Abstract: The invention provides a semiconductor device including an ESD protection circuit with a high ESD protection characteristic. An RC timer included discharge portion including an RC timer formed by a resistor element and a capacitor element and a PLDMOS transistor is formed so as to turn on only when a surge voltage due to static electricity is applied. Furthermore, a noise prevention portion including first and second NMOS off transistors of which the source electrode and the drain electrode are connected is formed. The source electrode of the PLDMOS transistor of the RC timer included discharge portion is connected to a power supply line. The drain electrode of the PLDMOS transistor and the drain electrode of the first NMOS off transistor are connected. The source electrode of the second NMOS off transistor is connected to a ground line.

Abstract: A semiconductor apparatus includes: first and second power-supply terminals; an internal circuit connected between the first and second power-supply terminals; and a protection circuit connected in parallel with the internal circuit between the first and second power-supply terminals, the protection circuit including: a series circuit that includes a resistor and a first capacitor, and is connected in parallel with the internal circuit between the first and second power-supply terminals; a first MOS transistor that is connected in parallel with the series circuit, and is controlled according to a voltage at a connection point between the resistor and the first capacitor; and a switch circuit that is connected in parallel with the resistor, is turned on in a delayed manner after a power-supply voltage is applied between the first and second power-supply terminals, and changes the voltage at the connection point so that the first MOS transistor is turned off.

Abstract: A semiconductor apparatus includes: first and second power-supply terminals; an internal circuit connected between the first and second power-supply terminals; and a protection circuit connected in parallel with the internal circuit between the first and second power-supply terminals, the protection circuit including: a series circuit that includes a resistor and a first capacitor, and is connected in parallel with the internal circuit between the first and second power-supply terminals; a first MOS transistor that is connected in parallel with the series circuit, and is controlled according to a voltage at a connection point between the resistor and the first capacitor; and a switch circuit that is connected in parallel with the resistor, is turned on in a delayed manner after a power-supply voltage is applied between the first and second power-supply terminals, and changes the voltage at the connection point so that the first MOS transistor is turned off.

Abstract: A transistor structure that improves an ESD withstand voltage is offered. There is formed a P-type insulating isolation layer that divides an N-type epitaxial layer into a plurality of regions and isolates neighboring regions from each other. A diffusion layer doped with high concentration N-type impurities and an electrode extraction layer are formed in a surface of the epitaxial layer between a low impurity concentration drain layer and the insulating isolation layer. The diffusion layer and the electrode extraction layer are connected with a drain electrode. When an excessive positive surge voltage is applied to a source electrode, a parasitic diode that makes a current path including the diffusion layer and the electrode extraction layer is turned on to shunt an ESD current from the source electrode to the drain electrode, in addition to other parasitic diodes included in a conventional structure.

Abstract: The invention provides a semiconductor device including an ESD protection circuit with a high ESD protection characteristic. An RC timer included discharge portion including an RC timer formed by a resistor element and a capacitor element and a PLDMOS transistor is formed so as to turn on only when a surge voltage due to static electricity is applied. Furthermore, a noise prevention portion including first and second NMOS off transistors of which the source electrode and the drain electrode are connected is formed. The source electrode of the PLDMOS transistor of the RC timer included discharge portion is connected to a power supply line. The drain electrode of the PLDMOS transistor and the drain electrode of the first NMOS off transistor are connected. The source electrode of the second NMOS off transistor is connected to a ground line.

Abstract: A semiconductor apparatus includes: first and second power-supply terminals; an internal circuit connected between the first and second power-supply terminals; and a protection circuit connected in parallel with the internal circuit between the first and second power-supply terminals, the protection circuit including: a series circuit that includes a resistor and a first capacitor, and is connected in parallel with the internal circuit between the first and second power-supply terminals; a first MOS transistor that is connected in parallel with the series circuit, and is controlled according to a voltage at a connection point between the resistor and the first capacitor; and a switch circuit that is connected in parallel with the resistor, is turned on in a delayed manner after a power-supply voltage is applied between the first and second power-supply terminals, and changes the voltage at the connection point so that the first MOS transistor is turned off.

Abstract: A patterning area of an output circuit is reduced while securing strong enough ESD tolerance. In the output circuit of this invention, an output of a first amplifier and an output of a second amplifier are connected to a common output pad. Each of the amplifiers is driven by each of signals ?1 and ?2 from an internal circuit, respectively. The first amplifier has larger driving capacity than the second amplifier. A high voltage side power supply terminal of the second amplifier is provided with a power supply voltage VDD from a power supply pad through a first protection resistor, while a low voltage side power supply terminal of the second amplifier is provided with a ground voltage VSS from a ground pad through a second protection resistor. And a third protection resistor is connected between an output of the second amplifier and an output terminal. The first, second and third protection resistors are made of metal wirings, and their resistance is preferably about 10?.

Abstract: A transistor structure that improves an ESD withstand voltage is offered. There is formed a P-type insulating isolation layer that divides an N-type epitaxial layer into a plurality of regions and isolates neighboring regions from each other. A diffusion layer doped with high concentration N-type impurities and an electrode extraction layer are formed in a surface of the epitaxial layer between a low impurity concentration drain layer and the insulating isolation layer. The diffusion layer and the electrode extraction layer are connected with a drain electrode. When an excessive positive surge voltage is applied to a source electrode, a parasitic diode that makes a current path including the diffusion layer and the electrode extraction layer is turned on to shunt an ESD current from the source electrode to the drain electrode, in addition to other parasitic diodes included in a conventional structure.

Abstract: A patterning area of an output circuit is reduced while securing strong enough ESD tolerance. In the output circuit of this invention, an output of a first amplifier and an output of a second amplifier are connected to a common output pad. Each of the amplifiers is driven by each of signals ?1 and ?2 from an internal circuit, respectively. The first amplifier has larger driving capacity than the second amplifier. A high voltage side power supply terminal of the second amplifier is provided with a power supply voltage VDD from a power supply pad through a first protection resistor, while a low voltage side power supply terminal of the second amplifier is provided with a ground voltage VSS from a ground pad through a second protection resistor. And a third protection resistor is connected between an output of the second amplifier and an output terminal. The first, second and third protection resistors are made of metal wirings, and their resistance is preferably about 10?.