1 Features

• Configured for rugged industrial applications:

– 4.3V to 60V input voltage range

– 3.5A continuous output current

– 75ns minimum switching on time

– 400kHz switching frequency

– Frequency spread spectrum (PFM variant)

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

– 96% maximum duty cycle

– Monotonic start-up with prebiased output

– Short-circuit protection with hiccup mode

– Precision enable

– ±1% tolerance voltage reference at room

temperature

• Small design size and ease of use:

– Integrated synchronous rectification

– Internal compensation for ease of use

– SOT-23 package

• Create a custom design using the LMR51635 with

the with the WEBENCH® Power Designer

2 Applications

• Major appliances

• PLC, DCS, and PAC

• Smart meters

• General purpose wide VIN power supplies

3 Description

The LMR51635 is a wide-VIN, easy-to-use,

synchronous buck converter capable of driving up to

3.5A load current. With a wide input range of 4.3V

to 60V, the device is designed for a wide range of

industrial applications for power conditioning from an

unregulated source.

The LMR51635 operates at 400kHz switching

frequency to support use of relatively small inductors

for an optimized design size. The device has pulse

frequency modulation (PFM version) to realize high

efficiency at light load. Soft-start and compensation

circuits are implemented internally, which allow the

device to be used with minimal external components.

The device has built-in protection features, such as

cycle-by-cycle current limit, hiccup mode short-circuit

protection, and thermal shutdown in case of excessive

power dissipation.