1 Features

• 4V to 18V input voltage without external bias

• 2.7V to 18V input voltage with external bias

• 0.4V to 5.5V output voltage

• Supports 35A single-phase or 2 ×, 3 ×, or 4 ×

stacked configurations

• Rdson_HS = 3.3mΩ, Rdson_LS = 1mΩ

• 400kHz to 2MHz operating frequency (four

discrete settings through pinstrap, additional

settings through PMBus)

• PMBus® programmability

– Revision 1.5 Compliant with PASSKEY security

feature

– Input voltage, output voltage, output current,

temperature telemetry

– Programmable overcurrent, overvoltage,

undervoltage, overtemperature protections

– Includes single command write function in

stacked configuration

– Extended write protection feature

– Non-volatile memory to store configuration

settings

• Two methods for programming the output voltage

– Internal resistor divider (discrete settings), with

boot-up voltage selected by pin strapping

– External resistor divider (continuous settings),

with boot-up voltage selected by VBOOT field

• Precision voltage reference and differential remote

sense for high output accuracy

– +/– 0.5 DAC accuracy from 0°C to 85°C

junction

– +/– 1 VOUT tolerance from –40°C to 125°C

junction

• Selectable FCCM/DCM in single phase only

• Start-up without PMBus communication through

pin strapping

• Safe start-up into prebiased output

• Programmable soft-start time from 0.5ms to 16ms

• Programmable soft-stop time from 0.5ms to 4ms

• D-CAP4 control topology with fast transient

response, supporting all ceramic output capacitors

• Programmable internal loop compensation

• Selectable cycle-by-cycle valley current limit

• Open-drain power-good output

2 Applications

• Server and cloud-computing POLs

• Hardware accelerator

• Network interface card

3 Description

The TPS546C25 device is a highly integrated, buck

converter with D-CAP4 control topology for fast

transient response. All programmable parameters can

be configured by the PMBus interface and stored

in NVM as the new default values to minimize the

external component count. Pinstrap options allow for

configuration as primary or secondary, stack position

and stack number, DCM (single phase only) or FCCM,

overcurrent limit, fault response, internal or external

feedback resistor, output voltage selection or range,

switching frequency, and compensation.

The PMBus interface with 1MHz clock support

gives a convenient, standardized digital interface for

configuration as well as telemetry of key parameters

including output voltage, output current, and internal

die temperature. Response to fault conditions can

be set to restart, latch off, or ignore, depending

on system requirements. Two, three, and four

TPS546C25 devices can be interconnected to provide

up to 140A on a single output.

The device has an option to overdrive the internal 5V

LDO with an external 5V supply through the VDRV

and VCC pins to improve efficiency, reduce power

dissipation, and enable start-up with a lower input

voltage.

The TPS546C25 is a lead-free device and is RoHS

compliant without exemption.