3A buck regulator in a through-hole TO-220-5
The Texas Instruments LM2576T-12 is a SIMPLE SWITCHER® step-down (buck) regulator delivering a fixed 12V output at up to 3A. It switches at 52 kHz, a low frequency that keeps switching losses down but calls for a larger inductor than a modern 500 kHz part would. The through-hole TO-220-5 package bolts to a heatsink or a copper island on the PCB — the tab is the output switch node, so the thermal pad area needs clearance from ground.
NRND — plan a replacement now
Input range and thermal envelope
The input range spans 4V to 40V, covering unregulated DC rails from 5V to 24V supplies. The 52 kHz switching frequency is fixed; the regulator does not support synchronisation to an external clock, so it is not a fit for noise-sensitive mixed-signal boards where the fundamental and its harmonics must be shifted away from a sensitive band.