Limit swing charge pump and method thereof

Details Limit swing charge pump and method thereof Limit swing charge pump and method thereof

2002-07-12

2004-11-16

Callahan, Timothy P. (Department: 2816)

Oscillators

Automatic frequency stabilization using a phase or frequency...

Particular error voltage control

C327S536000

Reexamination Certificate

active

06819187

ABSTRACT:

TECHNICAL FIELD
An aspect of this invention relates to charge pumps.
BACKGROUND
A charge pump circuit used in a Phase Lock Loop (PLL) generates an error signal based on a phase difference between two inputs. Within the charge pump circuit, both charge and discharge currents flow. Transient errors may occur in the output current of the charge pump circuit due to asymmetries between the charge and discharge currents. When the charge pump circuit is included in a PPL, the transient error in the output current may cause an increase in reference spurs near the carrier frequency.
SUMMARY
A charge pump comprising a charge pump core including output switches. The charge pump core, in response to a drive signal, to generate a charge pump output. A limit swing generator, in response to an input signal, to generate the drive signal to control the charge pump core. The drive signal having voltage levels including a high level and a low level. The limit swing generator including at least one voltage generator to control the voltage levels of the drive signal such that the drive signal tracks a process variable of the output switches.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below.


REFERENCES:
patent: 4430641 (1984-02-01), Baur et al.
patent: 5066871 (1991-11-01), Wilcox
patent: 5359299 (1994-10-01), Webster
patent: 5392205 (1995-02-01), Zavaleta
patent: 5629843 (1997-05-01), Loughmiller et al.
patent: 6160723 (2000-12-01), Liu
patent: 6208197 (2001-03-01), Ternullo, Jr. et al.
patent: 6278317 (2001-08-01), Hsu et al.
patent: 6313707 (2001-11-01), Fischer et al.
patent: 6566846 (2003-05-01), Voo
patent: 2002/0036538 (2002-03-01), Choi
IEEE std. 802.11b—1999,Sponsor LAN MAN Standards Committee of IEEE Computer Society,“Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications, Higher-Speed Physical Layer Extension in 2.4 GHz Band”.

Affiliated with

Also associated with

Rating

Limit swing charge pump and method thereof does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Limit swing charge pump and method thereof, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Limit swing charge pump and method thereof will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3327060