Wide-input buck controller for industrial and automotive rails
The LM25117PSQE/NOPB is a current-mode buck controller from Texas Instruments, designed to step down a 4.5V to 42V input rail to a regulated output using an external MOSFET pair. With synchronous rectification built into the control logic, it targets efficiency-sensitive designs — the external low-side FET recovers body-diode conduction losses that a freewheeling diode would otherwise burn as heat. Switching frequency is programmable up to 750 kHz, letting the designer trade inductor size against switching loss.
Temperature grade and operating envelope
The 42V absolute-max input means it survives 36V truck systems and 24V industrial rails with margin, and handles load-dump transients typical in 12V automotive without an external clamp — the internal circuitry's abs-max rating covers the surge.