Embodiments of this disclosure relate to electrostatic discharge (ESD) protection techniques. For example, some embodiments include a variable resistor that selectively shunts power of an incoming ESD pulse from a first circuit node to a second circuit node and away from a semiconductor device. A control voltage provided to the variable resistor causes the transistor to change between a fully-off mode where only sub-threshold current, if any, flows; a fully-on mode wherein a maximum amount of current flows; and an analog mode wherein an intermediate and time-varying amount of current flows. In particular, the analog mode allows the ESD protection device to shunt power more precisely than previously achievable, such that the ESD protection device can protect semiconductor devices from ESD pulses.