JPS57180221A - Switched capacitor - Google Patents

Abstract

PURPOSE:To decrease the leakage of a clock signal, by adding a clock signal in opposite phase with a leaked clock signal appeared at the output of a switched capacitor to the output side. CONSTITUTION:A switch 1 consists of N-MOSFETs 6 and 7 and an inverter 8, a clock signal is applied to a gate of the FET6 from a terminal 5 and to a gate of the FET 7 via the inverter 8 to alternately turn on and off the FETs 6 and 7, and an input signal from a terminal 3 is outputted at a terminal 4 while repeating charge/discharge to a capacitor 2. A compensation MOSFET 10 having the same capacitance as the capacitance between the gate and source of the FET 7 is provided at the output side of the FET 7, the clock signal is applied to the gate to generate a clock signal in opposite phase with the leaked clock signal from the FET 7 at the output side. Thus, the leaked clock signals are cancelled, allowing to reduce the leakage of clock of the switched capacitor.