Frequency synthesizer and charge pump circuit used therein

Details Frequency synthesizer and charge pump circuit used therein Frequency synthesizer and charge pump circuit used therein

2005-12-28

2009-08-25

Cox, Cassandra (Department: 2816)

Miscellaneous active electrical nonlinear devices, circuits, and

Signal converting, shaping, or generating

Synchronizing

C327S148000, C327S536000

Reexamination Certificate

active

07579888

ABSTRACT:
There are included a signal generating circuit (8) that generates, based on a comparison signal outputted from a phase comparator (3) and a clock signal outputted from a crystal oscillation circuit (1) and having a shorter pulse width than the comparison signal, a control signal obtained from a logical product of the two signals; and a charge pump circuit that performs, based on the control signal from the signal generating circuit (8), a charging or discharging operation of a capacitor. The charging or discharging operation of the capacitor is gradually performed little by little based on the control signal having the shorter pulse width than the conversional comparison signal, whereby even if the capacitance value of the capacitor is reduced, the substantial time constant can be enlarged, resulting in a stable operation of a frequency synthesizer.

REFERENCES:
patent: 5475326 (1995-12-01), Masuda
patent: 5929677 (1999-07-01), Murata
patent: 2005-252930 (2005-09-01), None

Affiliated with

Also associated with

Rating

Frequency synthesizer and charge pump circuit used therein does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Frequency synthesizer and charge pump circuit used therein, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Frequency synthesizer and charge pump circuit used therein will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-4140327