1200 V fast recovery diode in a DO-41 axial package
The STTH112 is a 1200 V, 1 A fast-recovery rectifier from STMicroelectronics, built for hard-switched power stages where reverse recovery charge needs to be low. Its 75 ns trr keeps switching losses in check at frequencies where a standard recovery diode would overheat.
Switching speed and voltage class — the fit decision
The 1200 V blocking voltage gives headroom for 400 VDC bus rails with derating for transients, but the 1 A average current limits the part to low-power auxiliary rails or gate-drive bootstrap supplies — not the main output rectifier of a 100 W+ supply. Forward voltage is 1.9 V maximum at 1 A, which translates to 1.9 W conduction loss at full rated current — a significant thermal load for the DO-41 package.
No successor order code is recorded in the lifecycle entry. For new designs, a pin-compatible fast-recovery diode in the same voltage and current class — such as a 1200 V, 1 A, DO-41 part from another manufacturer — should be qualified.