Rectifier diode A semiconductor device used to convert alternating current into direct current. Usually it consists of a PN junction with anode and cathode terminals. Its structure is shown in Figure 1. The carriers in the P region are holes, and the carriers in the N region are electrons, which form a certain barrier in the P region and N interval. When a voltage is applied that makes the P region positive relative to the N region, the barrier is reduced, and storage carriers are generated near both sides of the barrier, which can pass through high current and has a low voltage drop (typical value is 0.7V), which is called the positive conduction state. If the opposite voltage is added to increase the barrier, it can withstand a high reverse voltage and flow a small reverse current (called reverse leakage current), which is called the reverse block state. The rectifier diode has obvious unidirectional conductivity. Rectifier diodes can be made of semiconducting materials such as germanium or silicon. Silicon rectifier diode has high breakdown voltage, low reverse leakage current and good high temperature performance. Usually high-voltage and high-power rectifier diodes are made of high-purity monocrystalline silicon (more doping is easy to reverse breakdown). The junction area of this device is large, and it can pass a large current (up to thousands of amPs), but the operating frequency is not high, generally below tens of KHZ. Rectifier diode is mainly used in a variety of low-frequency half-wave rectifier circuit, if you need to achieve full wave rectifier need to be connected to the rectifier bridge. Select and use
The 1N4001 rectifier diode is generally a flat silicon diode used in various power supply rectifier circuits.
When choosing a rectifier diode, the parameters such as maximum rectifier current, maximum reverse working current, cut-off frequency and reverse recovery time should be considered.
The rectifier diode used in the ordinary series regulated power supply circuit has no high requirement for the reverse recovery time of the cutoff frequency, as long as the rectifier diode with the maximum rectifier current and the maximum reverse working current meet the requirements is selected according to the requirements of the circuit. For example, 1N series, 2CZ series, RLR series and so on.
The rectifier diode used in the rectifier circuit and pulse rectifier circuit of the switching voltage regulator power supply should choose a rectifier diode with higher operating frequency and shorter reverse recovery time (such as RU series, EU series, V series, 1SR series, etc.) or choose a fast recovery diode. There is also a Schottky rectifier diode.
peculiarity
The rectifier diode uses the unidirectional conduction characteristic of PN junction to change alternating current into pulsating direct current. Rectifier diode current is large, most of the use of surface contact material packaging diodes. The shape of the rectifier diode is shown in Figure 1. In addition, the parameters of the rectifier diode in addition to the several introduced earlier, there is also the maximum rectifier current, which refers to the maximum current value allowed by the rectifier diode for a long time. It is the main parameter of the rectifier diode and the main basis for selecting the rectifier diode.
