Abstract: There is provided a power switching circuit capable of completely breaking a current in an OFF state of a switch connecting power sources even when a voltage difference is generated between the power sources of a plurality of functional blocks separated from each other on an LSI chip. A gate control circuit 1a has a control signal terminal INCNT, a first power imputer terminal IG11, and a second power supply terminal IG12 as input terminals and has a first output terminal OG11 and a second output terminal OG12 as output terminals. The gate of a second P-type transistor P2 is connected to the first output terminal OG11 of the gate control circuit 1a and the gate of a second P-type transistor P2 is connected to the second output terminal OG12 of the gate control circuit 1a, wherein the first P-type transistor P1 and the second P-type transistor P2 are connected in series between a first power source VDD1 and a second power source VDD2 to form a switch section.

Abstract: In a semiconductor integrated circuit device, a plurality of electrode pads for external connection are arranged in a zigzag pattern. Some electrode pads of the electrode pads of the plurality of I/O cells which are closer to a side of the semiconductor chip, each have an end portion closer to the side of the semiconductor chip, the end portion being set at the same position as that of an end portion of the corresponding I/O cell. A power source-side protective circuit and a ground-side protective circuit against discharge of static electricity are provided with the power source-side protective circuit being closer to the scribe region. A distance between a center position of one of the electrode pads and the ground-side protective circuit of the corresponding I/O cell and a distance between a center position of the other one electrode pad and the ground-side protective circuit of the corresponding I/O cell are both short and are substantially equal between each I/O cell.

Abstract: An oscillation circuit according to the present invention comprises a solid-state oscillator, an amplifier for feedback-controlling the solid-state oscillator, and ESD protecting circuits respectively connected to the input and output sides of the amplifier, wherein the ESD protecting circuit on the input side of the amplifier comprises an ESD protecting element whose constituent is a diode having a P-type diffusion layer and an N-type diffusion layer, and the ESD protecting circuit on the output side of the amplifier comprises an ESD protecting element whose constituent is an MOS transistor.

Abstract: In a level shift circuit, the threshold voltage of N-type high-voltage transistors, to whose gates the voltage of a low-voltage supply VDD is applied, is set low. An input signal IN powered by the low-voltage supply VDD is input to the gate of an N-type transistor by way of an inverter. Therefore, even if the potentials at nodes W3 and W4 exceed the voltage of the low-voltage supply VDD, reverse current flow from the nodes W3 and W4 via parasitic diodes within the inverters into the low-voltage supply VDD is prevented. A protection circuit, composed of N-type transistor whose respective gates are fixed to the low-voltage supply VDD, is disposed between the two N-type high-voltage transistors N5, N6 and two N-type low-voltage transistors N1, N2 for receiving the complementary signals IN and XIN, thereby preventing the breakdown of those N-type complementary-signal-receiving transistors.

Abstract: There is provided a power switching circuit capable of completely breaking a current in an OFF state of a switch connecting power sources even when a voltage difference is generated between the power sources of a plurality of functional blocks separated from each other on an LSI chip. A gate control circuit 1a has a control signal terminal INCNT, a first power imputer terminal IG11, and a second power supply terminal IG12 as input terminals and has a first output terminal OG11 and a second output terminal OG12 as output terminals. The gate of a second P-type transistor P2 is connected to the first output terminal OG11 of the gate control circuit 1a and the gate of a second P-type transistor P2 is connected to the second output terminal OG12 of the gate control circuit 1a, wherein the first P-type transistor P1 and the second P-type transistor P2 are connected in series between a first power source VDD1 and a second power source VDD2 to form a switch section.

Abstract: In a level shift circuit, the threshold voltage of N-type high-voltage transistors, to whose gates the voltage of a low-voltage supply VDD is applied, is set low. An input signal IN powered by the low-voltage supply VDD is input to the gate of an N-type transistor by way of an inverter. Therefore, even if the potentials at nodes W3 and W4 exceed the voltage of the low-voltage supply VDD, reverse current flow from the nodes W3 and W4 via parasitic diodes within the inverters into the low-voltage supply VDD is prevented. A protection circuit, composed of N-type transistor whose respective gates are fixed to the low-voltage supply VDD, is disposed between the two N-type high-voltage transistors N5, N6 and two N-type low-voltage transistors N1, N2 for receiving the complementary signals IN and XIN, thereby preventing the breakdown of those N-type complementary-signal-receiving transistors.