Differential voltage amplifier

An integrated circuit for A/D conversion comprising:

• a plurality of differential voltage amplifiers whose first input terminals are applied with an input signal voltage and those second input terminals are applied with different reference voltages, each of said differential voltage amplifiers including;
• first and second capacitive coupling type amplifying means each of which are alternately set in an autozeroed mode period for setting an operating point and a signal amplifying mode period for amplifying an input voltage, the periods of the autozeroed modes in said first and second amplifying means being shifted from each other;
• first and second mode selecting means for alternately setting up the autozeroed mode and the signal amplifying mode in said first and second capacitive coupling type amplifying means;
• first and second signal selecting means provided corresponding to said first and second capacitive coupling type amplifying means, said first and second signal selecting means alternately selecting a reference voltage and an input signal voltage to apply the selected signal to said first and second capacitive coupling type amplifying means, said first and second signal selecting means selecting the reference voltage corresponding to the autozeroed mode periods of said first and second capacitive coupling type amplifying means and the input signal voltage corresponding to the signal amplifying mode periods;
• and
• means for selecting the amplified signal output from said first and second capacitive coupling type amplifying means when said first and second capacitive coupling type amplifying means are in the signal amplifying mode.