Patent ID: 6025746
Filing Date: 2000-02-15
Classification: H01L

Abstract:
In a MOS integrated circuit semiconductor device having electrostatic protection circuits protecting active and passive components in the device from electrostatic discharge on an external power supply voltage line, and wherein said device includes an internal power supply voltage line whose voltage is derived from the external power supply voltage line, additional protection circuitry in the device for protecting the active and passive components from electrostatic discharge between an external power supply line and an internal power supply line, said additional protection circuitry comprising:bi-directional diodes between said internal and external voltage lines for shunting electrostatic charges between said internal voltage line to said external voltage line;and a pair of MOS transistors, one transistor connected between said internal voltage line and a ground line and the other transistor connected between the ground line and said external voltage line, the gate of each transistor connected to one of the ground line or to the transistor's connected voltage line depending upon whether the transistor is p-type or n-type, said transistors shunting an electrostatic charge between the ground line and one or the other of the voltage lines.