The STMicroelectronics STTH8L06G is a standard fast-recovery diode rated for 8 A average rectified current and 600 V DC reverse voltage, in a D2PAK (TO-263-3) surface-mount package. Its reverse recovery time of 105 ns places it squarely in the fast-recovery class — fast enough for continuous-conduction-mode PFC boost stages, output rectification in flyback converters, and snubber clamping in motor drives, without the higher Vf penalty of an ultrafast device.
1.3 Vf at 8 A — thermal budget in the D2PAK
Forward voltage is 1.3 V at the full 8 A rated current, which puts conduction losses at about 10.4 W. The D2PAK's exposed tab on the bottom carries most of the heat — without a proper via-stitched thermal land on the PCB, junction temperature will climb past the 175 °C maximum under sustained full load. The 8 µA reverse leakage at 600 V is low for a 600 V-class device, which helps in standby-light-load efficiency.
STMicroelectronics no longer manufactures this part as a standard catalogue item, and no direct-replacement order code is listed on the official record. No pin-compatible drop-in has been validated as an official second source; any substitution requires a design review of the switching characteristics.