What this dual Schottky does in the power stage
The STMicroelectronics STPS20L60CTN is a 60 V, 20 A dual Schottky rectifier in a common-cathode configuration, packaged in a through-hole TO-220AB with narrow leads. The common-cathode pair is typically used in center-tapped secondary rectification for switch-mode power supplies, OR-ing diodes in redundant power architectures, or as a freewheeling clamp in motor-drive and inverter stages where the Schottky's fast recovery (≤500 ns, >200 mA) and low Vf keep switching losses down.
ST officially lists the STPS20L60CTN as obsolete. There is no successor order code in the record, so a direct drop-in from ST is not published. For a production BOM that was qualified on this exact part number, the path is either sourcing remaining factory-origin inventory through independent distribution (date-code and lot traceability verified at quote) or qualifying a functional substitute with the same common-cathode TO-220AB footprint. The reverse leakage at 60 V is 350 µA, and the junction temperature maxes at 150°C — these are the parameters a replacement must meet or exceed.
Package and mounting — the narrow-lead detail
The STPS20L60CTN uses the TO-220AB narrow-leads variant (supplier device package), not the standard-width TO-220AB. The lead spacing is tighter, which means the hole pattern on the PCB or the heatsink clip must match the narrow dimension. It is a through-hole device in a TO-220-3 case, shipped in tube form. If a replacement part uses standard-width leads, the mechanical fit will not work without bending or re-drilling.