The MBRB1045-E3/81: The MBRB1045-/81: The Vishay MBRB1045-/81 is a 45 V, 10 A Schottky rectifier in a TO-263AB (D²PAK) surface-mount package. It is built for low forward voltage drop — 840 mV maximum at 20 A — which keeps conduction losses down in high-current rectification, OR-ing, and freewheeling applications. The 45 V reverse voltage rating gives headroom for 24 V and 28 V rails, but in a 48 V bus you are at the edge — derate accordingly. The 10 A average rectified current is the continuous rating; the 20 A test point for Vf shows the diode can handle repetitive peaks if the thermal path is solid.
Reverse leakage and junction temperature — the hidden thermal load
Reverse leakage is 100 µA at 45 V. At the 150 °C junction limit leakage climbs significantly. The junction temperature range spans -65°C to 150°C, which covers industrial and most automotive under-hood environments. The wide cold-end margin is typical for Schottky diodes and matters for cold-start surge conditions.
Package and rework — the D²PAK reality
TO-263AB (D²PAK) is a surface-mount package with a large exposed tab on the bottom. The tab is the cathode and the primary thermal path. Rework is straightforward with hot air: preheat the board to 125 °C, hit the tab with a focused nozzle at 300 °C, and lift the part when the solder on all three terminals flows. The tab takes the most heat — starve it and the part stays stuck.