1 Features

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

step-down DC/DC conversion

• Wide VIN: 4.2 V (2.5 V with bias) to 30 V (42-V

maximum)

• Flexible VOUT: 0.8 V to 30 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 lnput UVLO and soft start

• Power good and output overvoltage protection

• Available in QFN-28 package

• Create a custom design using the LM34936 with

the WEBENCH Power Designer

2 Applications

• Industrial PC power supplies

• USB power delivery

• Battery-powered systems

• LED Lighting

3 Description

The LM34936 is a synchronous four-switch buckboost

DC/DC controller capable of regulating the

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

The LM34936 operates over a wide input voltage

range of 4.2 V to 30 V (42-V absolute maximum) to

support a variety of applications.

The LM34936 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 cycleby-

cycle current limiting, input undervoltage lockout

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

thermal shutdown. In addition, the LM34936 features

optional average input or output current limiting,

optional spread spectrum to reduce peak EMI, and

optional hiccup mode protection in sustained overload

conditions.