In one embodiment, a constant-current generator is connected in series with a dependent (e.g., tail) device. A switched capacitor circuit connected to the gate of the dependent device is operated to (i) charge at least one capacitor of the switched capacitor circuit, (ii) use the at least one charged capacitor to adjust the gate voltage of the dependent device to drive the dependent current through the dependent device to be equal to the constant current through the constant-current generator, and (iii) direct the dependent and constant currents through source and sink current nodes.