The charge pump (CP) circuit is a key element in aphase-locked loop (PLL). Its function is to transform the Up andDown signals from the phase/frequency detector into current. InCMOS CPs, which have Up and Down switches made of p-channelMOS and n-channel MOS, respectively, a current mismatchoccurs when dumping the charge to the loop filter. This currentmismatch of the CP in the PLL generates fluctuations in thevoltage-controlled-oscillator input and subsequently, a large phasenoise on the PLL output signals. In this brief, a new CP with goodcurrent matching characteristics is proposed. By using a simplegain-boosting circuit, good current matching characteristics canbe achieved with less than 0.1% difference of the Up/Down currentover the CP output voltage ranges of 0.8–2.2 V and 0.5–1.2 V on0.35μm 3.3-V and 0.18μm 1.8-V CMOS processes, respectively.The proposed CP circuit is simulated and verified by HSPICEwith 0.35μm 3.3-V and 0.18μm 1.8-V CMOS parameters.