Wide Common Mode Range Transmission Gate

Abstract

A transmission gate (200) self-biases its transistors (220, 240, 250, 260) to provide a constant gate bias that provides for an input signal to be passed cleanly to the A consistent path for the output of the gate (210) and protects the gate oxide of the transistor in the presence of a high input signal. An array of matching transistors (220, 240, 250, 260) arranged to pass a voltage input node (230) and biased by a current source (270) configured to cross the matching transistors (230). The individual transistors (240, 250) of the 220, 240, 250, 260) array provide the bias current. A current sink (280) is configured to sink the bias current across the individual transistors (240, 250) to set the bias voltage at the voltage input node (230) to the matching transistors (220, 240, 250, 260) multiples of the gate-to-source voltages of the individual transistors (240, 250) of the array. Different sets of transistors (220, 260) are configured to provide signal paths for analog input signals.

Description

technical field [0001] The present invention generally relates to transmission gates. Background technique [0002] Various kinds of electronic devices are well known. Such electronic devices may send electronic signals between circuits or via the device to communicate information or trigger the operation of various elements. For example, modern automobiles contain a wide variety of electronic controls placed throughout the vehicle. Such devices may send signals to each other and / or to the vehicle's central computer for processing. To send such signals, switches transmit or block them to facilitate orderly communication. For example, transmission gates or analog switches may control the transfer of incoming signals to other devices or circuit elements. In one state, the transmission gate blocks the signal, and in the other state, the transmission gate passes the signal at its input to its output. [0003] figure 1 One way to handle this application is illustrated in f...

AI Technical Summary

Problems solved by technology

For example, when an input signal is too high, the input signal may be clamped or cut off because transistors 12 and 14 cannot physically handle this signal unless specifically designed and built to do so

Also, due to the parasitic diode effect on the PMOS transistor of the gate, the feedback signal may travel from the input to the output

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