1 Features

• Functional Safety-Capable

– Documentation available to aid IEC 61508-2

system design

• Versatile synchronous buck converter family

– Wide input voltage range of 3.5V to 65V

– 4A, 6A, and 8A output current options

– Adjustable output voltage from 0.8V to 60V, or

fixed output options of 3.3V and 5V

– 150°C maximum junction temperature

– 36ns tON(min) for high step-down conversion

• ZEN 1 switcher technology

– Facilitates CISPR 11 or 32 Class B compliance

– Enhanced HotRod™ QFN (eQFN) package with

symmetrical pinout design and minimal LLOOP

– Spread Spectrum (DRSS) and switching slewrate

control reduce peak emissions

– Switching frequency from 300kHz to 2.2MHz

– AUTO, FPWM, or SYNC operation

• High efficiency across the full load current range

– 95% at 48VIN, 12VOUT, 8A, 400kHz

– Multiphase stackable for higher output current

– Dual-input VCC subregulator with BIAS option

– VIN sleep quiescent current as low as 1.8μA

• Improved reliability with optimized pinout design

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

– VIN to PGND pin clearance of 1.1mm

• Create a custom design using the LM65680/60/40

converter with WEBENCH® Power Designer

2 Applications

• Industrial automation, test and measurement

• Medical imaging systems, energy infrastructure

• Enterprise systems, wireless infrastructure

3 Description

The LM65680/60/40 is a synchronous buck DC/DC

converter offered from a family of devices with ZEN 1

technology designed for low EMI, high power density,

and excellent conversion efficiency. Integrated power

MOSFETs with low RDS(on) enable up to 8A of output

current across a wide input voltage range of 3.5V to

65V.

Phase stackable with synchronized interleaving,

the peak current-mode control architecture of the

LM65680/60/40 supports accurate current sharing

with paralleled phases for higher output currents.

AUTO mode enables frequency foldback during lightload

operation, giving high light-load efficiency and a

no-load input current as low as 2.2μA, which extends

operating run-time in battery-powered systems.

A high-side switch minimum on-time of 36ns facilitates

large step-down ratios, enabling the direct conversion

from 24V or 48V inputs to low-voltage rails for

reduced system cost and complexity. The package

has several NC pins between critical power pins,

which improve the Failure Modes and Effects Analysis

(FMEA) result.