Overview of rectifier diodes

Lead: rectifier diode A semiconductor device used to convert alternating current into direct current. The most important feature of a diode is unidirectional conductivity. In the circuit, current can only flow in from the anode of the diode, and the cathode flows out. Usually it contains a PN junction, with both positive and negative terminals. Its structure is shown in the figure. The carrier in the P region is a hole, the carrier in the N region is an electron, and a certain barrier is formed in the P region and the N region. When a voltage is applied to make the P region a positive voltage with respect to the N region, the potential barrier is lowered, storage carriers are generated near both sides of the barrier, and a large current can be passed through, and a low voltage drop (typically 0.7 V) is obtained. The wizard is in an open state. If the opposite voltage is applied, the bit-barrier increases, the high reverse voltage can be tolerated, and a small reverse current flows (called reverse leakage current), which is called the reverse blocking state. The rectifier diode has a significant one-way conductivity. The rectifier diode can be made of materials such as semiconductor germanium or silicon. Silicon rectifier diodes have high breakdown voltage, low reverse leakage current, and good high temperature performance. Usually high-voltage high-power rectifier diodes are made of high-purity single crystal silicon (reverse breakdown is easy when doping more). This device has a large junction area and can pass a large current (up to thousands of amps), but the operating frequency is not high, generally below tens kHz. Rectifier diodes are mainly used for various low-frequency half-wave rectifier circuits. If full-wave rectification is required, they must be used as rectifier bridges.

Rectifier diodes are generally planar silicon diodes used in various power rectifier circuits. When using rectifier diodes, the parameters such as maximum rectified current, maximum reverse operating current, cutoff frequency, and reverse recovery time should be considered.

The rectifying diode used in a common series-regulating power supply circuit has a low requirement for the reverse recovery time of the cut-off frequency, so long as the rectifying diode whose maximum rectified current and maximum reverse operating current meet the requirements can be selected according to the requirements of the circuit. For example, 1N series, 2CZ series, RLR series, etc.

The rectifying circuit for switching power supply and the rectifying diode used in the pulse rectifying circuit should use a rectifier diode with high operating frequency and short reverse recovery time (such as RU series, EU series, V series, 1SR series, etc.) or Fast recovery diodes. There is also a Schottky rectifier diode.

The rectifying diode uses the unidirectional conductive characteristic of the PN junction to convert the alternating current into pulsed direct current. Rectifier diodes have large leakage currents, and most are diode-packaged diodes. In addition, the parameters of the rectifier diode, in addition to the several introduced above, also have the maximum rectified current, which refers to the maximum current value that the rectifying diode allows to pass for a long time. It is the main parameter of the rectifier diode, and is the main basis of the rectifier diode for the option.

Source: Chongqing Electronic Technology Co., Ltd.