| 摘要 |
A system for enabling a capacitor to track an analog input signal and hold the signal level, on command. The system includes a high speed operation amplifier having first and second independent and selectable pairs of differential inputs. The amplifier output is connected through a pair of diodes connected in inverse parallel to the capacitor. Feedback means couple the capacitor to one pair of inputs in the track mode in a manner such that the high amplifier gain compensates for nonlinearities and offset effects to enable the capacitor to precisely track the input signal. In the hold mode, the other pair of inputs is selected to enable the amplifier to act as a unity gain voltage follower providing an output substantially equal to the capacitor voltage and insufficient to exceed the forward threshold of the diodes.
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