1 Features

? AEC-Q100 qualified for automotive applications

– Device temperature grade 1: –40°C to +125°C

ambient operating temperature

? Functional Safety-Capable

– Documentation available to aid functional safety

system design

? Versatile synchronous buck DC/DC converter

– Wide input voltage range of 3V to 36V with

tolerance for load-dump transients up to 42V

– 4A and 6A options available

– 1% accurate, fixed 3.3V, 5V, or adjustable

output voltage from 1V to 95% VIN

– 150°C maximum junction temperature

– Fixed 2.1MHz switching frequency (adjustable

from 200kHz to 2.2MHz using a SYNC signal)

? Improved reliability with optimized pinout design

and clearance for short-circuit-to-adjacent-pin test

? Designed for low EMI requirements

– Enhanced HotRod? QFN package with dual

input paths reduces switch-node ringing

– Pin-configurable spread spectrum modulation

– Selectable FPWM or PFM mode at light loads

? High efficiency across the full load range

– 92.5% at 13.5VIN, 5VOUT, 6A, 2.1MHz

– 7μA typical at 3.3VOUT no-load input current

– 0.6μA typical shutdown quiescent current

– 0.6V typical dropout at full load

– External bias option for improved efficiency

? Create a custom regulator design using the

LM644x0-Q1 with WEBENCH? Power Designer

2 Applications

? Automotive infotainment and cluster: head unit,

media hub, USB charge, display

? Automotive ADAS and body electronics

3 Description

The LM644x0-Q1 derives from a family of automotive,

synchronous, buck, DC/DC converters with excellent

efficiency and ultra-low IQ. With integrated high-side

and low-side MOSFETs, up to 6A of output current is

delivered over a wide input voltage range from 3V to

36V, with support for load-dump transients up to 42V.

The converter implements soft recovery from dropout

to eliminate overshoot on the output.

The LM644x0-Q1 incorporates numerous features

for excellent EMI performance, including spreadspectrum

frequency modulation, a low-EMI Enhanced

HotRod QFN package that mitigates switch-node

ringing, and a symmetrical pinout for excellent input

capacitor placement. The switching frequency is

synchronizable between 200kHz and 2.2MHz to avoid

sensitive frequency bands, while optimizing efficiency

or design size based on the specific requirements of

the application.

PFM mode enables frequency foldback during

light-load operation, allowing an unloaded current

consumption of only 7μA (typical) and high light-load

efficiency. A seamless transition between PWM and

PFM modes, along with low MOSFET on-resistances

and an external bias input, provides exceptional

efficiency and thermal performance across the entire

load range. The package has several NC pins

between critical power pins, which improve the Failure

Modes and Effects Analysis (FMEA) result.