The TIP42A is a PNP bipolar power transistor in a TO-220-3 through-hole package, rated for 60 V collector-emitter breakdown and 6 A continuous collector current. The saturation voltage is 1.5 V maximum at 6 A with 600 mA of base drive. Minimum DC current gain (hFE) is 15 at 3 A collector current and 4 V Vce.
The TIP42A carries an official lifecycle status of Obsolete. For a new design, consider a modern PNP power transistor in a TO-220 package with similar voltage and current ratings — the 60 V, 6 A ceiling is a common tier, and several manufacturers offer active alternatives. The TIP42A remains a viable replacement for repair and legacy BOM lines where the original part is specified.
TO-220 package — through-hole, heatsink-ready
The TO-220-3 through-hole package allows bolting the metal tab to a heatsink with an insulating washer. The TO-220 package is hand-solderable with a standard iron — no hot-air or reflow profile needed. For a hobbyist or repair bench, this is a friendly footprint: the leads are robust, the tab gives good thermal contact to a heatsink, and you can socket it if needed.