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US 2003/0155962 A1Published application
Semiconductor device
AssigneeHitachi, Ltd.
InventorsKiyoo Itoh, Hiroyuki Mizuno
Life of this patent
Estimating the term…
Abstract
The well voltage of a CMOS circuit having low-threshold-voltage MOSFETs is controlled when the power supply is turned on, during normal operation, and when the supply voltage is cut off. The CMOS circuit can thus operate stably with lower power consumption, because latching-up is reduced when the supply voltage is applied to the CMOS circuit or when the supply voltage is cut off, and subthreshold current is decreased during normal operation.
Claims25
A semiconductor device, comprising:
- a CMOS circuit having a plurality of MOSFETs having respective threshold voltages less than or equal to 0.5 V;
- well voltage applying means for applying a well voltage to the well of each of the plurality of MOSFETs of the CMOS circuit;
- and
- supply voltage applying means for applying a supply voltage to the CMOS circuit;
- wherein the supply voltage applying means begins to apply the supply voltage after the well voltage applying means begins to apply the well voltage.
2 more elements
A semiconductor device, comprising:
- a CMOS circuit having a plurality of MOSFETs having respective threshold voltages less than or equal to 0.5 V;
- a voltage conversion circuit arranged to receive a first voltage as a supply voltage and to output a second voltage derived from said first voltage as a well voltage to the well of each of the plurality of MOSFETs of the CMOS circuit;
- and
- supply voltage applying means for applying a third voltage as a supply voltage to the CMOS circuit;
- wherein the supply voltage applying means begins to apply the third voltage to the CMOS circuit after the voltage conversion circuit receives the first voltage.
2 more elements
A semiconductor device, comprising:
- a circuit for fixing the well potential of a CMOS circuit having a plurality of MOSFETs having respective threshold voltages less than or equal to 0.5 V;
- and
- a circuit for varying the well potential of said plurality of MOSFETs by capacitive coupling according to the variation of an input signal of said CMOS circuit.
A semiconductor device, comprising:
- a dynamic memory cell having one MOSFET and a capacitor;
- and
- a CMOS circuit having a plurality of MOSFETs having respective threshold voltages less than or equal to 0.5 V;
- wherein the well potential of the MOSFETs constituting said CMOS circuit is subjected to a pulse variation;
- and
- wherein the substrate voltage of said dynamic memory cell is substantially a DC supply voltage.
3 more elements
A semiconductor device, comprising:
- a static memory cell which is operated with a first operating voltage, said static memory cell including a plurality of MOSFETs of a first threshold voltage;
- and
- a CMOS circuit which is operated with a second operating voltage that is lower than said first operating voltage, said CMOS circuit including a plurality of MOSFETs of a second threshold voltage that is lower than said first threshold voltage;
- wherein the well potential of the MOSFETs in said CMOS circuit are subjected to pulse variation.
1 more element
A semiconductor device, comprising:
- a CMOS circuit;
- a standby control circuit;
- a voltage conversion circuit;
- wherein an output voltage generated by said voltage conversion circuit is supplied to said standby control circuit, and wherein said standby control circuit varies the well potential of said CMOS circuit using said output voltage, depending on an operating condition of said semiconductor device;
- and
- a capacitor having a capacitance that is greater than the capacitance of said well, said capacitor being connected to the output of said voltage conversion circuit.
3 more elements
A method of operating a semiconductor device, comprising the following steps:
- applying a well voltage to the well of a plurality of MOSFETs of a CMOS circuit, said plurality of MOSFETs having respective threshold voltages less than or equal to 0.5 V;
- and
- applying a supply voltage to the CMOS circuit after the well voltage applying means begins to apply the well voltage.
A method of operating a semiconductor device, comprising the following steps:
- inputting a first voltage to a voltage conversion circuit, and outputting therefrom a second voltage derived from said first voltage to the well of a plurality of MOSFETs of a CMOS circuit, wherein the plurality of MOSFETs have respective threshold voltages less than or equal to 0.5 V;
- and
- applying a third voltage as a supply voltage to the CMOS circuit;
- wherein the step of applying the third voltage to the CMOS circuit is begun after the first voltage is input to the voltage conversion circuit.
1 more element
A method of operating a semiconductor device, comprising the following steps:
- fixing the well potential of a CMOS circuit having a plurality of MOSFETs having respective threshold voltages less than or equal to 0.5 V;
- and
- varying the well potential of said plurality of MOSFETs by capacitive coupling according to the variation of an input signal of said CMOS circuit.
A method of operating a semiconductor device, comprising the following steps:
- supplying an output voltage from a voltage conversion circuit to a standby control circuit;
- and
- outputting the output voltage from the standby control circuit to a CMOS circuit, to vary the well potential of the CMOS circuit using said output voltage, depending on an operating condition of said semiconductor device;
- wherein a capacitor having a capacitance that is greater than the capacitance of said well is connected to the output of said voltage conversion circuit.
1 more element
Dependencies are inferred from the claim text.