1 Features

? Functional Safety-Capable

– Documentation available to aid functional safety

system design

? Configured for rugged industrial applications:

– Wide input voltage range: 4V to 36V

– Continuous output current: 2.5A or 3.5A

– ±1.0% tolerance voltage reference at room

temperature

– Minimum switching-on time: 75ns (typical)

– Low quiescent current: 25μA

– Adjustable frequency: 200kHz to 1.1MHz

– Frequency spread spectrum

– Protection features:

? Precision enable input

? Open-drain PGOOD

? VIN undervoltage lockout (UVLO)

? Cycle-by-cycle current limiting

? Short-circuit protection with hiccup mode

? Thermal shutdown

? Small design size and ease of use

– Integrated synchronous rectification

– Internal compensation for ease of use

– WSON-12 package

? PFM and FPWM options in pin-to-pin compatible

package

? Create a custom design using the LMR514x5 with

the WEBENCH? Power Designer

2 Applications

? Major appliances

? PLC, DCS, and PAC

? Test and measurement instrumentation

? Power delivery

3 Description

The LMR514x5 is a wide-VIN, easy-to-use,

synchronous buck converter capable of driving up to

2.5A or 3.5A load current. With a wide input range of

4V to 36V, the device is designed for a wide range of

industrial applications for power conditioning from an

unregulated source.

The LMR514x5 features adjustable switching

frequency from 200kHz to 1.1MHz with an external

resistor, which provides the flexibility to optimize either

efficiency or external component size. The device

has pulse frequency modulation (PFM version) to

realize high efficiency at light load, and forced pulse

width modulation (FPWM version) to achieve constant

frequency, and small output voltage ripple over the full

load range. Soft-start and compensation circuits are

implemented internally, which allows the device to be

used with minimum 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. The LMR514x5 is available in a

WSON-12 package.