New low current mismatch and wide output dynamic range charge pump

Conventional charge pumps suffer from current mismatch that increases reference spur in Phase Locked Loops (PLL). Some previously introduced methods reduce this mismatch by cost of output voltage dynamic range limitation. This paper proposes a new charge pump structure with low current mismatch while having wide output dynamic range. High accurate current matching is done using high-gain low power amplifiers in feedback configuration where it’s wide output dynamic range is obtained by using triode-region transistors in current mirrors. Circuit level simulation results in standard 0.18μm CMOS technology with 1.8 V supply voltage has been provided to verify the effectiveness of the proposed structure

Keywords:

charge pump , spur suppression , current mismatch