Package and board integration — TO-263-3 (D²Pak)
The RB218NS-40TL comes in a TO-263-3 (D²Pak) surface-mount package with a large exposed copper tab on the bottom.
Headline ratings — 40 V reverse, 20 A per diode
This is a dual Schottky rectifier in a common-cathode configuration, rated 40 V DC reverse maximum and 20 A average rectified current per diode. The common-cathode pair is wired for OR-ing or center-tapped full-wave rectification — the two anodes are independent, so each half of the pair handles its own rail or winding phase. Forward voltage is 770 mV maximum at 10 A per diode — that is the conduction loss at half the rated current. Reverse leakage is 5 µA at 40 V, which the manufacturer flags as 'SUPER LOW IR' — a meaningful advantage in battery-powered or standby circuits where leakage current drains the rail when the diode is blocking.
Switching speed and thermal limits
Classified as fast recovery (<= 500 ns, > 200 mA Io), though as a Schottky the switching speed is inherently limited by junction capacitance rather than stored charge — the recovery classification confirms it is suitable for switching frequencies in the tens to low hundreds of kHz without significant reverse-recovery losses. The TO-263-3 tab must be soldered to a sufficient copper area — a typical two-ounce copper pour of at least 600 mm² keeps the junction rise within safe margin at 20 A continuous per diode.