In certain aspects of the disclosure, a protection circuit includes a first input/output (I/O) pin, a second I/O pad, a shunt clamp coupled to the first I/O pad, and a resistor coupled between the shunt clamp and the second I/O pad. The resistor has a first dynamic resistance at a voltage of 100 millivolts across the resistor, the resistor has a second dynamic resistance at a voltage of three volts across the resistor, and the second dynamic resistance is at least five times greater than the first dynamic resistance.