Buck-boost controller with wide input range
The LM5175PWPT is a current-mode buck-boost switching regulator controller from Texas Instruments, designed to regulate output voltage above, below, or equal to the input voltage. It drives external N-channel MOSFETs in a four-switch synchronous buck-boost topology. The supply voltage range of 3.5 V to 42 V covers common automotive and industrial rails — a 12 V nominal system with cold-crank dips to 4 V and load-dump excursions to 40 V stays within the operating envelope without external clamping. Switching frequency is programmable from 100 kHz to 600 kHz and can be synchronised to an external clock via the Clock Sync pin, which lets the designer place switching harmonics away from sensitive frequency bands in mixed-signal boards.
Package and thermal: 28-PowerTSSOP with exposed pad
The exposed pad is on the bottom; the reflow profile should follow the solder paste manufacturer's recommendation for the pad size, typically a 50×50 mil stencil aperture centred on the pad.
Temperature grade and control features
Built-in control features include Enable, Frequency Control, Power Good flag, and Soft Start — the soft-start pin lets the designer ramp the output voltage over a programmed interval to limit inrush current into the output capacitor bank. Synchronous rectification is integrated into the control scheme, meaning the low-side MOSFETs are actively driven to conduct during their respective phases rather than relying on the body diode, which cuts conduction loss by roughly 20-30 % compared to an asynchronous design at the same output current.
No pin-compatible second-source is listed on the manufacturer's cross-reference — the part is sole-sourced from Texas Instruments.