| 摘要 |
PROBLEM TO BE SOLVED: To provide an offset cancel amplifier which suppresses input capacitance and suppresses element dispersion or the influence of noise with high accuracy. SOLUTION: The offset cancel amplifier comprises a differential pair 102, 101, loading circuits M1, M2 common to the two differential pairs, an amplification step 103, and capacitors C1, C2. The capacitor C1 is connected to the gate of the transistor M5 of the differential pair 102, and during a first period of a data output period, an output voltage Vout and a reference voltage Vref are inputted into the gate of the differential pair 102. In a state where the capacitor C2 is shut off from the gate of a transistor M6, the output voltage Vout is stored in the capacitors C1, C2; and input voltage Vin is commonly inputted to the gate of the differential pair 101. During a second period, the capacitor C2 is shut off from the capacitor C1 and is connected to the gate of the transistor M6 of the differential pair 102; and the output voltage Vout and the reference voltage Vref are stored in the capacitors C1, C2. During a third period, the gate of the differential pair 102 is shut off from the supply of the output voltage Vout, the reference voltage Vref and inputs a stored voltage of the capacitors C1, C2, and the output voltage Vout and the input voltage Vin are inputted into the gate of the differential pair 101. COPYRIGHT: (C)2007,JPO&INPIT
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