2 A adjustable buck in an 8-SOIC footprint
The TPS54233D is a 2 A continuous-output, step-down (buck) switching regulator from Texas Instruments' SWIFT™ and Eco-Mode™ series. Switching at a fixed 300 kHz, the part uses an external Schottky catch diode — the internal FET handles the high-side switch, but the low-side is external because synchronous rectification is not implemented. This keeps the BOM simple for cost-sensitive rails where the efficiency gain of a synchronous FET isn't justified.
Thermal and package constraints for the layout
The output is adjustable via an external resistor divider, with a 0.8 V internal reference. At the maximum output of 25 V, the duty cycle approaches 90 % at the minimum input voltage — the 300 kHz switching frequency keeps the inductor physically small, but the off-time at high duty cycles is short enough that the bootstrap capacitor must be sized correctly for the high-side driver.