Patent ID: 6741192
Filing Date: 2004-05-25
Classification: H03M

Abstract:
An A/D conversion method for a serial/parallel A/D converter which compares an analog input voltage which randomly varies with time and a prescribed first reference voltage, to generate a first binary code, as well as compares a second reference voltage which is decided on the basis of the result of the comparison and the analog input voltage, to generate a second binary code, and performs a logic operation on the generated first and second binary codes, thereby generating a digital value, said method comprising:a sampling and initialization step of sampling the analog input voltage received, as well as initializing a previous second reference voltage to a prescribed initialization voltage; a first voltage comparison step of comparing the value of the analog input voltage which has been sampled in the sampling and initialization step and the first reference voltage, to generate the first binary code; and a second voltage comparison step of comparing the value of the second reference voltage which has been changed from the prescribed initialization voltage to a voltage which is decided on the basis of the result of the comparison in the first voltage comparison step, with the value of the analog input voltage which has been sampled in the sampling and initialization step, to generate the second binary code.