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:
Mar. 04, 2003
Filed:
Nov. 10, 1998
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A correlated double sampled/programmable gain amplifier (CDS/PGA) is disclosed which is operable to precondition a CCD output analog signal. The CDS/PGA includes an operational amplifier that is configured in a sample hold operation. The single-ended input is first clamped by a switch ( ) to clamp the DC level therein for a given pixel. A switch ( ) then samples the reset level onto a sampling capacitor ( ), and a switch ( ) thereafter samples the video signal onto one plate of a capacitor ( ). The lower plates of the capacitors ( ) and ( ) are then equalized and the other plates thereof connected to the positive and negative inputs of the operational amplifier ( ). An offset is provided by a programmable DAC ( ) to account for the dark current offset. The output scale is adjusted or mapped by limiting the output between a negative and a positive reference input. The sampling capacitors ( ) and ( ) can be varied to vary the gain of the amplifier.