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:
Jul. 19, 1994
Filed:
Oct. 16, 1992
Timothy D Davis, Arlington, TX (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
A low-power crystal oscillator circuit is disclosed that includes an amplifier section having a switchable compensation network. In one embodiment, the oscillator circuit incorporates inverter amplifiers to generate a square-wave output signal that can be used, for example, as a clock signal to drive microprocessors and other digital circuitry. The invention takes advantage of the observation that, if the uncompensated bandwidth is not too excessive, compensation is only needed at start-up to ensure oscillation at the desired crystal frequency. Once the desired oscillation is attained, most of the oscillation cycle occurs during the non-linear regions of the amplifier. These non-linear regions are characterized by low gain, thus suppressing any spurious oscillation. The compensation network is removed after start-up to reduce power consumption.