A High-Output-Swing and Low-Current-Mismatch Charge Pump for PLL

This paper introduces a charge pump with high output swing and low current mismatch for Phase-Locked Loop (PLL). By effectively addressing the channel length modulation effect and charge sharing effect through the use of rail-to-rail operational amplifier structures with single-stage and two-stage input configurations, the charging and discharging currents of the charge pump are perfectly matched. Under the TSMC 40nm process, the charge pump's current range is from <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{200}\boldsymbol{\mu}\mathbf{A}$</tex> to 3.8mA, and it can operate normally under a high-speed switching signal of 100MHz. With a supply voltage of 1.2V, the charge pump achieves a high output swing of 0.2V to 1.0V and a current mismatch of less than 0.022% across the entire current range.