1 Features

? Functional Safety-Capable

– Documentation available to aid functional safety

system design

? AEC-Q100-qualified for automotive applications:

– Temperature grade 1: –40°C to +125°C, TA

? Optimized for low EMI requirements:

– Dual random spread spectrum reduces peak

emissions

– Enhanced HotRod? QFN package minimizes

switch node ringing

? Greater than 85 efficiency at 1 mA

? Designed for automotive applications:

– Junction temperature range: –40°C to +150°C

– NC pin between critical pins for better reliability

– Best in-class pin FMEA

– Supports 42-V automotive load dump transients

– Supports 3-VIN for automotive cold crank

? Miniature design size and low component cost:

– 2.6-mm × 2.6-mm enhanced HotRod QFN

package with wettable flanks

– Internal control loop compensation

2 Applications

? Advanced driver assistance systems: radar ECU

? Infotainment and cluster: head unit, eCall

? Body electronics and lighting

3 Description

The LMR664x0-Q1 is a small 36-V, 3-A (available in

2-A and 1-A variants) synchronous step-down DC/DC

converter in an enhanced HotRod QFN package.

This easy-to-use converter supports a wide input

voltage range of 2.7 V to 36 V (after start-up or after

operating) with transients up to 42 V.

The LMR664x0-Q1 is specifically designed to

meet low standby power requirements for alwayson,

automotive applications. Auto mode enables

frequency foldback when operating at light loads,

allowing an unloaded typical current consumption of

1.5 μA at 13.5 VIN and high light load efficiency. A

seamless transition between PWM and PFM modes

along with very low MOSFET ON resistances makes

sure there is exceptional efficiency across the entire

load range. The control architecture (peak current

mode) and feature set are optimized for an ultrasmall

design size with minimal output capacitance.

The device minimizes input filter size by using

dual-random spread spectrum (DRSS), a low-EMI

enhanced HotRod QFN package, and an optimized

pin-out. The MODE/SYNC pin can be used to set or

synchronize the frequency to avoid noise sensitive

frequency bands. There are NC pins between critical

high voltage pins, reducing potential failures (optimal

pin FMEA). The rich feature set of the

LMR664x0-Q1 is designed to simplify implementation

for a wide range of automotive end equipment.