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. 04, 1997
Filed:
Mar. 13, 1995
Zhong-Xuan Zhang, Fremont, CA (US);
Cirrus Logic, Inc., Fremont, CA (US);
Abstract
A differential amplifier or delay cell for use in a voltage controlled oscillator comprises a pair of clipper transistors coupled across the output nodes of the amplifier for limiting the voltage swing of the output to a transistor threshold and improving the frequency response of the amplifier. A cross-coupled pair of transistors are included to provide a hysteresis response further improving the noise immunity of the amplifier. A variable control voltage is converted to a current and used to control the frequency of the output signal. An oscillator is formed from three stages, cascaded together, each stage comprising the improved differential amplifier and controlled by a differential reference signal.