Patent ID: 6278395
Filing Date: 2001-08-21
Classification: H03M

Abstract:
An A/D converter which analog-to-digital converts an analog input voltage to output a digital output voltage, comprising:a reference conversion voltage output portion for converting said analog input voltage on the basis of a plurality of reference voltages to output a plurality of reference conversion voltages;an intermediate voltage generating portion having a predetermined number of resistance units respectively provided between one voltage and the other voltage in pairs of said predetermined number of said reference conversion voltages in said plurality of reference conversion voltages, for generating a plurality of intermediate voltages by resistance division using said predetermined number of resistance units and outputting a plurality of conversion voltages including said plurality of intermediate voltages; anda digital data output portion for outputting the digital output voltage on the basis of said plurality of conversion voltages,wherein each of said predetermined number of resistance units in said intermediate voltage generating portion comprises,a first input terminal connected to said one voltage,a second input terminal connected to said other voltage,a plurality of resistor elements having the same resistance value, said plurality of intermediate voltages including at least part of voltages obtained from one end of each of said plurality of resistor elements, anda resistor connecting wiring provided so as to connect said plurality of resistor elements in series between said first and second input terminals,and wherein in all of said predetermined number of resistance units, said resistor connecting wiring is arranged so that the range between said one voltage and said other voltage is uniformly divided by said plurality of resistor elements in consideration of resistance component accompanying said resistor connecting wiring.