1 Features

• AEC-Q100 qualified for automotive applications:

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

• Functional Safety-Compliant

– Developed for functional safety applications

– Documentation available to aid ISO 26262

system design planned

– Systematic capability up to ASIL D

– Hardware capability up to ASIL C

– Analog built-in-self-test at start-up

– Redundant and fast (0.35μs) VOUT monitor

– Feedback path failure detection

– Redundant temperature sensor

– Excellent pin FMEA and pin spacing

• Wide input voltage range: 3V to 36V

• Designed for low EMI requirements

– Facilitates CISPR 25 class 5 compliance

– Mode pin configurable ±5% or ±10% dualrandom

spread spectrum reducing peak

emissions

– Enhanced HotRod™ QFN package with

symmetrical pinout

– Switching frequency from 300kHz to 2.2MHz

– Pin-configurable 400kHz and 2.1MHz

– Pin-configurable AUTO or FPWM operation

– Dual phase capable up to 16A for high current

designs

– Pin-pin with 65V LM686x5-Q1 family of devices

• Low minimum on time: 40ns (maximum)

• High-efficiency power conversion at all loads

– > 94.65% peak efficiency at 12VIN, 5VOUT,

400kHz

– 3.0μA PFM no-load input current

• High power density

– Internal compensation, current limit, and TSD

– 3.6mm × 2.6mm, wettable flank, 20-pin

package

– ϴJA = 24.0°C/W (LM654x0-Q1EVM)

• Create a custom design using the LM684x0-Q1

with the WEBENCH® Power Designer

2 Applications

• Advanced driver assistance systems (ADAS)

• Automotive infotainment and cluster

• Hybrid, electric, and powertrain systems

3 Description

The LM684x0-Q1 are a family of automotive buck

converters designed for high efficiency, high power

density, and ultra-low electromagnetic interference

(EMI). The converters operate over a wide input

voltage range of 3V to 36V (42V tolerant) The

LM684x0-Q1 is dual phase capable by simply

connecting the compensated error signal between

the primary and secondary device. The LM684x0-

Q1 comes with pin selectable fixed output voltages

of 3.3V and 5V or in adjustable configuration.

The low EMI operation is enabled with minimized

loop inductance and optimized switch node slew

rate. A pin-selectable ±5% or ±10% dual-random

spread spectrum (DRSS) significantly reduces peak

emissions through a combination of triangular and

pseudo-random modulation while keeping output

voltage ripple very low. The current-mode control

architecture with a 30ns typical minimum on-time

allows high conversion ratios at high frequencies

coupled with a fast transient response and excellent

load and line regulation.

The LM684x0-Q1 buck converters are specifically

intended for functional safety relevant applications.

An array of safety features including ABIST at startup,

redundant and fast VOUT monitoring, feedback

path failure detection, redundant temperature sensor,

thermal shutdown, and current limiting significantly

reduce the residual failure-in-time (FIT).