Patent ID: 7755870
Filing Date: 2010-07-13
Classification: H01L

Abstract:
1. A semiconductor integrated circuit device comprising: a circuit to be protected connected between a power supply line and a ground line; a first resistance connected to an external input terminal at one terminal and to an input terminal of the circuit to be protected at the other terminal; a first electrostatic discharge protection circuit including a first voltage drop circuit connected to the power supply line at one terminal and to the other terminal of the first resistance at the other terminal; a second electrostatic discharge protection circuit including a second voltage drop circuit connected to the other terminal of the first resistance at one terminal and to the ground line at the other terminal; the third electrostatic discharge protection circuit connected to the power supply line at one terminal and to the one terminal of the first resistance at the other terminal; and a fourth electrostatic discharge protection circuit connected to the one terminal of the first resistance at one terminal and to the around line at the other terminal, wherein the other terminal of the first electrostatic, discharge protection circuit and the one terminal of the second electrostatic discharge protection circuit are connected to the external input terminal through the first resistance, and the first electrostatic discharge protection circuit includes, as the first voltage drop circuit, at least one first serially-connected diode connected to the power supply line at an anode and to the other terminal of the first resistance at a cathode.