PURPOSE: To output a difference voltage at one and same time continuously with simple constitution by holding the difference voltage via the 1st and 2nd capacitors controlled by clocks whose phases are deviated to each other and not overlapped.
CONSTITUTION: With a clock 1 at an H level, switches 3, 4 are turned on and the 1st capacitor 11 is charged in response to the difference of input voltages V1, V2 at one and same time. When the clock 1 goes to an L level, the switches 3, 4 are turned off, a difference voltage is sampled by a capacitor C1, and when the clock 2 not overlapped with the clock 1 goes to H, switches 5, 6 are turned on and one terminal of the capacitor C1 is connected to a zero level power supply 16. Then the difference voltage with respect to the zero level of the capacitor C1 charges the 2nd capacitor C2 whose one terminal is connected to ground in terms of AC via the switch 5, the clock 2 goes to L and held even after the switch 5 is turned off and the difference voltage is extracted continuously from an output terminal 18 via a buffer amplifier 17 with simple constitution.
IZAWA YUJI
FURUHATA MAKOTO
MINAMIMURA EIJI
