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. 15, 1999
Filed:
Oct. 29, 1996
Nicholas Mihailovits, Sale, GB;
Trevor P Beatson, Manchester, GB;
Mitel Semiconductor Limited, , GB;
Abstract
Active filter circuit 1 consists of five filter stages 70-74 cascoded between a voltage supply and ground potential. The circuit has two major current paths, the first through the collector-emitter paths at transistors 31, 33, 35, 37 and 39, the second through transistors 32, 34, 36, 38 and 40. Each major current path is driven by a current source 61, 62. In operation, a differential input signal is applied to the base electrodes of transistors 31, 32 and a differential output signal is taken from the emitters of transistors 39, 40. The transistors 33, 34 of stage 71 have their collector and base electrodes cross-coupled. Transistors 35-40 of stages 72-74 are connected in the same manner. In another embodiment (FIG. 3, not shown) a cut-off frequency is varied under control of controllable current sources.