Invariant sample-and-hold amplifier to the hold capacitor discharge

The conventional measurement signal sample-and-hold amplifier comprising a sample and hold circuit in the form of a sample switch, a voltage hold capacitor, and a voltage repeater further includes two similar sample-and-hold circuits of reference voltages. The idea of the proposed amplifier is that hold capacitors are equally discharged in all three sample-and-hold circuits. Therefore, an affine ratio for the stored three voltage samples does not change the intrinsic value over a long discharge time. Then, this invariant affine ratio is taken as the measuring signal. A reproducing (recovery) unit, which is also included, calculates this affine ratio. In turn, the included information signal former shaper pre-converts (prepares) the initial measurement signal using reference voltages. Thus, the hold time is significantly increased, while maintaining a short sample time for the given hold capacitor. On the other hand, the affine ratio uses differences and voltage ratios. Therefore, offset errors are mutually reduced. It is possible to implement the proposed sample-and-hold amplifier in the form of an analog chip based on a multiplier and the known multi-channel sample-and-hold amplifier.