Electrostatic discharge (ESD) protection is provided for an integrated circuit. In an aspect, a dynamic region having doped regions is formed on an epitaxy layer and substrate, and interconnects contact the dynamic region. In an aspect, the dynamic region operates as a back-to-back SCR that snaps back in both positive and negative voltage directions. In an aspect the dynamic region operates as an SCR that snaps back in a positive voltage direction and operates as a simple diode in a negative voltage direction. In another aspect, the dynamic region operates as an SCR that snaps back in a negative voltage direction and operates as a simple diode in a positive voltage direction. ESD protection over an adjustable and wide positive and negative voltage range is provided by varying widths and positioning of various doping regions. Breakdown voltages, critical voltages and critical currents are independently controlled.