Patent ID: 6707413
Filing Date: 2004-03-16
Classification: H03M

Abstract:
An A/D converter comprising:a reference voltage generation section for generating a plurality of reference voltages; a differential amplification section for amplifying a voltage difference between each of the plurality of reference voltages and an input signal voltage so as to generate a plurality of output voltage sets, each of the plurality of output voltage sets including complementary non-inverted and inverted output voltages; and an operating section for receiving the plurality of output voltage sets, the operating section being operated according to a clock signal, wherein the operating section includes a comparison section having a threshold voltage Vtn, the comparison section includes an input transistor section to which first and second output voltage sets of the plurality of output voltage sets are input, and a positive-feedback section operating according to the clock signal, the first output voltage set includes a first non-inverted output voltage and a first inverted output voltage, and the second output voltage set includes a second non-inverted output voltage and a second inverted output voltage, the input transistor section performs a prescribed weighting calculation so as to determine the threshold voltage Vtn, and compares a difference between the first non-inverted output voltage and the first inverted output voltage with a difference between the second non-inverted output voltage and the second inverted output voltage so as to output a comparison result to the positive-feedback section, and the positive-feedback section amplifies the comparison result output by the input transistor section when the clock signal is at a prescribed level and retains the amplified comparison result while outputting the amplified comparison result as a digital signal.