1 Features
• Wide input range from 3.5V to 60V (85V absolute
maximum)
– Minimum 2.8V when V(BIAS) > 3.5V
• Output voltage from 3.3V to 60V
• Low shutdown IQ of 3μA
• Low operating IQ of 60μA
• 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
• 2A 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 600kHz 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 save 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).