The STPS1H100AF is a 100 V, 1 A Schottky rectifier from STMicroelectronics, built for low forward voltage drop and fast switching in power conversion stages. The 100 V reverse voltage rating gives headroom for 48 V and 24 V rails, including flyback and PFC output rectification where ringing can push the reverse voltage above the nominal bus. Forward voltage is specified at 770 mV maximum at 1 A — this is the conduction loss at rated current. In a 1 A output rail, that's 770 mW dissipation in the diode alone, which the SMAflat package must sink through the PCB copper.
Switching speed and junction temperature ceiling
Fast recovery ≤ 500 ns at forward currents above 200 mA — this is the reverse recovery time that limits switching losses in continuous-conduction-mode boost or flyback converters. At 100 kHz switching, the recovery loss is small enough to keep the junction within the 175 °C maximum rating.
Package and footprint — SMAflat
The SMAflat package is a low-profile surface-mount variant of the standard SMA. The flat leads reduce the package height compared to a bent-lead SMA, which helps in slim PSU designs. The cathode tab is the main thermal path — the PCB pad area under the tab sets the effective RthJA. Mounting is surface mount, compatible with standard reflow profiles.
ROHS3 compliant, no exemption issues for EU or UKCA markets.