Analog switch structure having low leakage current
AssigneeMotorola, Inc.
InventorsRichard W. Ulmer, James A. McKenzie
Life of this patent
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Abstract
An analog switch structure which utilizes three switches and has low leakage current is provided. A first switch couples an input terminal to a node in response to a control signal. A second switch connects the node to an output terminal in response to the control signal. A buffer circuit is connected to the output terminal for providing a buffered output signal. A third switch is connected between the buffered output signal and the node to selectively connect the buffered output signal to the node, thereby maintaining zero voltage potential across the second switch.
Claims10
An analog switch structure having low leakage current comprising:
- first switching means for coupling an input terminal to a node in response to a control signal means;
- second switching means connected to the node for coupling the node to an output terminal in response to said control signal means;
- buffer means having an input connected to the output terminal, and an output for providing a buffered output signal;
- and
- third switching means connected between the node and the output of the buffer means, inversely responsive to said control signal means, for connecting the buffered output signal to the node.
A method of substantially reducing the amount of leakage current in an analog switch structure, comprising the steps of:
- connecting first and second switches in series to selectively couple an input terminal to an output terminal in response to a control signal;
- and
- providing means to controllably maintain the voltage potential across the second switch at substantially zero volts in response to a complement of the control signal.
A multiplexed analog switch structure having low leakage current comprising:
- first switching means for coupling an input terminal to a node in response to a control signal;
- second switching means connected to the node for coupling the node to an output terminal in response to said control signal;
- buffer means having an input connected to the output terminal, and an output for providing a buffered output signal;
- third switching means connected between the node and the output of the buffer means, inversely responsive to said control signal, for connecting the buffered output signal to the node;
- and
- a plurality of multiplexed input switch stages for coupling a predetermined one of a plurality of input voltages to the output terminal in response to a predetermined one of a plurality of control signals, wherein the first, second and third switching means and the buffer means comprise an input switch stage.
Dependencies are inferred from the claim text.