1 Features

? Configured for a wide range of applications

– 3.8V to 18V input voltage range

– Up to 5A (TPS543521), 4A (TPS543421), 3A

(TPS543321) continuous output current

– 0.6V ±1% reference voltage (–40°C to 150°C)

– 70ns and 114ns minimum switching on and

off-time

– 8us maximum switching on-time

– 98% maximum duty cycle

? High efficiency

– Integrated 47mΩ and 21mΩ MOSFETs

– Low quiescent current of 28uA (typical)

? Ease of use and small design size

– Peak current control mode with internal

compensation

– 200kHz to 2.2MHz selectable frequency

– Synchronizable to an external clock (support

phase shift): 200kHz to 2.2MHz

– Selectable PFM / FCCM at light load condition

– Selectable adjustable soft-start time,

power-good indicator function

– Good EMI performance with frequency spread

spectrum and optimized pinout

– Hiccup overcurrent (OC) limit for both high-side

and low-side MOSFETs

– Non-latched protections for over temperature

protection (OTP), overcurrent protection (OCP),

overvoltage protection (OVP), undervoltage

protection (UVP), and undervoltage lockout

(UVLO)

– Integrated bootstrap capacitor to support

single-layer PCB layout

– –40°C to 150°C operating junction temperature

– 1.5mm × 2.0mm QFN package

? Create a custom design with the TPS543x21 using

the WEBENCH? Power Designer

2 Applications

? Medical and healthcare, building automation, test

and measurement

? Multifunction printers, enterprise projectors

? Portable electronics, connected peripherals

? Wired networking, wireless infrastructure

? Distributed power systems with 5V, 12V input

3 Description

The TPS543x21 is a high-efficiency, high-voltage

input, and easy-to-use, synchronous buck converter

with high design flexibility. With the wide operating

input voltage range of 3.8V to 18V, the TPS543x21

is designed for systems powered from 5V, 12V powerbus

rails. The device supports up to 5A, 4A, 3A

continuous output current and 98% maximum duty

cycle.

TPS543x21 uses fixed frequency peak current control

with internal compensation for fast transient response

and good line and load regulation. With the optimized

internal loop compensation, the device eliminates the

need for external compensation over a wide output

voltage range and switching frequency. Integrated

bootstrap capacitor helps achieve single layer PCB

and reduce external component count.