| 摘要 |
The differential voltage amplifier circuit or comparator is used for analog-to-digital conversion. …<??>The amplifier comprises a first and second capacitive coupling type amplifiers (36, 37) in each of which an autozeroed mode period for setting an operating point and a signal amplifying mode period for amplifying an input voltage are alternately set up, and the autozeroed mode periods in said first and second amplifier are shifted from each other, first and second mode selector (31, 32) for alternately setting up the autozeroed mode and the signal amplifying mode in the amplifiers (36, 37), first and second signal selectors (38, 39) are provided corresponding to the amplifiers, the signal selectors (38, 39) alternately selecting a reference voltage (Vref) and an input signal voltage (Vin) to apply the selected signal to the amplifiers (36, 37), the first and second signal selectors further selecting the reference voltage corresponding to the autozeroed mode periods of the amplifiers (36, 37) and the input signal voltage corresponding to the signal amplifying mode periods, and a selector (40) for selecting the amplified signal output from the amplifiers (36, 37) when the amplifiers are in the signal amplifying mode. |
