1 Features

• Fixed-frequency, internally-compensated,

advanced current mode (ACM) control

• Integrated 6.5mΩ and 2mΩ MOSFETs

• 4V to 18V input voltage range

• 0.5V to 7V output voltage range

• True differential remote sense amplifier (RSA)

• Three selectable PWM ramp options to optimize

the control loop performance

• Five selectable switching frequencies: 500kHz,

750kHz, 1MHz, 1.5MHz, and 2.2MHz

• Synchronizable to an external clock

• 0.5V, ±0.5% voltage reference accuracy over full

temperature range

• 1ms, 2ms, 4ms, and 8ms selectable soft-start

times

• Monotonic start-up into prebiased outputs

• Selectable current limits to support 25A and 20A

operation

• Enable with adjustable input undervoltage lockout

• Power-good output monitor

• Output overvoltage, output undervoltage, input

undervoltage, overcurrent, and overtemperature

protection

• –55°C to 150°C operating junction temperature

• 2.5mm × 4.5mm, 17-pin WQFN-FCRLF package

with 0.5mm pitch

• Lead-free (RoHS compliant)

• Pin compatible with the 20A - TPS543B22, 16A -

TPS543A26, and 12A - TPS543A22

• SIMPLIS models available

• Create a custom design using the TPS543B25E

with the WEBENCH® Power Designer

2 Applications

• Avionics

• Electronic warfare

• Software defined radio

• Seeker front end

3 Description

The TPS543B25E is a high-efficiency, 18V, 25A,

synchronous buck converter. The device employs

an internally compensated, fixed-frequency, ACM

control architecture, which while always operating

under forced continuous conduction mode (FCCM),

generates output voltages from 0.5V to 7V. The

device is capable of providing high efficiency while

operating at a switching frequency up to 2.2MHz,

making the device an excellent choice for designs

requiring a small design size. The fixed frequency

controller can operate from 500kHz to 2.2MHz

and can be synchronized to an external clock

using the SYNC pin. Additional features include a

high accuracy voltage reference, two-wire remote

sense, selectable soft-start times, monotonic startup

into prebiased outputs, selectable current limits,

adjustable undervoltage lockout (UVLO) through the

EN pin, and a full suite of fault protections.

The TPS543B25E is available in a small, 2.5mm ×

4.5mm, HotRod™ WQFN-FCRLF package.