Main parameters, selection, and application of diode rectifier devices — SUNMATE

Main parameters, selection, and application of diode rectifier devices

Diodes are widely used in electronic circuits. How to select based on parameters and what conditions should be met for selection?

1. Main parameters of rectification:

VRRM: Maximum repetitive peak reverse current (reverse breakdown voltage)

I (AV): Maximum forward average current

VF: Maximum forward voltage (maximum voltage at both ends of the diode during conduction)

IR: Maximum reverse current (leakage current)

Trr: Maximum reverse recovery time

IFSM: Forward peak surge current

2. Selection and Calculation of Rectifier Bridges in General Rectifier Circuits

VRRM ≥ (1.25 √ 2umax+(1.25 √ 2umax) 20%) (umax maximum input voltage)

Assuming the input AC voltage is 265V, calculate the above

VRRM=1.25 * 1.414 * 265=468+0.2 * 468=562V, actual selection 600V

I (AV) ≥ PO/ η UiminCOS φ (PO maximum output power, η Efficiency=I0V0/Ii? Vi? 100%, uimin minimum input voltage.

COS φ= P/S=P/√ P2+Q2 (P: active power, S: apparent power, Q: reactive power, general power factor 0.5-0.7)

Assuming an output power of 100W, an efficiency of 88%, and a minimum input voltage of 85V, the calculation shows:

I (AV) ≥ 100/0.88? 85? 0.6=2.23A, usually 4A is selected, but in practice, there is a large margin based on factors such as circuit structure, heat dissipation space, and usage situation. For 100W power supply, the actual selection is mostly 6-8A current.