| 摘要 |
An electrostatic discharge protection device including a PNP transistor, a protection circuit and an adjustment circuit is provided. An emitter of the PNP transistor is electrically connected to a pad, and a collector of the PNP transistor is electrically connected to a ground. The protection circuit is electrically connected between a base of the PNP transistor and the ground, and provides a discharge path. When an electrostatic signal occurs on the pad, the electrostatic signal is conducted to the ground through the discharge path and the PNP transistor. The adjustment circuit is electrically connected between the emitter and the base of the PNP transistor. When a power voltage is supplied to the pad, the adjustment circuit provides a control voltage to the base of the PNP transistor according to the power voltage, so as to prevent the emitter and the base of the PNP transistor from being forward biased. |
| 主权项 |
1. An electrostatic discharge protection device, comprising:
a PNP transistor, having an emitter electrically connected to a pad, and a collector electrically connected to a ground; a protection circuit, electrically connected between a base of the PNP transistor and the ground, and providing a discharge path, wherein when an electrostatic signal occurs on the pad, the electrostatic signal is conducted to the ground through the discharge path and the PNP transistor; and an adjustment circuit, electrically connected between the emitter and the base of the PNP transistor, wherein the adjustment circuit comprises: a switch, electrically connected between the emitter and the base of the PNP transistor; and a control unit, turning on the switch according to the power voltage, and turning off the switch according to the electrostatic signal, wherein the control unit comprises: a Zener diode, having a cathode electrically connected to the emitter of the PNP transistor; and a first resistor, having a first end electrically connected to an anode of the Zener diode, and a second end electrically connected to the ground, when a power voltage is supplied to the pad, the adjustment circuit provides a control voltage to the base of the PNP transistor according to the power voltage, so as to prevent the emitter and the base of the PNP transistor from being forward biased. |
