| 摘要 |
Electrostatic discharge protection for analog switches using silicon-controlled rectifiers. Two silicon-controlled rectifiers (SCRs) may be formed in a common isolation region of an integrated circuit. Each SCR has its gate and cathode coupled together so as to be self triggering. The SCRs are connected in parallel in reverse polarity and coupled between the analog switch input or output and ground. In normal switch operation, both SCRs will be off, though when the voltage of the protected switch connection exceed one of the supply rails, one of the SCRs will trigger, providing a low impedance connection to ground. Once the voltage returns to normal, the SCR will automatically release.
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