An apparatus can include a first circuit that is configured to provide electrostatic discharge (ESD) protection against an ESD pulse applied between a first node and a second node. The first circuit includes a series stack of bipolar transistors that are configured to shunt current between the first and second nodes in response to the ESD pulse; and a diode connected in series with the stack of bipolar transistors and configured to lower a snapback holding voltage of the first circuit when shunting current between the first and second nodes.