Electrostatic discharge protection circuit device

An electrostatic discharge protection circuit device comprising:

• a first electrostatic discharge protection circuit connected between a first external terminal supplied with a first power supply voltage at time of ordinary operation and a first ground terminal;
• a plurality of second electrostatic discharge protection circuits each connected between a corresponding second external terminal supplied with a corresponding second power supply voltage at the time of the ordinary operation and a corresponding second ground terminal, each of the second electrostatic discharge protection circuits having substantially the same configuration as that of the first electrostatic discharge protection circuit;
• a trigger signal line which connects in common an output node of a surge detection circuit of the first electrostatic discharge protection circuit and output nodes of surge detection circuits of the second electrostatic discharge protection circuits, and transfers a surge detection output of the first electrostatic discharge protection circuit and a surge detection output of one of the second electrostatic discharge protection circuits to the other electrostatic discharge protection circuits as a trigger signal;
• and
• a common discharge line connected directly to the first ground terminal, connected to the second ground terminals via a parallel circuit composed of a forward-connected parasitic diode element and a reverse-connected parasitic diode element, and used commonly by the first electrostatic discharge protection circuit and the second of electrostatic discharge protection circuits.