The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Nov. 28, 2000

Filed:

Feb. 01, 1999
Applicant:
Inventor:

Hwey-Ching Chien, San Diego, CA (US);

Assignee:

Prominent Communications, Inc, San Diego, CA (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03L / ; H03L / ;
U.S. Cl.
CPC ...
331 17 ; 331 / ; 327536 ; 327537 ;
Abstract

A charge pump of a phase comparator in a phase locked loop is provided a latched comparator to minimize the effect of 'dead band' during the time between charging and discharging the loop filter of the charge pump. A latch is inserted between the charging or discharging amplifier and a reset switch which turns on either the charging amplifier or the discharging amplifier. The latch speed up the change over of the charging and discharging action due to regenerative action. The latch can be an asymmetrical flip flop with one inverter fed from a reference current source and a second inverter fed from an on/off current source as controlled by the sourcing command from the phase comparator.


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