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. 04, 1985
Filed:
Dec. 31, 1981
David P Burton, Limerick, IE;
Analog Devices Incorporated, Norwood, MA (US);
Abstract
A signal-controllable attenuator comprising a 17-bit multiplying-type digital-to-analog converter having an R/2R ladder network to set the bit weights, and controlled by a 6-bit remotely-generated command signal to vary the attenuation in steps of 1.5 dB through a range of 88 dB. The 1.5 dB steps are controlled by a 4-bit code signal responsive to two bits of the command signal. The 4-bit code signal is directed to four successive bit input terminals of the converter. Which four DAC input terminals are selected is controlled by a shifting matrix which shifts the four bits along the DAC input terminals to a position determined by the other four bits of the command signal.