Schottky rectifier for low-power rail protection
The Vishay BAT165-G3/H is a Schottky barrier rectifier rated for 40 V reverse voltage and 500 mA average rectified current. It targets low-voltage rail protection, polarity protection, and freewheeling diode roles in DC-DC converters and portable equipment where forward drop matters more than breakdown margin.
Forward drop and leakage — the efficiency pair
Forward voltage is specified at 540 mV maximum at 250 mA forward current. That is the conduction loss floor for the typical load point — a designer sizing for 500 mA peak sees roughly 270 mW dissipation at full load before derating for ambient temperature. Reverse leakage is 8 µA at 40 V reverse bias. In a battery-powered circuit drawing microamps in sleep, that leakage current can dominate the off-state budget. The 150°C junction temperature rating gives headroom for reflow and moderate self-heating, but leakage rises exponentially with temperature — expect higher standby draw at elevated ambient.
Switching speed and package fit
Recovery time is listed as fast recovery ≤ 500 ns at > 200 mA forward current. That is adequate for line-frequency rectification and low-frequency switching up to tens of kilohertz, but not for high-speed synchronous rectification in a 500 kHz+ converter — a faster Schottky with lower junction capacitance would be needed there. The DO-219AC (microSMF) package is a small surface-mount SOD-123FL-like outline. It fits reflow assembly with standard pick-and-place and requires no thermal pad — the junction-to-ambient thermal resistance is set by the copper pad area on the PCB. The 8.4 pF capacitance at 10 V is low enough to avoid signal degradation in protection clamping roles.
Active production — no LTB concern
Product status is listed as Active.