A method of designing, for a magneto-resistive (MR) sensor, a protection circuit having a first and a second N-channel field-effect transistor (NFET) and at least one positive-negative (PN) diode is disclosed. The method may include determining a safe operating voltage range for the MR sensor and determining, within the safe operating voltage range, a normal operating voltage range for the MR sensor. The method may also include determining a protection threshold voltage range outside of the normal operating voltage range and within the safe operating voltage range of the MR sensor. The method may also include selecting device parameters to configure the first and second NFETs and the at least one PN diode to, in response to a voltage applied to the MR sensor being within a protection threshold voltage range, limit, by shunting current, the voltage applied to the MR sensor.