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:
Apr. 12, 2005
Filed:
Dec. 18, 2003
Don C. Devendorf, Carlsbad, CA (US);
Erick M. Hirata, Torrance, CA (US);
Lloyd F. Linder, Agoura Hills, CA (US);
Christopher B. Langit, Gardena, CA (US);
Roger N. Kosaka, Torrance, CA (US);
Don C. Devendorf, Carlsbad, CA (US);
Erick M. Hirata, Torrance, CA (US);
Lloyd F. Linder, Agoura Hills, CA (US);
Christopher B. Langit, Gardena, CA (US);
Roger N. Kosaka, Torrance, CA (US);
TelASIC Communications, Inc., El Segundo, CA (US);
Abstract
A DAC () including an operational amplifier () having an input terminal; a plurality of current paths coupled to the input terminal; a plurality of current sources (I/2 -I/2); and an arrangement () for switchably coupling current from at least two of the cells to a respective one of the paths in response to an input signal. In a specific embodiment, the inventive DAC () further includes a first resistive element (RR) disposed in each of the current paths, a second resistive element (R-R) disposed between the current paths, and a feedback resistor (R) disposed between an output terminal of the amplifier and the input terminal thereof. In the illustrative embodiment, the coupling arrangement includes a plurality of switches (SW-SW); each of the switches is adapted to switch half of the current from a first source and half of the current from a second source into a respective one of the paths. The invention is adapted to lower the distortion of digital to analog converters by improving differential nonlinearities and integral nonlinearities, caused primarily by current source gradient errors, without the need for trimming.