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.