Described herein are a method, apparatus, and system for electrostatic discharge protection of supplies. The apparatus comprises a timer unit having a node with a first supply signal and operable to generate a first timer signal based on the first supply signal; and a clamp unit, coupled to the timer unit and having a node with a second supply signal, operable to clamp the second supply signal in response to electrostatic discharge (ESD) on the node with the second supply signal for a duration based on a signal level of the first timer signal.