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:
Jun. 11, 1996
Filed:
Oct. 04, 1994
Analog Devices, Inc., Norwood, MA (US);
Abstract
An intrinsic R2R resistance ladder digital to analog converter (DAC) includes a plurality of matched semiconductor ladder switches, one in each of the R and 2R legs of the R2R ladder. The ON resistance of each semiconductor switch being matched to constitute the resistance ladder of the DAC; the ladder switches being operated in response to the digital signal input to the DAC; a reference circuit including a reference semiconductor switch matched with the ladder switches responsive to a reference current to generate a reference voltage; and a voltage follower circuit for monitoring the reference voltage and adjusting the current through the ladder switches to match the voltage at each ladder switch with the reference voltage for precisely fixing the DAC analog output current as a proportion of the reference current in dependence upon the operation of the ladder switches by the digital input signal.