汉英对照:
Chinese-English Translation:
钳位电压是指限制电压。这个限制的对象，可以是需要过压保护的对象，譬如开关电源中的MOS管，需要一个钳位网络来限制D、S极间电压，保护MOS不被损坏。
Clamp voltage is the limiting voltage. The object of this restriction can be the object that needs over-voltage protection, such as MOS transistor in switching power supply. A clamping network is needed to limit the voltage between D and S poles to protect MOS from damage.
钳位电压是指限制电压。这个限制的对象，可以是需要过压保护的对象，譬如开关电源中的 MOS 管，需要一个钳位网络来限制 D、S 极间电压，保护 MOS 不被损坏。
Clamp voltage is the limiting voltage. The object of this restriction can be the object that needs over-voltage protection, such as MOS transistor in switching power supply. A clamping network is needed to limit the voltage between D and S poles to protect MOS from damage.
电压钳位器件
Voltage clamp
它可以构成电压调节器或瞬态抑制器，可以用来限制电路两端的电压。电压钳位器件都是典型的半导体，如齐纳二极管、暂态电压抑制器、压敏电阻 (VDR)等。 齐纳二极管在正向导通时跟普通二极管一样，但是当它的反向电压高到一定程度时，会因击穿而导通。耐压小于 6V 的低压齐纳二极管的伏安特性曲线斜率较小，是逐渐导通的。高压齐纳二极管 (雪崩击穿二极管)耐压大于 6V，它的伏安特性曲线斜率大，故导通迅速。齐纳二极管击穿时会产生一些噪声，我们通常在它两端并联一个小电容来消除噪声。
It can be used to limit the voltage at both ends of the circuit. Voltage clamp devices are typical semiconductors, such as zener diode, transient voltage suppressor, varistor (VDR). Zener diode is the same as ordinary diode in forward conduction, but when its reverse voltage is high to a certain extent, it will turn on due to breakdown. The slope of volt ampere characteristic curve of low voltage zener diode with voltage withstand less than 6V is small, and it is gradually on. The voltage withstand voltage of high voltage zener diode (avalanche breakdown diode) is greater than 6V, and its volt ampere characteristic curve slope is large, so it can conduct quickly. Zener diode will produce some noise when it breaks down. We usually connect a small capacitor at its two ends to eliminate the noise.
暂态电压抑制器和齐纳二极管相似，但它更适用于峰值电流很高的应用场合。暂态电压可以是单向或双向的，额定电压从 5V 到几百伏不等。应用于 275V 交流场合的暂态电压抑制器，即使在瞬时电流很高的情况下，也可以使其峰值浪涌电压低于 600V。
Transient voltage suppressors are similar to zener diodes, but are more suitable for applications with high peak currents. Transient voltages can be unidirectional or bidirectional, with rated voltages ranging from 5V to several hundred volts. The transient voltage suppressor applied in 275v AC can make the peak surge voltage lower than 600V even in the case of high instantaneous current.
VDR 在低压时电阻很高，高压时电阻很低。所以两端电压增加时，它会逐渐导通。VDR 可以吸收很高的浪涌能量，这种器件一般以焦耳而不是瓦特来定额，因为浪涌能量一般是瞬间的。在瞬时电流很高的情况下，交流额定电压为 275V 的 VDR 将会击穿，可以将电压限制在 710V 左右。
VDR has high resistance at low voltage and low resistance at high voltage. So when the voltage at both ends increases, it will gradually turn on. VDR can absorb very high surge energy, which is usually rated in joules rather than watts, because the surge energy is usually instantaneous. When the instantaneous current is very high, the VDR with AC rated voltage of 275v will break down and the voltage can be limited to about 710v.
