LM5175RHFR

Overview

The LM5175RHFR is a synchronous four-switch buck-boost DC/DC controller manufactured by Texas Instruments. It supports a wide input voltage range of 3.5 V to 42 V, with a maximum rating of 60 V. The device regulates output voltages from 0.8 V to 55 V and can drive external MOSFETs for output currents up to 20 A. It features an adjustable switching frequency between 100 kHz and 600 kHz, which can be synchronized to an external clock. The component operates within a junction temperature range of -40°C to +125°C and is housed in a 28-pin HTSSOP package.

Feature Summary

• Synchronous four-switch topology enables efficient buck, boost, and transition mode operation across varying input and output voltage conditions.
• Integrated high-current gate drivers provide 2 A source and sink capability for driving external power MOSFETs.
• Comprehensive protection suite includes cycle-by-cycle current limiting, input undervoltage lockout, output overvoltage protection, and thermal shutdown.
• Flexible control options allow for selectable continuous or discontinuous conduction modes, spread spectrum dithering, and programmable soft-start.

Applications

• Automotive infotainment systems and body electronics
• Industrial motor drives and PLC power supplies
• USB Power Delivery (PD) adapters and chargers
• LED lighting drivers requiring wide input ranges

Procurement Notes

Verify the suffix RHFR indicates the HTSSOP-28 package variant when sourcing. Confirm RoHS compliance and manufacturing date codes against specific project requirements. Ensure ESD handling protocols are followed during assembly due to the sensitivity of the CMOS control circuitry. Cross-reference datasheet revisions to confirm pinout consistency if replacing older inventory batches.

Selection Notes

Select this controller for applications requiring a single-inductor solution that handles significant voltage transients without mode switching losses. Evaluate thermal performance based on the expected load current and PCB copper area, as the HTSSOP-28 package relies on the exposed pad for heat dissipation. Consider the need for external compensation components to stabilize the feedback loop under varying line and load conditions.

Part Context

The LM5175RHFR belongs to the LM5175 family of wide-input-voltage buck-boost controllers. It shares functional similarities with the LM5176, which offers a higher 55 V input rating, and the LM5177, designed for bidirectional power flow. This specific part is optimized for standard unidirectional automotive and industrial applications where a 42 V nominal system voltage is prevalent.

Replacement Considerations

LM5175RHFT: Identical electrical specifications but packaged in a 28-VQFN form factor instead of HTSSOP. LM5175PWPR: Same functionality in an HTSSOP-28 package but may differ in moisture sensitivity level or reel quantity. LM5176RHFR: Higher voltage tolerance up to 55 V; verify input supply limits before substitution.