=5.5/2.0mW
External Power Stage
External Power Stage
Output UVP/OVP/OCP Response
OV Enabled During Soft-Start
Switching Frequency
Control
MAX15301
Sequential (programmable TON_RISE
TON_DELAY TOFF_FALL and
TOFF_DELAY)
Sequencing
Telemetry Through PMBus
Control Topology
FET, Package
IR36021
D-CAP2/3 with RC Optimization
Rds_on and TDC current
Dead-Time
Package
20/15ns
Power stage
Power stage
40pin LQFN 5x7x1.5mm
32 pin 5x5 QFN
32 pin 5 x 5 QFN
TI Confidential – NDA Restrictions
11
2 Parts/families that work well together
TPS544B25/C25 and UCD90240
TI First
RTM Call
20A/30A PMBus SWIFT™ step-down dc/dc converters + 24-rail PMBus Sequencer/Manager
Performance
Capabilities
• TPS544B25/C25
• 4.5V to 18V Input, 0.6V to 5.5Voutput
• 20A and 30A pin-to-pin devices
• 5.5/2mOhm High/Low-Side FET Rds(on)
• Adaptive Voltage Scaling through PMBus
• Output Voltage ,and Current Telemetry
• UCD90240
• Monitor, Enable, Margin 24 voltage rails
• 100 Fault Logs
• Black Box Fault Log with fine time stamp
• 256k Flash Memory
Cascadable by 4 for 96 rail management
PMBus
3.3VIN
• Ability to regulate voltage rails up to 30A with 1%
Vref accuracy up to 125ºC
• High power density and complete rail management
and reporting through PMBus
• Closed loop Adaptive Voltage Scaling and
Margining with Frequency Synchronization
Applications
• Communications
• Ethernet Switches, Base Stations
• Enterprise Servers and Storage
• Performance Servers, Storage Attach Boxes
• Test & Measurement
• FPGA Testers, Network/Spectrum Analyzer
4.5V to 18V VIN
UCD90240
TPS544B25/C25
24-Rail
PMBus
Sequencer/Manager
.
.
.
24
analog
POL
voltage
rails
20A/30A
SWIFT™
5 x 7mm
PowerStack ™QFN
12
TI Designs/Application: PMP10896
Getting Your Customer Started
Device Overview
TI First
RTM
Complete PMBus Ethernet Switch POL Rail Power Supply Reference Design PMP10896
Solution Features
Solution Benefits
•
•
•
•
•
•
Hot Swap, DC/DC Regulators and
Sequencers/Monitors with PMBus
UCD90240 PMBus Manager
• 24 rails, cascadable to 96
Eight (8) Voltage Regulators
Single and Multiphase Buck Converters
Fusion GUI with Closed-Loop Adaptive Voltage
Scaling (AVS)
•
•
Complete PMBus power system for 3
ASIC/FPGA cores, DDR3 core memory, and
auxiliary voltages found on high-performance
Ethernet Switches
12V / 300W system power solution with eight
(8) point-of-load buck converters, including
single and multiphase buck power supplies
High power density power conversion with
Inductor-On-Top -IC designs
Tools & Resources
PMP10896 pictured
PMP10896 TI Fusion GUI
•PMP10896
•Power ICs:TPS544B25/C25,
TPS53355, TPS53319,
TPS53513, TPS53515,
TPS544C25x2, TPS40428,
LM25066A, TPS62153,
TPS715A33
•Includes: Test Data, BOM,
Schematic, Design Files
13
TI Design Tools: Web-Orderable EVM
Device Overview
TI First
RTM
TPS544C25EVM-681 Evaluation Module
EVM Features
EVM Benefits
•
•
•
•
•
Regulated 0.95-V output up to 30-A DC, steadystate output current
Configurable features via the PMBus interface
include Output Voltage, UVLO, Soft Start,
Enable, Fault Limits and Programmable
Response
Convenient Test Points for Probing Critical
Waveforms
Optional External Temperature Sensor
•
•
•
Up to 30A Buck Converter with PMBus
Configurability and Monitoring
Ease to use Fusion GUI Software for PMBus
Enables measuring key power supply
parameters including line/load regulation,
efficiency, Bode Plot, Load Transient Response,
Output Voltage Ripple, Pre-Biased Start-Up,
Sequencing/Control and System Protection and
Monitoring features
Thermal Image available on User Guide
Tools & Resources
•TPS544C25EVM-681
14
Device Overview
TI First
Who to Sell To…
Application Area #1
(Communications)
Application Area #2
(Servers/Storage)
Application Area #3
(Test & Measure)
Example End
Equipments
• Cellular Basestations
• RRH (remote radio heads)
• DAS/Cellular Repeaters
• Intel VR12.5/VR13 Servers
• Storage Attach Boxes
• High-Current Storage Controller
ASICs on Enterprise SSD
Cards/HBAs/HICs
•
•
•
•
Key Market
Differentiators
• Full PMBus telemetry from
Industry’s first 30A PMBus
Voltage Mode Converter
• High Switching Frequency with
Low Rds(on) FETs in
PowerStack QFN enables
Single-Sided 30A solution in
32mm x 36mm PCB area
• 1% Vref accuracy over
temperature for tight load
regulation
• Frequency Synchronization up
to 1.2MHz for low EMI
• Pinstraping for default output
voltages with AVS through
PMBus
• Full Differential Remote Voltage
Sensing for tight load regulation
• Full PMBus telemetry from
Industry’s first 30A PMBus
Voltage Mode Converter
• High Switching Frequency with
Low Rds(on) FETs in
PowerStack QFN enables
Single-Sided 30A solution in
32mm x 36mm PCB area
• 1% Vref accuracy over
temperature for tight load
regulation
• Frequency Synchronization up to
1.2MHz for low EMI
• Pinstraping for default output
voltages with AVS through
PMBus
• Full Differential Remote Voltage
Sensing for tight load regulation
• Full PMBus telemetry from
Industry’s first 30A PMBus
Voltage Mode Converter
• High Switching Frequency with
Low Rds(on) FETs in
PowerStack QFN enables
Single-Sided 30A solution in
32mm x 36mm PCB area
• 1% Vref accuracy over
temperature for tight load
regulation
• Frequency Synchronization up
to 1.2MHz for low EMI
• Pinstraping for default output
voltages with AVS through
PMBus
• Full Differential Remote
Voltage Sensing for tight load
regulation
FPGA Testers
Spectrum Analyzer
Vector Analyzer
Communications/Network
Testers
15
FAQs
• What are the key upgrades in TPS544C25/B25 vs. TPS544C20/B20?
– Voltage–mode topology for frequency synchronization to eliminate beat noise
and reduce EMI/ EMC.
– PMBus 1.2 facilitates easy AVS and standard PMBus VOUT_COMMAND (no
firmware change)
• Is the TPS544C25/C25 considered a superior replacement for
TPS544C20/B20?
– TI offers a portfolio of products – with different advantages - to meet varying
customer applications needs; For example, TPS544C20/B20’s DCAP2 mode
has lower undershoot and faster response to load transients without the need
for external compensation; TPS544C25/B25’s voltage-mode offers fixed,
synchronizable frequency to eliminate beat noise and reduce EMI/ EMC.
• Can the TPS544C25/B25 be stacked for higher power requirements?
– No, these converters are designed for single-phase operation. Refer to TI’s
multi-phase controllers with PMBus for additional options.
16
FAQs
• Why is the output voltage limited to 5.5V? Why are higher duty cycles not
supported?
– . The device’s architecture has been optimized for target applications that
typically require very low core and I/O voltages. The Output Voltage is limited by
Max DIFFO Output Voltage – datasheet spec is VBP6-0.2
• Can the TPS544B25/C25 be used without PMBus?
– It can be powered up and start up with no PMBus commands to an output voltage
set by a resistor from the VSET pin to AGND. You can short VSET pin to AGND
(no resistor required) and this sets the default output voltage to 0.95V.
• What advantages does PMBus offer over a device with a simple I2C?
– No need to write a Software Program; you can put together a script by putting
PMBus Commands in a sequence and selecting the values in the registers
• Do I have to use the Fusion GUI from TI?
– Yes, for validation and prototyping; a PMBus command script can be generated
for high-volume programming
17
FAQs
• Are the efficiencies and thermal performance for the TPS544C25/B25 similar
to those for TPS544C20/B20?
– The TPS544B20/C20 has lower High-Side FET Rds(on) for slightly higher
efficiency in high duty applications (high Vout); the TPS544B25/C25 has lower
Low-Side FET Rds(on) for slightly higher efficiency in low duty applications (low
Vout)
• Despite the same Rdson spec, why does the TPS544C25 have a price
premium over the TPS544B25?
– The family is designed to support up to 30A load current. The TPS544B25 offers
a lower-priced p2p alternative with identical efficiencies as the TPS544C25 up to
20A load. Furthermore, the customer may qualify one member of the family in
their system and easily transition to the other without having to re-qualify due to
differences in silicon. The TPS544B25/C25 have different Current Limit,
OverCurrent FAULT and WARN thresholds.
18
FAQs
• Despite needing external compensation and having higher Hi-Side FET
Rdson (5.5mOhms vs. 4.5mOhms), why does the TPS544B25/C25 cost
more than the TPS544B20/C20?
Analyzing overall system performance (and corresponding value) is more
meaningful and encouraged rather than individual IC price comparisons.
– TPS544C25/B25 offer Frequency Synchronization for EMI/noise control without
the need for expensive external filters
– TPS544C25/B25 has standard rev 1.2 PMBus VOUT_COMMAND for AVS that
requires no MGFR_SPECIFIC Register programming and no firmware change
– TPS544C25/B25 has RESET Vout function (SYNC/RESET pin) that resets to the
default Output Voltage with no power cycling required
– TPS544C25/B25 has PMBus VOUT_TRANSITION_RATE command to control
the output voltage slew rate for flexible Margining and Adaptive Voltage Scaling
(AVS) – 8 settings
– TPS544C25/B25 has 0.5V to 1.5V reference, so there is no need for bottom
feedback resistor for ASIC and FPGA core and I/O rails, enabling tighter output
voltage accuracy than the TPS544B20/C20 because it eliminates the resistor
tolerance as one of the sources for error.
19