Patent ID: 8908334

Claim:
A magneto-resistive (MR) sensor device comprising: an MR sensor having a safe operating voltage range, a normal operating voltage range within the safe operating voltage range, and two terminals coupled to a read channel circuit, including a positive terminal and a negative terminal; an MR sensor protection circuit having: a positive protection threshold voltage range outside of and above the normal operating voltage range and within the safe operating voltage range; a negative protection threshold voltage range outside of and below the normal operating voltage range and within the safe operating voltage range; a first N-channel field-effect transistor (NFET) that is coupled to the positive terminal and to the negative terminal, and configured to, in response to a voltage between the two terminals being within the positive protection threshold voltage range, limit the voltage between the terminals by shunting current between the positive terminal and the negative terminal, and; a second NFET that is coupled to the positive terminal and to the negative terminal, and configured to, in response to the voltage between the two terminals being within the negative protection threshold voltage range, limit the voltage between the terminals by shunting current between the positive terminal and the negative terminal.