Among other things, techniques and systems are provided to pre-charge a node of a primary circuit, such as a voltage regulator or bandgap voltage reference, via a start-up circuit. The node is charged to a specified voltage during a pre-charge operation that occurs while the primary-circuit is powered-off. The pre-charge operation comprises discharging a voltage from the node during a first portion of the pre-charge operation and re-charging the node to the specified voltage during a second portion of the pre-charge operation. In some embodiments, the specified voltage is substantially equivalent to a switching voltage of a drive transistor of the primary circuit.