ANALOG-DIGITAL CONVERTER CIRCUIT AND ANALOG-DIGITAL CONVERSION METHOD
Provided is an analog-digital converter circuit including: a comparison unit that sequentially compares an analog input voltage with reference voltages, which sequentially vary, and outputs a comparison result as a digital value; a standard voltage generation unit that generates a standard voltage for correcting the reference voltages; a storage unit that stores a comparison result of the standard voltage obtained by the comparison unit; and a reference voltage generation unit that generates the reference voltages based on the comparison result of the standard voltage.
1 . An analog-digital converter circuit comprising:
a comparison unit that sequentially compares an analog input voltage with a plurality of reference voltages and outputs a comparison result as a digital value;
a standard voltage generation unit that generates a standard voltage for correcting the reference voltages;
a storage unit that stores a comparison result of the standard voltage obtained by the comparison unit; and
a reference voltage generation unit that generates the reference voltages corrected based on the comparison result of the standard voltage.
2 . The analog-digital converter circuit according to claim 1 , wherein the reference voltages are generated from a power supply voltage.
3 . The analog-digital converter circuit according to claim 2 , wherein the standard voltage is substantially constant independently of a variation of the power supply voltage.
4 . The analog-digital converter circuit according to claim 2 , wherein the reference voltage generation unit generates the reference voltages, the reference voltages being substantially constant independently of a variation of the power supply voltage.
5 . The analog-digital converter circuit according to claim 1 , wherein the reference voltage generation unit comprises:
a digital signal generation circuit that generates digital signals respectively corresponding to the reference voltages based on the comparison result of the standard voltage; and
a digital-analog converter circuit that converts the digital signals into the reference voltages.
6 . The analog-digital converter circuit according to claim 5 , wherein the digital-analog converter circuit is a resistor string type digital-analog converter circuit.
7 . An analog-digital conversion method comprising:
converting a standard voltage into a digital value, the standard voltage being substantially constant independent of a variation of a power supply voltage;
generating a plurality of reference voltages corrected based on a comparison result of the standard voltage; and
sequentially comparing the plurality of reference voltages with an analog input voltage and converting the analog input voltage into a digital value.
8 . The analog-digital conversion method according to claim 7 , wherein the reference voltages are generated from the power supply voltage.
9 . The analog-digital conversion method according to claim 7 , wherein the reference voltages substantially constant independently of the variation of the power supply voltage are generated.
10 . The analog-digital conversion method according to claim 7 , wherein the generating the plurality of reference voltages includes:
generating digital signals respectively corresponding to the reference voltages based on the comparison result of the standard voltage; and
converting the digital signals into the reference voltages.