1 Features

• AEC-Q100 qualified

– Temperature grade 1: –40°C to 125°C ambient

operating temperature range

• Functional Safety-Capable

– Documentation available to aid functional safety

system design

• Configured for rugged industrial applications

– 4V to 65V input voltage range

– Input transient protection up to 70V

– 300mA continuous output current

– 80ns minimum switching on time

– Fixed 400kHz switching frequency

– –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

• Small design size and ease of use

– Integrated synchronous rectification

– Internal compensation for ease of use

• Various options in pin-to-pin compatible package

– PFM and forced PWM (FPWM) options

• Pin-to-pin compatible with the LMR16006Y-Q1,

LM2842-Q1, LMR50410-Q1, and TPS560430-Q1

• Create a custom design using the LMR51603-Q1

with the WEBENCH® Power Designer

2 Applications

• Body electronics and lighting

• Infotainment and cluster

• Advanced driver assistance systems (ADAS)

3 Description

The LMR51603-Q1 is a wide-VIN, easy-to-use,

synchronous buck converter capable of driving up to

300mA load current. With a wide input range of 4V

to 65V, the device is designed for a wide range of

industrial applications for power conditioning from an

unregulated source.

The LMR51603-Q1 operates at 400kHz switching

frequency to support use of relatively small inductors

for an optimized design size. The LMR51603-Q1

has a 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 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.