A voltage regulator for a charge pump includes a capacitor divider and a reset circuit. The capacitor divider produces, based on an input voltage (VPP), a sample voltage at a sampling node. The sampling node and a reference voltage VREF are connected to respective inputs of a comparator that generates an enable signal for the charge pump. The reset circuit connects to the divider and includes a first transistor connected between the sampling node and a biasing node. During a sampling mode, the reset circuit biases VDS of the first transistor to approximately zero at the regulation point to minimize sub-threshold IDS. During reset intervals, the reset circuit applies VREF to the biasing node. The reset circuit may include a second transistor connected between the biasing node and a known level (e.g., ground) and a biasing transistor connected between the biasing node and VREF.