Patent ID: 6965258
Filing Date: 2005-11-15
Classification: G11C

Abstract:
1. An apparatus for performing a sample-and-hold operation in each of a series of operational cycles that each include a sample phase followed by a hold phase, comprising: an input stage having an input for receiving an analog input signal, and having an output; a first capacitive storage device coupled to said input and said output; a switching device coupled to the first capacitive storage device, the switching device for establishing a coupling between the first capacitive storage device and the input during the sample phase in order to store in the first capacitive storage device for eliminating said coupling during the hold phase, the switching device further for causing the first capacitive storage device to store a final voltage upon completion of the hold phase; and a second capacitive storage device coupled to the switching device, the first and second capacitive storage devices having respective capacitances which are equal to one another, the switching device for establishing a coupling between the second capacitive storage device and the input during the sample phase in order to store in the second capacitive storage device said first voltage representative of the analog input signal, the switching device for eliminating said coupling during the hold phase, the switching device for effecting a charging of the second capacitive storage device to an inverted voltage upon completion of the hold phase, said switching device for connecting the second capacitive storage device to the first capacitive storage device during the sample phase in order to discharge the first capacitive storage device.