INPUT STAGE PROTECTION CIRCUIT FOR A RECEIVER

摘要

An extraneous voltage protection circuit and method transforms an overvoltage input signal or undervoltage input signal to a suitable voltage level for a protected circuit. An input voltage dependent variable reference voltage is used to protect overvoltage protection circuitry against unsuitable undervoltage conditions. In one embodiment, an overvoltage protection circuit, an undervoltage protection circuit, and an input voltage dependent variable reference voltage source is made of single gate oxide MOS devices.