US 2008/0174362 A1 · VOLTAGE SUPPLY CIRCUIT AND CIRCUIT DEVICE

Abstract

A voltage supply circuit and a circuit device can reduce the noise in the output of the circuit when the power to the circuit is turned on and off and can shorten the time required to start or stop the operation of the circuit. When the supply of power to signal processing part 10 is started or stopped, reference voltage Vref supplied to signal processing part 10 is varied continuously to reduce the high-frequency noise in the output of signal processing part 10. Also, when the setpoint value of the waveform of reference voltage Vref is generated by digital signal processing in voltage setting part 30, the desired waveform can be generated without being limited by the values of the circuit elements or the circuit configuration. The output noise of signal processing part 10 can be reduced, and the time that reference time Vref varies can be shortened.

Claims14

Dependent claims

A voltage supply circuit that supplies a reference voltage to a circuit, comprising:

a voltage generating part that generates said reference voltage corresponding to an input digital signal;
and
a voltage setting part that outputs said digital signal, which continuously changes said reference voltage from a reference potential to a prescribed potential after the power supply is started, corresponding to a signal indicating the start of said supply of power to said circuit or corresponding to said digital signal, which continuously changes said reference voltage from said prescribed potential to said reference potential, before said power supply is stopped corresponding to a signal indicating the stopping of the supply of power to said circuit.

A circuit device comprising:

a signal processing part that processes input signal on the basis of a reference voltage,
a voltage generating part that generates said reference voltage corresponding to the input digital signal;
a voltage setting part that outputs said digital signal, which continuously changes said reference voltage from a reference potential to a prescribed potential after the power supply is started, corresponding to one or both of the group consisting of a signal indicating the start of said supply of power to said signal processing part or corresponding to said digital signal, which continuously changes said reference voltage from said prescribed potential to said reference potential, before said power supply is stopped corresponding to a signal indicating the stopping of the power supply to said signal processing part.

Dependencies are inferred from the claim text.

Voltage supply circuit and circuit device

Life of this patent

Voltage supply circuit and circuit device

Life of this patent

Abstract

Claims14