Schottky rectifier for low-voltage rails
The Microchip Technology 1N5819-1 is a 45 V, 1 A Schottky barrier rectifier in a through-hole DO-204AL (DO-41) axial package. Its 340 mV forward voltage drop at 1 A is the key selection parameter — that low Vf cuts conduction loss in rectification and freewheeling circuits where every millivolt of drop eats into the output rail margin. The 70 pF junction capacitance at 5 V and fast recovery (≤ 500 ns above 200 mA) mean it handles switching frequencies well beyond 50/60 Hz line rectification — suitable for DC-DC converter output rectification and flyback snubber clamping where the Schottky's lack of stored charge avoids reverse-recovery losses.
Thermal and leakage profile
Reverse leakage is 50 µA at the 45 V rated reverse voltage — this leakage doubles with temperature, so at 100 °C junction the standing loss through the diode in a reverse-biased OR-ing application needs to be budgeted. The DO-204AL (DO-41) axial-lead package is a standard through-hole footprint — it inserts into 0.040-inch diameter plated-through holes on a 0.100-inch pitch. The copper lead frame conducts heat to the PCB traces; for 1 A continuous duty, a 1-inch trace on each anode and cathode pad keeps the junction rise within the 125 °C limit.