A method and an apparatus for biasing a charge pump in a phase locked loop in a circuit and generally for biasing a circuit through the use of a replica circuit. The method and apparatus make use of a replica circuit including substantially similar circuit elements to those circuit elements making up the circuit to be biased. Through the use of comparison and bias techniques, the replica circuit and the circuit to be biased are both biased. The bias conditions result from a comparison of the operation of the replica circuit and the circuit to be biased. Since the replica circuit operates in a manner substantially similar to an expected operation mode of the circuit to be biased, the bias conditions resulting from the comparisons will cause the circuit to be biased to operate similarly to how the replica circuit operates, while still handling external influences such as loading. Currents of two current sources within the circuit to be biased are equalized by biasing of one of the current sources responsive to the operation of both the circuit to be biased and a replica circuit. This equalization reduces the amount of error current erroneously added to or subtracted from a loop filter as a result of unequal currents flowing through the two current sources.