TPS40400 Step-Down Regulator with PMBus Delivering 1.8V at 4A Reference Design


Design files


PMP11140 is a single-phase switching regulator accepting an input range of 4.5V to 13.2V and providing an output voltage of 1.8V capable of supplying 4A of current. This reference design shows 1.8Vout, 4A (3A without a fan) for CPU I/O and other applications in a 22cm by 12.6cm single sided footprint. A rich test interface including an on board dynamic load is provided.

  • PMBus programming, configuration, control, and telemetry
  • 85% peak efficiency
  • Well documented thermal performance both with and without fan.
  • On board high speed dynamic test load to verify dynamic performance
  • 0.9” x 0.5” total power supply area with all parts on same side
  • Supported by TI’s Fusion GUI PMBus designer FUSION_DIGITAL_POWER_DESIGNER
Output voltage options PMP11140.1
Vin (Min) (V) 4.5
Vin (Max) (V) 13.2
Vout (Nom) (V) 1.8
Iout (Max) (A) 4
Output Power (W) 7.2
Isolated/Non-Isolated Non-Isolated
Input Type DC
Topology Buck- Synchronous
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A fully assembled board has been developed for testing and performance validation only, and is not available for sale.

Design files & products

Design files

Download ready-to-use system files to speed your design process.

TIDUAA9.PDF (2258 K)

Test results for the reference design, including efficiency graphs, test prerequisites and more

TIDRG01.PDF (196 K)

Detailed schematic diagram for design layout and components

TIDRG02.PDF (116 K)

Complete listing of design components, reference designators, and manufacturers/part numbers

TIDRG03.PDF (173 K)

Detailed overview of design layout for component placement


Design file that contains information on physical board layer of design PCB

TIDRG04.PDF (1381 K)

PCB layer plot file used for generating PCB design layout


Includes TI products in the design and potential alternatives.

Buck controllers (external switch)

TPS404003-V to 20-V, 30-A, synchronous buck controller with PMBus™, including Telemetry

Data sheet: PDF | HTML
N-channel MOSFETs

CSD17313Q230-V, N channel NexFET™ power MOSFET, single SON 2 mm x 2 mm, 32 mOhm

Data sheet: PDF | HTML
N-channel MOSFETs

CSD85301Q220-V, N channel NexFET™ power MOSFET, dual SON 2 mm x 2 mm, 27 mOhm, gate ESD protection

Data sheet: PDF | HTML

Technical documentation

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Type Title Date
* Test report PMP11140 Test Results Jul. 15, 2015
Technical article Power Tips: Voltage mode or current mode? Oct. 02, 2015
Technical article Power Tips: Voltage mode or current mode? PDF | HTML Oct. 02, 2015

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