1 Features

• Designed for reliability in rugged applications

– Wide input voltage range of 6 V to 120 V

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

– Fixed 3-ms internal soft-start timer

– Peak and valley current-limit protection

– Input UVLO and thermal shutdown protection

• Suited for scalable industrial power supplies and

battery packs

– Low minimum on and off times of 50 ns

– Adjustable switching frequency up to 1 MHz

– Diode emulation for high light-load efficiency

– Auto mode with low quiescent current (< 10 μA)

– FPWM for fly-buck converter capability

– 3-μA shutdown quiescent current

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

LM5017, and LM34927

• Integration reduces solution size and cost

– COT mode control architecture

– Integrated 1.9-Ω NFET buck switch

– Integrated 0.71-Ω NFET synchronous rectifier

– 1.2-V internal voltage reference

– No loop compensation components

– Internal VCC bias regulator and boot diode

– Open-drain power-good indicator

– SOIC PowerPAD™ integrated circuit package

2 Applications

• Communications – brick power module

• Industrial battery pack (≥ 10 S)

• Battery pack – e-bike/e-scooter/LEV

3 Description

The LM5169 and LM5168 synchronous buck

converters are designed to regulate over a wide input

voltage range, minimizing the need for external surge

suppression components. A minimum controllable on

time of 50 ns facilitates large step-down conversion

ratios, enabling the direct step-down from a 48-V

nominal input to low-voltage rails for reduced system

complexity and solution cost. The LM516x operates

during input voltage dips as low as 6 V, at nearly

100 duty cycle if needed, making it 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 LM5169 delivers up to 0.65-A of output

current and the LM5168 delivers up to 0.3-A of output

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

provides nearly constant switching frequency with

excellent load and line transient response. The

LM516x is available in FPWM or auto mode versions.

FPWM mode provides forced CCM operation across

the entire load range supporting isolated fly-buck

converter applications. Auto mode enables ultra-low

IQ and diode emulation mode operation for high lightload

efficiency.