Translating switch circuit with disabling option

摘要

A translation switch is described with a transfer MOS transistor that connects a first node to second node where the first node is referenced to a higher voltage than is the second. A pseudo-rail generator drives the gate of the MOS transistor and provides a p-rail reference voltage lower in voltage to that of the first node. The generator includes a selectively enabled active clamping circuit that clamps the gate of the MOS transfer transistor to the p-rail potential and sinks current from the p-rail when higher voltages appear on the p-rail to thereby maintain the p-rail at a substantially constant potential.