Charge pump with reduced current mismatch

Miscellaneous active electrical nonlinear devices – circuits – and – Signal converting – shaping – or generating – Synchronizing

Reexamination Certificate

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

C327S148000, C327S158000

Reexamination Certificate

active

07902888

ABSTRACT:
Charge pump circuitry is provided that is insensitive to charge sharing and current mismatch effects. The charge pump circuitry has an output node at which a charge pump output voltage is provided. A first current source charges the output node to increase the output voltage or a second current source discharge the output node to decrease the output voltage. The charge pump circuitry uses a unit-gain op-amp circuit to prevent charge sharing effects from affecting the output voltage when switching between discharging and charging operations. A low-pass filter is used to reduce feedback noise on the output node. A replica feedback circuit prevents current mismatch between the currents produced by the first and second current sources. The first and second current sources may be formed using programmable transistors that are adjusted by static control signals provided by programmable elements to further minimize current mismatch.

REFERENCES:
patent: 5608348 (1997-03-01), Kearney et al.
patent: 5760640 (1998-06-01), Girard et al.
patent: 5952869 (1999-09-01), Fattori et al.
patent: 6094078 (2000-07-01), Suzuki
patent: 6157265 (2000-12-01), Hanjani
patent: 6404276 (2002-06-01), Liu
patent: 6526111 (2003-02-01), Prasad
patent: 6545540 (2003-04-01), Enriquez
patent: 6639475 (2003-10-01), Ichimaru
patent: 6774730 (2004-08-01), Gasparik
patent: 6778026 (2004-08-01), Cheah et al.
patent: 6924678 (2005-08-01), Starr
patent: 6952126 (2005-10-01), Byun et al.
patent: 7012473 (2006-03-01), Kokolakis
patent: 7042302 (2006-05-01), Chien
patent: 7053684 (2006-05-01), Sen et al.
patent: 7161401 (2007-01-01), Li
patent: 2005/0068075 (2005-03-01), Innocent
patent: 2005/0185746 (2005-08-01), Jung
patent: 2005/0253634 (2005-11-01), Wu
Jae-Shin Lee et al., “Charge Pump With Perfect Current Matching Characteristics in Phase-Locked Loops”, Electronics Letters, vol. 36, No. 23, pp. 1907-1908 (Nov. 9, 2000).
Ian A. Young et al. “A PLL Clock Generator with 5 to 110 MHz of Lock Range for Microprocessors”, IEEE J. Solid State Circuits, vol. 27, No. 11, pp. 1599-1607 (1992).

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Charge pump with reduced current mismatch does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Charge pump with reduced current mismatch, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Charge pump with reduced current mismatch will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-2690705

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.