Abstract
Conventional CMOS charge pump circuits have some current mismatching characteristics. The current mismatch of the charge pump in the PLLs generates a phase offset, which increases spurs in the PLL output signals. In particular, it reduces the locking range in wide range PLLs with a dual loop scheme. A new charge pump circuit with perfect current matching characteristics is proposed. By using an error amplifier and reference current sources, one can achieve a charge pump with good current matching characteristics. It shows nearly perfect current matching characteristics over the whole VCO input range, and the amount of the reference spur is < –75 dBc in the PLL output signal. The charge pump circuit is implemented in a 0.25 µm CMOS process.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
