Patent ID: 7307822

Claim:
A semiconductor integrated circuit apparatus comprising: a plurality of power supply system circuits, in which power supply terminals or ground terminals, or the power supply terminals and the ground terminals, are separated from each other between the power supply system circuits; an electrostatic discharge protecting circuit connected between a power supply terminal and a ground terminal of each of the power supply system circuits; an internal circuit provided in each of the power supply system circuits; an internal signal transmitting line which transmits a signal from an internal circuit of a first power supply system circuit of the power supply system circuits to an internal circuit of a second power supply system circuit of the power supply system circuits; a surge input detecting circuit which detects a surge input to at least one of the power supply terminals; and an input protecting circuit which is provided at an input side of the internal circuit of the first power supply system circuit, in which the input protecting circuit and the output logic setting circuit are controlled in response to an output of the surge input detecting circuit so that, when the surge input detecting circuit detects a surge input, the input protecting circuit limits a voltage to be applied to an element in the input protecting circuit and the output logic setting circuit limits a voltage of a signal transmitted from the internal signal transmitting line, and an output logic setting circuit which is provided at an output side of the intemal circuit and which sets a logic level of a signal outputted to the internal signal transmitting line to a predetermined level.