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:
– Facilitates CISPR 25 class 5 compliance
– Integrated bypass and boot capacitors reduce
EMI
– 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 solution size and low component cost:
– Integrated input bypass capacitors and
bootstrap capacitor reducing EMI
– 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 LMQ664x0-Q1 is the industry smallest 36-V, 3-A
(available in 2-A and 1-A variants) synchronous stepdown
DC/DC converter with an integrated bypass and
bootstrap capacitor 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 LMQ664x0-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
solution 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 LMQ664x0-
Q1 is designed to simplify implementation for a wide
range of automotive end equipment.