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.
Patent No.:
Date of Patent:
Nov. 04, 2003
Filed:
Sep. 04, 2002
Rodney A. Hughes, Tacoma, WA (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
A charge pump for injecting a charging current onto a loop filter when a pump control signal is enabled. The charge pump comprises: i) MOS output transistors for injecting or removing the charge onto the loop filter; ii) pre-charge capacitors for storing pre-charge voltages at least equal to the desired gate-to-source voltages of the output transistors; and iii) switching circuitry for coupling the pre-charge capacitors to the gates of the output transistors when the Pump Up and/or Pump Down signals are enabled. The appropriate pre-charge voltage turns on the appropriate output transistor and the charging and/or discharging current is adjusted to a final level determined by the desired gate-to-source voltages and monitoring circuits.