US 6,605,963 B2 · Semiconductor integrated circuit and method of switching source potential of transistor in semiconductor integrated circuit

Abstract

A semiconductor integrated circuit, comprising a circuit unit having a predetermined function such as a level shifter circuit or a driver transistor circuit by a combination of a plurality of transistors, is disclosed. Among a plurality of the transistors of the circuit unit, the source potential of at least one transistor adapted to turn off during the standby period of the circuit unit is changed. Preferably, the semiconductor integrated circuit is configured to reduce the sub-threshold current flowing between the source and the drain of at least one transistor adapted to turn off during the standby period of the circuit unit by changing the source potential at a timing based on the standby period of the circuit unit in such a manner that a predetermined bias voltage is applied between the gate and the source of the transistor. A method of switching the source potential of at least one transistor in the semiconductor integrated circuit having the configuration described above is also disclosed.

Claims42

Dependent claims

A semiconductor integrated circuit comprising a circuit unit having a predetermined function formed of a plurality of transistors,

wherein the source potential of at least one of a plurality of transistors which turns off during the standby period of said circuit unit is changed in a manner such that a negative bias voltage is applied between the gate and the source of said transistor, and
wherein the source potential of at least one of a plurality of transistors which turns on during the standby period is not changed substantially.

A semiconductor integrated circuit comprising a circuit unit having a predetermined function formed of a plurality of transistors,

wherein the source potential of at least one of a plurality of transistors which turns off during the standby period of said circuit unit is changed in a manner such that a minus bias voltage is applied between the gate and the source of said transistor,
wherein said circuit unit is a level shifter circuit including a plurality of transistors for changing the potential of an input signal upward or downward,
wherein said level shifter circuit includes at least a transistor of a first conduction type and at least a transistor of a second conduction type for changing the potential of said input signal, a switching element for changing the source potential of said transistor of a first conduction type is assigned to one or a plurality of transistors of a first conduction type adapted to turn off during the standby period of said level shifter circuit, said switching element includes a transistor of a second conduction type having a drain connected to the source of said transistor of a first conduction type, the source of said transistor of a second conduction type is connected to a power supply for applying a predetermined bias voltage between the gate and the source of said transistor of a first conduction type, a signal for turning on said transistor of a second conduction type during the standby period of said level shifter circuit is supplied to the gate of said transistor of a second conduction type, and the source potential of said transistor of a first conduction type is kept substantially at a potential equal to the power supply during the standby period of said level shifter circuit, and
wherein the source potential of at least one of a plurality of transistors which turns on during the standby period is not changed substantially.

1 more element

A semiconductor integrated circuit comprising a circuit unit having a predetermined function formed of a plurality of transistors,

wherein the source potential of at least one of a plurality of transistors which turns off during the standby period of said circuit unit is changed in a manner such that a minus bias voltage is applied between the gate and the source of said transistor,
wherein said circuit unit is a level shifter circuit including a plurality of transistors for changing the potential of an input signal upward or downward,
wherein said level shifter circuit includes at least a transistor of a first conduction type and at least a transistor of a second conduction type for changing the potential of said input signal, a switching element for changing the source potential of one or a plurality of transistors of a first conduction type adapted to turn off during the standby period of said level shifter circuit is assigned to said transistor of a second conduction type, said switching element includes a transistor of a first conduction type having a drain connected to the source of said transistor of a second conduction type, the source of said transistor of a first conduction type is connected to a power supply for applying a predetermined bias voltage between the gate and the source of said transistor of a first conduction type, a signal for turning on said transistor of a first conduction type during the standby period of said level shifter circuit is supplied to the gate of said transistor of a first conduction type, and the source potential of said transistor of a second conduction type is kept substantially at a potential equal to the power supply during the standby period of said level shifter circuit, and
wherein the source potential of at least one of a plurality of transistors which turns on during the standby period is not changed substantially.

1 more element

A semiconductor integrated circuit comprising a level shifter circuit in which the gates and the drains of a first P-ch transistor and a second P-ch transistor for converting the potential of an input signal from the potential of a first power supply to the potential of a second power supply are interconnected by cross coupling, and the gate of at least selected one of said first and second P-ch transistors is connected to the drain of a first N-ch transistor,

wherein the source of said first N-ch transistor of said level shifter circuit is connected to said first power supply through the drain of a third P-ch transistor on the one hand and connected to a third power supply lower than the potential of said first and second power supplies through the drain of a second N-ch transistor, said input signal is input to the gate of said first N-ch transistor.

A semiconductor integrated circuit comprising a level shifter circuit in which the gates and the drains of a first N-ch transistor and a second N-ch transistor for converting the potential of an input signal form the potential of a fourth power supply to the potential of a fifth power supply are interconnected by cross coupling, and the gate of at least a selected one of said first and second N-ch transistors is connected to the drain of a first P-ch transistor;

wherein the source of said first P-ch transistor of said level shifter circuit is connected to said fourth power supply through the drain of a third N-ch transistor on the one hand and connected to a sixth power supply higher than the potential of said fourth and fifth power supplies through the drain of a second P-ch transistor on the other hand.

Dependencies are inferred from the claim text.

Semiconductor integrated circuit and method of switching source potential of transistor in semiconductor integrated circuit

Life of this patent

Semiconductor integrated circuit and method of switching source potential of transistor in semiconductor integrated circuit

Life of this patent

Abstract

Claims42