The STMicroelectronics STTH16BC065CT is a fast-recovery rectifier diode rated for 650 V reverse voltage and 16 A average forward current per diode, configured as a common-cathode pair in a TO-220-3 package. The through-hole TO-220-3 package simplifies heatsink attachment for the continuous 16 A load.
40 ns trr — the switching-speed edge
The 40 ns reverse recovery time separates this part from a standard-recovery 650 V rectifier. The 3.2 V forward drop at 8 A is the trade-off for fast recovery.
ST lists the STTH16BC065CT as obsolete. For a production BOM that already carries this part, the options are: source remaining factory inventory or qualified surplus through the independent channel, or qualify a cross from another manufacturer. The common-cathode TO-220-3 footprint is widely used, so several 650 V, 16 A fast-recovery dual diodes exist — but each candidate must be evaluated for trr, Vf, and thermal performance against the original design's margin.
Through-hole TO-220-3 — mounting and thermal design
The TO-220-3 package (Supplier Device Package TO-220) mates the common-cathode pair's shared cathode to the metal tab, which is the primary thermal path. In a typical PFC boost layout, the tab is soldered to a copper island on the PCB or bolted to a heatsink with an insulating pad. The 16 A per diode rating assumes adequate heatsinking — without it, junction temperature will exceed the rated maximum at full load. The through-hole leads handle the mechanical stress of a bolted heatsink better than a surface-mount D²PAK would in high-vibration environments.