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.