| 摘要 |
PURPOSE:To attain high speed operation of a comparator and circuit integration by providing a switch short-circuiting a capacitor sampling an input voltage so as to reduce the discharge time of the capacitor. CONSTITUTION:Capacitors C1, C2 and inverters 1, 2 are connected in series, the capacitor C2 connected between the input and output of the inverters 1, 2 is short-circuited by a switch SW5 so as to constitute a voltage comparator circuit of two-stage cascade connection. Switches SW1, 2, 3, 5 of the circuit are closed in the order to store an input Vref to the capacitor C1, then the switches SW5, 2, 3, 1 are opened in the order and the switch SW4 is closed to impress other input Vin to the capacitor C1 and a high or low level voltage is outputted to the output side. Then the switch SW5 is added to discharge the capacitor C2 quickly so as to reduce the sampling time thereby quickening the operation of the voltage comparator. |
