Presented is a self-tracking charge pump (ST-CP) that can deliver a non-constant current over the output voltage range for a fast-locking phase-locked loop (PLL). It features a simple self-bias self-tracking architecture that can reduce, simultaneously, the PLL locking time and the current mismatch in charge and discharge phases. Experimentally verified in a 0.18μm CMOS process, the proposed ST-CP achieves 72 reduction of PLL locking time compared with the conventional one. The core occupies 30×60μm and draws 10μA at 1.8V. © 2010 The Institution of Engineering and Technology.