Patent ID: 6956412

Claim:
A high-voltage input tolerant receiver adapted to receive an external signal varying between a ground potential and a defined voltage limit for the receiver, the receiver being designed to output an internal signal varying between the ground potential and a voltage less than the defined voltage limit for the receiver, comprising: a pad which receives the external signal; a control circuit that receives the external signal from the pad and outputs a first control signal and a second control signal when the external signal is higher than a first voltage; a first clamp circuit that receives the external signal from the pad, outputs an intermediate signal equivalent to the external signal, and clamps the intermediate signal to a second voltage lower than the first voltage in response to receiving the first control signal; a level keeper circuit that pulls the intermediate signal up to a third voltage less than or equal to the first voltage in response to receiving the second control signal; and a buffer circuit that receives the intermediate signal and outputs the internal signal.