| 摘要 |
The overvoltage protection circuit (12) is connected across the supply terminals of an integrated circuit (10). The protection circuit has a bipolar transistor connected to the first and second supply terminals (V+,V-) by its collector and emitter respectively. A capacitor is connected on one side to the positive supply and on the other side to the base of an emitter follower circuit formed by two transistors. A current source connects the capacitor to the negative supply line. The protection circuit provides a variable resistance path across the supply to divert overvoltage currents and limit voltage rise. A supplementary terminal (P) is connected to the integrated circuit and has blocking diodes (D1,D2) connecting it to the supply lines. |
