Switching circuitry providing improved signal performance at high frequencies and method of operation thereof

Abstract

A switching circuitry and a switching method which reduces the influence of parasitic capacitance and provides improved signal performance at high frequencies. The circuitry may comprise a transistor having a source connected to an input node having an output resistance R , and a drain is connected to the output node having an input resistance R . The gate of the transistor is connected to a control node with output resistance R generating a control signal which opens or closes the transistor. By arranging that R >>R (and assuming that R ≧R ), high frequency circuitry characteristics are dramatically improved, and the circuit provides high frequency voltage gain approaching unity and phase shift between the output and input voltages approaching zero to reduce signal degradation. Alternative arrangements may employ bipolar, FET, or MOS transistors or transistor pairs. The switching circuitry has numerous applications, e.g. in power down circuits, video or telephone switches, or any other application where the required frequency of switching may be lower than the transmitted frequency.