1 Features

• Functional Safety-Capable

– Documentation available to aid functional safety

system design

• Designed for reliability in rugged applications

– 6V to 115V wide input voltage range

– –55°C to +150°C junction temperature range

– Fixed 3ms internal soft-start timer

– Peak and valley current-limit protection

– Input UVLO and thermal shutdown protection

• Designed for scalable industrial power supplies

and battery packs

– 50ns low minimum on and off times

– 1MHz adjustable switching frequency

– Diode emulation for high light-load efficiency

– 10μA sleep current in auto mode

– 3μA shutdown quiescent current

– Pin-to-pin compatible with LM5164, LM5163,

and LM5013

– Similar pinout and functionality to LM5017 and

LM34927

• Integration reduces design size and cost

– COT mode control architecture

– Integrated 1.9Ω NFET buck switch

– Integrated 0.71Ω NFET synchronous rectifier

– 1.2V internal voltage reference

– No loop compensation components

– Internal VCC bias regulator and boot diode

– Open-drain power-good indicator

– Package: SOIC PowerPAD™-8 integrated

circuit package with 1.27mm pin spacing

2 Applications

• Space – solar source, storage

• Aerospace and defense – smart munitions,

actuators

• Avionics – sensor imaging, radar

3 Description

The LM5168E is an extended temperature range,

(–55°C to +150°C) synchronous buck converter

designed to regulate over a wide input voltage range,

minimizing the need for external surge suppression

components. A minimum controllable on time of 50ns

facilitates large step-down conversion ratios, enabling

the direct step-down from a 48V nominal input to

low-voltage rails for reduced system complexity and

design cost. The LM5168E operates during input

voltage dips as low as 6V, at nearly 100% duty cycle

if needed, making the device an excellent choice for

wide input supply range industrial and high cell count

battery pack applications.

With integrated high-side and low-side power

MOSFETs, the LM5168E delivers up to 0.3A of output

current. A constant on-time (COT) control architecture

provides nearly constant switching frequency with

excellent load and line transient response. The

LM5168E is available in the auto mode version,

which enables ultra-low IQ and diode emulation mode

operation for high light-load efficiency.