RT/SYNC

VIN

BOOT1

EN/UVLO

VOUT

AGND

CSG

SS

CS

PGND

VOSNS

HDRV1

SW1

COMP

LM5175

LDRV1

LDRV2

HDRV2

BOOT2

SW2

Enable

VCC

VCC

VCC

SLOPE

PGOOD

Power Good

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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.

LM5175

SNVSA37A – OCTOBER 2015 – REVISED MAY 2016

LM5175 42-V Wide VIN Synchronous 4-Switch Buck-Boost Controller

1

1 Features

1

•

Single Inductor Buck-Boost Controller for Step-

Up/Step-Down DC/DC Conversion

•

Wide VIN Range: 3.5 V to 42 V, 60 V Maximum

•

Flexible VOUT Range: 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

•

Selectable CCM or DCM with Pulse Skipping

•

Available in HTSSOP-28 and QFN-28 Packages

•

Create a Custom Design Using the LM5175 with

the WEBENCH Power Designer

2 Applications

•

Automotive Start-Stop Systems

•

Backup Battery and Supercapacitor Charging

•

Industrial PC Power Supplies

•

USB Power Delivery

•

LED Lighting

3 Description

The LM5175 is a synchronous four-switch buck-boost

DC/DC controller capable of regulating the output

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

LM5175 operates over a wide input voltage range of

3.5 V to 42 V (60 V maximum) to support a variety of

applications.

The LM5175 employs 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 LM5175

features selectable Continuous Conduction Mode

(CCM) or Discontinuous Conduction Mode (DCM)

operation, 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

ORDER NUMBER

PACKAGE

BODY SIZE

LM5175PWP

HTSSOP-28

9.7 mm x 4.4 mm

LM5175RHF

QFN-28

4.0 mm x 5.0 mm

4 Simplified Schematic