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:
Sep. 27, 2005
Filed:
Jun. 06, 2002
Patrick Peter Siniscalchi, Sachse, TX (US);
Patrick Peter Siniscalchi, Sachse, TX (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A voltage controlled oscillator () includes a voltage to current portion () that is inversely proportional to the semiconductor processing in order to compensate for variations both in the low-frequency and high-frequency portions of the VCO gain response. To compensate for low-frequency variations, a portion of the control current (I), non-compensated control current I(), is subtracted from a reference current I() and the result, a low-frequency compensating control current, I(), is added to the non-compensated control current I(). To compensate for high frequency variations, a number of differential transistor pairs () are provided that have tail currents that are inversely proportional to the processing. One input () to all the differential pairs is connected to the VCO's control voltage while the other inputs () are connected to successively increasing voltages in the control voltage range. One output, I(), of all the differential pairs is summed with the non-compensated control current I() while the other output of each differential pair is connected to the power supply. By adjusting the amount of non-compensated control current I() provided to transistor Musing the low frequency gain compensation circuitand high frequency gain compensation circuit, VCO () provides for a process-insensitive, substantially constant gain VCO.