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. 10, 2000
Filed:
Dec. 22, 1998
Mark V Wadsworth, Sierra Madre, CA (US);
Kirk D Peterson, Plano, TX (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
The speed performance of a resistive DAC can be improved by tailoring the selection switch size to the node location. For the simple case of a DAC used in a SAR-based ADC, the MSB code, which is activated during each SAR search, is the speed-limiting bit. Increasing the size of the switch on the node corresponding to the MSB will reduce the on-resistance of the FET and, therefore, the total resistance to ground from the node. The on-resistance can be changed markedly without substantially changing the total capacitance at the output node, since the sum of the parasitic from the remaining switches will far exceed the additional capacitance created by increasing the MSB FET.