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. 10, 1993
Filed:
Apr. 26, 1990
Geert DeVeirman, Irvine, CA (US);
Silicon Systems, Inc., Tustin, CA (US);
Abstract
A filter circuit with improved performance characteristics. A biquadratic transconductance-C filter includes a differentiator in the feed forward path of the input signal to compensate for the non-ideal operation of the transconductance elements and to simplify the performance requirements of a variable gain amplifier also in the feed forward path. The variable gain amplifier and feed forward technique are used to create two programmable magnitude, opposite sign zeros on the real axis, whose effect on the incoming data signal results in variable pulse slimming. The addition of a differentiator in the feed forward path eliminates the effect of the output admittance of the transconductance elements on the filter's group delay. The differentiator acts as a first order, high pass filter. The frequency of the differentiator is controlled so that the input signal is attenuated before it is provided to the variable gain amplifier. This reduces the dynamic range requirements of the variable gain amplifier without affecting group delay requirements.