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:
Oct. 11, 2011
Filed:
Oct. 12, 2009
Wilson Wong, San Francisco, CA (US);
Allen Chan, San Jose, CA (US);
Simardeep Maangat, Sunnyvale, CA (US);
Sergey Shumarayev, Los Altos Hills, CA (US);
Wilson Wong, San Francisco, CA (US);
Allen Chan, San Jose, CA (US);
Simardeep Maangat, Sunnyvale, CA (US);
Sergey Shumarayev, Los Altos Hills, CA (US);
Altera Corporation, San Jose, CA (US);
Abstract
An oscillator circuit includes differential variable delay circuits coupled together to form a ring oscillator. Each of the differential variable delay circuits has first and second inputs and first, second, third, and fourth transistors. A constant supply voltage is provided to sources of the first and the second transistors in each of the differential variable delay circuits. A variable supply voltage is provided to sources of the third and the fourth transistors in each of the differential variable delay circuits. Gates of the first and the third transistors are coupled to the first input. Gates of the second and the fourth transistors are coupled to the second input. The oscillator circuit generates a periodic output signal having a frequency that varies based on changes in the variable supply voltage.