Patent ID: 7924539
Filing Date: 2011-04-12
Classification: H01L

Abstract:
1. A semiconductor integrated circuit having a protection circuit for protection against a fluctuation in high voltage between a power source line and a ground line, wherein the protection circuit has a first resistor and a capacitor connected in series between the power source line and the ground line, and a first logic circuit and a first transistor and a second resistor, wherein an input terminal of the first logic circuit is coupled between the first resistor and the capacitor, wherein an output terminal of the first logic circuit is coupled to a control terminal of the first transistor, wherein a first terminal of the first transistor is coupled to the power source line, wherein a second terminal of the first transistor is coupled to the ground line, wherein the control terminal of the first transistor is coupled to the ground line via the second resistor, wherein the first transistor is comprised of a first conduction type well region, a plurality of second conduction type diffusion layers in the well region, and a first conduction type diffusion layer in the well region, and wherein the control terminal is coupled to the first conduction type diffusion layer.