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:
Aug. 07, 2001
Filed:
Aug. 12, 1997
Lapoe E. Lynn, Somerville, MA (US);
Paul F. Ferguson, Jr., North Andover, MA (US);
Hae-Seung Lee, Bedford, MA (US);
Analog Devices, Inc., Norwood, MA (US);
Abstract
A digital-to-analog converter (DAC) including an array of switched input capacitors which store samples of charge proportional to a digital input signal, and an analog output circuit which integrates the samples of charge to generate an output analog signal that is proportional to said digital input signal. The capacitors store a binary representation of the digital input signal. The output circuit includes a zeroth order sample-and-hold circuit having first and second stages with respective first and second operational amplifiers. The first and second stages are cascaded together during a sample phase so that the analog output signal is stored in a capacitor in a feedback path between the output of the second stage and the input of the first stage, and are disconnected from one another during a hold phase so that the first stage is auto-zeroed and the second stage holds the analog output signal as a continuous time output.