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:
Jan. 29, 1991
Filed:
Dec. 27, 1989
Thierry Fensch, Grenoble, FR;
SGS-Thomson Microelectronics S.A., Gentilly, FR;
Abstract
A generator capable of forming an analog signal having a waveform determined from a sequence of digital control words applied at a high frequency, each word representing an increment of the analog signal to be produced at the output. For this type of generator, the accuracy of the increment value is an essential parameter. If several increments having a different value are generated as a function of the control word, their ratio has to be very accurate. The diclosed circuit is of the switched-capacitor type; it comprises several input capacitors (C1, C2, C3) that are theoretically identical. In order to take into account the dispersion due to manufacturing, a procedure for choosing the best input capacitor is previously established for obtaining a precise ratio between the increments (+V, +3V, -V, -3V) that can be supplied at the output. This procedure consists in comparing capacitors by pairs to sequence them and select the median capacitor. Comparison is carried out by using the main amplifier of the switched-capacitor circuit.