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:
Feb. 21, 1995
Filed:
Dec. 02, 1993
Adrian B Early, Buda, TX (US);
Jeffrey D Ganger, Austin, TX (US);
Motorola Inc., Schaumburg, IL (US);
Abstract
A fully differential switched-capacitor biquad low pass filter (40) includes a first stage (54), second stage (56), common-mode circuits (55, 72), and feedback transmission gates (73, 74). The first stage (54) includes a first operational amplifier (47), and the second stage (56) includes a second operational amplifier (69). Glitches, or transients, which are caused by the operational amplifiers (47, 69) operating in slew rate limit mode, are prevented from affecting the differential output signals of the filter (40) when the filter (40) is operating with a continuous time output. This is accomplished by preventing the operational amplifiers (47, 69) from operating in slew rate limit mode, or by adjusting the clock signals such that the output of the filter (40) is not coupled to an operational amplifier (47, 69) that is recovering from operation in slew rate limit mode.