Circuit design technique for increasing the bandwidth of sample-and-hold circuits in flash ADCs
AssigneeTexas Instruments Incorporated
InventorsKrishnasawamy Nagaraj, David A. Martin
Life of this patent
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Abstract
An analog-to-digital converter to convert an analog signal to a digital signal, including a sample-and-hold circuit to sample and hold the analog signal and to output a held signal, a buffer circuit to buffer the held signal to output a buffered signal, and a comparator circuit to compare the buffered signal with a reference voltage.
Claims4
An analog-to-digital converter to convert an analog signal to a digital signal, comprising:
- a sample-and-hold circuit to sample and hold said analog signal and to output a held signal;
- a buffer circuit to buffer said held signal to output a buffered signal;
- a comparator circuit connected to said buffer circuit to compare said buffered signal with a reference voltage;
- and
- a switch connecting the input of said comparator circuit to a reference voltage,
- wherein said buffer circuit is a two-transistor circuit including a source follower transistor and a current source transistor.
An analog-to-digital converter to convert an analog signal to a digital signal, comprising:
- a sample-and-hold circuit to sample and hold said analog signal and to output a held signal;
- a buffer circuit to buffer said held signal to output a buffered signal;
- a comparator circuit connected to said buffer circuit to compare said buffered signal with a reference voltage;
- and
- a switch connecting the input of said comparator circuit to a reference voltage,
- wherein said buffer circuit is an analog tristate.
An analog-to-digital converter to convert an analog signal to a digital signal, comprising:
- a sample-and-hold circuit to sample and hold said analog signal and to output a held signal;
- a buffer circuit to buffer said held signal to output a buffered signal;
- a comparator circuit connected to said buffer circuit to compare said buffered signal with a reference voltage;
- and
- a switch connecting the input of said comparator circuit to a reference voltage,
- wherein said buffer circuit is a field effect transistor (FET) having a gate connected to said sample-and-hold circuit.
Dependencies are inferred from the claim text.