A semiconductor device is described that includes one or more electrostatic discharge (ESD) protection circuits. Each circuit comprises reverse-biased steering diodes connected in series between power rail and signal ground, a bypass Zener diode and a substrate Zener diode. The Zener diodes provide ESD protection and the steering diode cooperate with the substrate Zener diode to provide a bypass function that is substantially symmetric about the signal ground. Noise in the circuit can be shunted using internal and/or external capacitances that can be implemented as Zener diodes.