LM5176 55-V Wide VIN Synchronous 4-switch Buck-boost Controller

1 Features

• Functional Safety-Capable

– Documentation available to aid functional safety

system design

• Single inductor buck-boost controller for step-up/

step-down DC/DC conversion

• Wide VIN: 4.2 V (2.5 V with bias) to 55 V (60 V

maximum)

• Flexible VOUT: 0.8 V to 55 V

• VOUT short protection

• High efficiency buck-boost transition

• Adjustable switching frequency

• Optional frequency sync and dithering

• Integrated 2-A MOSFET gate drivers

• Cycle-by-cycle current limit and optional hiccup

• Optional input or output average current limiting

• Programmable input UVLO and soft start

• Power Good and output overvoltage protection

• Available in HTSSOP-28 and QFN-28 packages

• Create a custom design using the LM5176 with the

WEBENCH Power Designer

2 Applications

• Industrial PC power supplies

• USB power delivery

• Battery-powered systems

• LED lighting

3 Description

The LM5176 is a synchronous four-switch buck-boost

DC/DC controller capable of regulating the output

voltage at, above, or below the input voltage. The

LM5176 operates over a wide input voltage range of

4.2 V to 55 V (60-V absolute maximum) to support a

variety of applications.

The LM5176 uses current-mode control both in

buck and boost modes of operation for superior

load and line regulation. The switching frequency

is programmed by an external resistor and can be

synchronized to an external clock signal.

The device also features a programmable soft-start

function and offers protection features including cycle-

by-cycle current limiting, input undervoltage lockout

(UVLO), output overvoltage protection (OVP), and

thermal shutdown. In addition, the LM5176 features

optional average input or output current limiting,

optional spread spectrum to reduce peak EMI, and

optional hiccup mode protection in sustained overload

conditions.

Device Information

PART NUMBER

PACKAGE

BODY SIZE

LM5176

HTSSOP (28)

9.70 mm × 4.40 mm

QFN (28)

5.00 mm × 4.00 mm

RT/SYNC

VIN

BOOT1

EN/UVLO

VOUT

AGND

CSG

SS

CS

PGND

VOSNS

HDRV1

SW1

COMP

LM5176

LDRV1

LDRV2

HDRV2

BOOT2

SW2

Enable

VCC

VCC

VCC

SLOPE

PGOOD

Power Good

Simplified Schematic

LM5176

SNVSAI1D – JUNE 2017 – REVISED AUGUST 2021

An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,

intellectual property matters and other important disclaimers. PRODUCTION DATA.