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:
Oct. 02, 2007
Filed:
Nov. 21, 2005
Circuit topology for reduced harmonic distortion in a switched-capacitor programmable gain amplifier
Loren Justin Tomasi, Chandler, AZ (US);
Loren Justin Tomasi, Chandler, AZ (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
A switched-capacitor programmable gain amplifier (PGA) has improved circuit performance that avoids impracticably small capacitors, while providing low total harmonic distortion (THD) and reasonable gain linearity. The sampling capacitor (CS) in the PGA is designed with a C-2C capacitor array. Gain settings from the C-2C capacitor array arranged for selection with constant VGS switches. The gain of the resulting PGA corresponds to the ratio of the effective capacitance of the C-2C array and the effective capacitance value of the feedback capacitor (CF). The resulting performance of the PGA has reduced charge injection and clock feed-through errors, and thus reduced THD.