1 Features
• Fixed-frequency, internally compensated,
advanced current mode (ACM) control
• Integrated 6.5-mΩ and 2-mΩ MOSFETs
• 4-V to 18-V input voltage range
• 0.5-V to 7-V output voltage range
• True differential remote sense amplifier (RSA)
• Three selectable PWM ramp options to optimize
the control loop performance
• Five selectable switching frequencies: 500 kHz,
750 kHz, 1 MHz, 1.5 MHz, and 2.2 MHz
• Synchronizable to an external clock
• 0.5 V, ±0.5% voltage reference accuracy over full
temperature range
• 1-ms, 2-ms, 4-ms, and 8-ms selectable soft-start
times
• Monotonic start-up into prebiased outputs
• Selectable current limits to support 25-A and 20-A
operation
• Enable with adjustable input undervoltage lockout
• Power-good output monitor
• Output overvoltage, output undervoltage, input
undervoltage, overcurrent, and overtemperature
protection
• –40°C to 150°C operating junction temperature
• 2.5-mm × 4.5-mm, 17-pin WQFN-HR package with
0.5-mm pitch
• Lead-free (RoHS compliant)
• Pin compatible with the 20 A-TPS543B22 , 16 ATPS543A26
and 12 A-TPS543A22
• WEBENCH® and SIMPLIS models available

2 Applications
• Wireless and wired communications infrastructure
equipment
• Optical and fiber networks
• Test and measurement
• Medical and healthcare

3 Description
The TPS543B25 is a high-efficiency 18-V, 25-A
synchronous buck converter employing an internally
compensated, fixed-frequency advanced current
mode (ACM) control architecture, which while always
operating under FCCM, generates output voltages
from 0.5 V to 7 V. The device is capable of
providing high efficiency while operating at a switching
frequency up to 2.2 MHz, making it optimal for
designs requiring a small solution size. The fixed
frequency controller can operate from 500 kHz to
2.2 MHz 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 UVLO through the EN pin, and a full suite
of fault protections.
The TPS543B25 is available in a small 2.5-mm × 4.5-
mm HotRod™ WQFN-FCRLF package.