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.