Working Principle and Application Places of Rectifier Diodes

Rectifier diodes are semiconductor devices that utilize the unidirectional conductivity of PN junctions to convert alternating current into pulsating direct current.

Depending on the material type and manufacturing process, they can be categorized into standard rectifier diodes, fast recovery rectifier diodes, ultrafast recovery rectifier diodes, Schottky diodes, and power diodes, among others.

The working principle of rectifier diodes is as follows: Under forward bias, due to the high concentration of doping, electrons move toward the P-region and holes move toward the N-region. When they meet at the PN junction, electrons are captured by holes, generating a small amount of heat. This narrows the depletion region of the PN junction, allowing current to flow. Under reverse bias, electrons and holes do not meet at the PN junction, resulting in minimal reverse current in rectifier diodes.

Standard rectifier diodes have the advantage of strong reverse voltage tolerance but relatively slow switching speeds. Fast recovery rectifier diodes offer faster switching speeds and higher reverse voltage tolerance. Ultrafast recovery rectifier diodes have even shorter recovery times and better high-frequency characteristics compared to fast recovery diodes. Schottky diodes feature lower forward voltage drops and faster switching speeds, while power diodes are suitable for high-voltage and high-current applications.

When selecting rectifier diodes, key parameters to consider include maximum rectified current, maximum reverse working current, cutoff frequency, and reverse recovery time.

In summary, different rectifier diodes are used for different applications. Choosing the appropriate rectifier diode based on specific requirements ensures circuit stability and reliability.