Diode Reverse Recovery Calculator

Reverse recovery was first explained in 1952 by Hall and Shockley at Bell Labs using the minority-carrier storage model: when a P-N diode turns off, the stored minority carriers (holes on the N side, electrons on the P side) must be swept out or recombine before the junction can support reverse voltage. During this brief interval the diode conducts backward — creating a "recovery tail" whose area is the total recovery charge Qrr.

Schottky diodes (Walter Schottky, 1938 theoretical, Kirk & Wayne, 1968 practical) eliminate reverse recovery almost entirely by using a metal-semiconductor junction — no minority carriers to store, so Qrr is dominated by parasitic junction capacitance rather than carrier extraction. The trade-off: Schottky breakdown voltage is limited to ~200 V and leakage current is much higher than silicon P-N.

The 2010s brought SiC and GaN wide-bandgap devices: SiC Schottky diodes work at 600-1700 V with near-zero Qrr, and GaN transistors have intrinsic body-diode recovery below 50 nC. This enabled switching frequencies to move from 100 kHz (silicon) to 500 kHz-5 MHz (WBG), shrinking power-converter magnetics by 3-5×. Modern server PSUs, EV onboard chargers, and PV inverters are dominated by SiC Schottkies and GaN HEMTs for exactly this recovery-loss advantage.

Enter reverse recovery time trr, peak reverse current Irrm, blocking voltage VR, and switching frequency. The tool computes triangular recovery charge Qrr ≈ ½·trr·Irrm, energy per recovery event E = Qrr·VR, and switching power loss P = E·f. Snap-off (abrupt) recovery produces sharp di/dt that radiates EMI; soft-recovery diodes trade slightly longer trr for much gentler di/dt.

Rule of thumb: at 100 kHz switching, a silicon fast-recovery diode (trr ≈ 50 ns) can easily dissipate more recovery loss than forward-drop loss. This is why Schottky is preferred below 100 V and why SiC is dominant above 600 V for any f > 50 kHz. Everything runs client-side; no values leave your browser.