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. 01, 1989
Filed:
Sep. 11, 1987
Daniel P Brown, Elmhurst, IL (US);
Carl M Danielsen, Lake Zurich, IL (US);
Ezzat A Dabbish, Buffalo Grove, IL (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A zener diode random number generator circuit is described which produces a random binary number output having a statistical distribution exhibiting a controlled degree of randomness determined in response to an input control signal. A microprocessor feedback circuit monitors the random number output and produces the input control signal in response to the difference between the degree of randomness of the output signal and that of a pre-determined statistical distribution. The digital feedback automatically adjusts the zener diode biasing point and the limiter threshold such that part-to-part tolerance, component aging, temperature variations, or voltage fluctuations will not adversely affect the randomness of the bit stream output. In the preferred embodiment, the microprocessor tests the ratio of ONES bits to ZERO bits of the random number such that a desired 1:1 ONES/ZERO ratio is approximated.