1 Features

? Wide input range from 3.5 V to 60 V (85-V

absolute maximum)

– Minimum 2.8 V when V(BIAS) > 3.5 V

? Output voltage from 3.3 V to 60 V

? Low shutdown IQ of 3 μA

? Low operating IQ of 60 μA

? 3 reverse current limit accuracy for precise

charging currents

? Average input and output current monitor or limiter

? Dynamic output voltage tracking for PWM or

analog input signals

? Power save mode (PSM) selectable for high light

load efficiency

? Two integrated high-voltage supply LDOs with

automatic selection

? 2-A peak current logic level gate driver

– Integrated bootstrap diode

– Bootstrap overvoltage and undervoltage

protection

? Fixed frequency across all operating modes

(boost, buck-boost, buck)

– Forced PWM mode selectable

– Switching up to 600 kHz for small solution and

component size

– External clock synchronization

? Spread spectrum operation selectable

? Adjustable undervoltage protection

? Hiccup overcurrent and short protection

2 Applications

? Non-isolated DC/DC supply (merchant DC/DC,

remote radio unit, motor drive control)

? Backup power systems (battery backup, fire

safety)

? Industrial PC (single board computer)

? Medical PSU (oxygen concentrator)

? Power over ethernet (router)

? Solar power (solar charge controller)

3 Description

The LM5177 is a four switch buck-boost controller.

The device provides a regulated output voltage if

the input voltage is higher, equal, or lower than the

adjusted output voltage. In power safe mode, the

device supports high efficiency with low output loads

due to its low quiescence currents. The LM5177

runs at a fixed switching frequency, which can be

set through the RT or SYNC pin. The switching

frequency remains the same during buck, boost, and

buck-boost operation. The integrated and optional

average current monitor can help monitor and limit

input and output current of the LM5177. This feature

also supports charging backup power elements, like

batteries or capacitors, with constant current (CC) and

constant voltage (CV).