초록 ▼

When the performance of an A/D converter required by a system changes, power consumption of the overall system can be reduced. The resolution of an A/D converter is made variable by changing a current flowing through an amplifier by an external control signal that specifies the resolution. Thus, whe

When the performance of an A/D converter required by a system changes, power consumption of the overall system can be reduced. The resolution of an A/D converter is made variable by changing a current flowing through an amplifier by an external control signal that specifies the resolution. Thus, when the performance required by a system changes, it is possible to change the performance of the A/D converter and to prevent a performance overhead of the A/D converter. Consequently, power consumption of the A/D converter is reduced, and power consumption of the system as a whole is also reduced.

대표청구항 ▼

1. A signal processing device comprising: an A/D converter including an amplifier, wherein the resolution of said A/D converter is made variable by changing a current flowing through the amplifier with a control signal that specifies the resolution; a signal processing means in which part of th

1. A signal processing device comprising: an A/D converter including an amplifier, wherein the resolution of said A/D converter is made variable by changing a current flowing through the amplifier with a control signal that specifies the resolution; a signal processing means in which part of the performance is determined by the resolution of the A/D converter; and a monitoring means for monitoring the performance of the signal processing means attributable to the resolution of the A/D converter and instructing the A/D converter to increase the resolution if a decrease of the performance is detected and to reduce the resolution if an overhead of the performance is detected. 2. The signal processing device according to claim 1, wherein: the signal processing means is a digital demodulator circuit; and the performance is a bit error rate of the digital demodulator circuit. 3. A signal processing device comprising: an A/D converter comprising: a controlling means for determining a resolution;an amplifier for changing a current with a signal from the controlling means; anda voltage comparator array to which an output from the amplifier is input; wherein the resolution is corrected by inputting the result of the comparison in the voltage comparator array into the controlling means; a signal processing means in which part of the performance is determined by the resolution of the A/D converter; and a monitoring means for monitoring the performance of the signal processing means attributable to the resolution of the A/D converter and instructing the A/D converter to increase the resolution if a decrease of the performance is detected and to reduce the resolution if an overhead of the performance is detected. 4. The signal processing device according to claim 3, wherein: the signal processing means is a digital demodulator circuit; and the performance is a bit error rate of the digital demodulator circuit. 5. A method of A/D conversion, comprising: a voltage-inputting step of inputting a test voltage in an amplifier; a comparing step of comparing the voltage that is output from the amplifier with the test voltage; and a resolution-determining step of adjusting a current value of the amplifier according to the result obtained in the comparing step. 6. The method of A/D conversion according to claim 5, wherein the resolution-determining step increases the current value of the amplifier if the result obtained in the comparison step is higher than a predetermined threshold value, and decreases the current value of the amplifier if the result obtained in the comparison step is lower than the predetermined threshold value.