Abstract: An input protection circuit protects semiconductor circuits from ESD voltages and excessive voltages. The protection circuit includes an input/output node, a resistor (or other resistive element), and a varistor. The resistor has a first end coupled to the input/output node and a second end coupled to a port of the protected circuit. The varistor has a first end coupled to a ground node and a second end coupled to the second end of the resistor. The electronic circuit is coupled to the second end of the resistor and the second end of the varistor.