| 摘要 |
PURPOSE:To cancel offset voltage by connecting MOSFETs to which fixed gate voltage and variable gate voltage are supplied respectively in parallel with MOSFETs to be used as load circuits for diffential MOSFETs respectively. CONSTITUTION:The input voltage V<in> and output voltage VOUT of an amplifier 1 are compared by a comparator 2 and the compared result is read in the succeeding up/down counter 3. A switch selecting circuit 4 is actuated on the basis of the output of the counter 3 to select supply voltage B to the amplifier 1. The amplifier 1 consists of differential MOSFETs M3, M4, MOSFETs M1, M2 to be used as their load circuits and MOSFETs M11, M12 connected in parallel with the FETs M1, M2 and inputting fixed gate voltage A and variable gate voltage B and is allowed to cancel offset between the input and output voltages.
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