Input termination circuitry with high impedance at power off

摘要

An input termination circuit includes a first and a second resistor each having a terminal respectively coupled to a first and a second input terminal of the input termination circuit, a first and a second transistor coupled in series between the first resistor and the second resistor, and a third transistor having two terminals respectively coupled to the control circuit and a node between the first and the second transistor. The gate of the third transistor is coupled to ground. The gates of the first and the second transistor are coupled to a control circuit that is adapted to provide a control signal to turn the first and the second transistor on or off.