PN结

PN结是由p型半导体（空穴过剩）与n型半导体（电子过剩）接触形成的。该结形成耗尽区，载流子复合，产生内建电位势垒。它具有整流特性，正向偏置时电流易通过，反向偏置时阻断电流。在TVS二极管等钳位器件中，PN结被设计为在特定电压阈值下通过雪崩击穿提供瞬态电压抑制。

PN结的工作原理基于载流子跨结扩散和耗尽区的形成。正向偏置时，外部电压降低内建电位，使多数载流子跨结流动。反向偏置时，势垒增加，阻止电流流动，直到达到击穿电压。在TVS二极管中，结被设计为在预定电压下发生受控雪崩击穿，将瞬态过压浪涌分流至地，保护下游元件。

The PN junction operates based on the diffusion of charge carriers across the junction and the formation of a depletion region. Under forward bias, the external voltage reduces the built-in potential, allowing majority carriers to flow across the junction. Under reverse bias, the potential barrier increases, preventing current flow until the breakdown voltage is reached. In TVS diodes, the junction is designed to undergo controlled avalanche breakdown at a predetermined voltage to shunt transient overvoltage surges to ground, protecting downstream components.