1200 V fast recovery diode for automotive high-voltage rails
The STMicroelectronics STTH112UFY is a 1200 V, 1 A fast recovery rectifier in the SMBflat (DO-221AA) package, qualified to AEC-Q101 for automotive use.
75 ns trr — what it means for switching loss
The 75 ns trr is specified as a Fast Recovery diode (≤ 500 ns, > 200 mA Io). In a continuous-current-mode PFC running at 100 kHz, that recovery charge is low enough to keep the MOSFET turn-on loss within the thermal budget without requiring a SiC diode. The 1.9 V forward drop at 1 A is a trade-off — higher than a standard 600 V ultrafast but justified by the 1200 V blocking rating.
Automotive grade and junction temperature range
The 5 µA reverse leakage at 1200 V is a room-temperature typical — expect that to rise with junction temperature, so the thermal design must account for leakage-induced power at high line.
The SMBflat (DO-221AA) is a low-profile surface-mount package with flat leads — no J-bend, no gull-wing. It sits flush on the PCB, which helps thermal transfer to the board copper but makes visual solder-joint inspection trickier than a standard SMB. The flat leads also reduce the risk of tombstoning during reflow. The base product number is STTH112; the UFY suffix specifies the SMBflat package and the ECOPACK®2 lead-free finish.