A pre-charging circuit, such as can be used to pre-charge a data bus, is largely process independent. A push-pull type of arrangement is used, where the output of the pre-charge circuit is initially connected to a supply level through one transistor, then connected to ground by another transistor. These transistors can be controlled by one or more comparators that have as inputs a reference level and feedback from the output. The reference level is generated by a circuit that tracks the threshold voltage of the other devices in the circuit in order to reduce process dependency of the output level. The circuit can also include a device to provide an extra VDD assist to the output.