| 摘要 |
A sample and hold circuit having a single-ended input and a differential output. Switching circuitry operates to couple first and second input capacitors to the single-ended input and to a reference voltage, respectively, when in a sample mode. The switching circuitry also operates in the sample mode to connect a first pair of feedback capacitors between the inputs and outputs of a differential amplifier and to connect a second pair of capacitors between known reference voltages. During the hold mode, the switching circuitry causes the charge present on the input capacitors to be transferred equally to the second pair of feedback capacitors so that the output of the differential amplifier is a differential representation of the single-ended input. At the beginning of the subsequent sample mode, the switching circuitry causes the charge on the second pair of feedback capacitors to be transferred to the first pair so that same differential representation will be present at the output when a new input is being connected to the first and second input capacitors.
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