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:
Nov. 19, 1996
Filed:
Jun. 26, 1995
Arnold M Frisch, Portland, OR (US);
Thomas A Almy, Tualatin, OR (US);
Tektronix, Inc., Wilsonville, OR (US);
Abstract
A variable reference voltage generator provides variable voltage rails for a delay element in order to control the amount of delay of an electrical signal through the delay element. A control signal, such as an error signal from a phase locked loop, is input to a pair of operational amplifiers, one configured as a unity gain buffer and the other configured as a positive gain feedback amplifier. The one amplifier is coupled to one input of a modified Magee inverter circuit and the other amplifier is coupled to the other input of the modified Magee inverter circuit. The variable voltage rails are taken from the output buffers of the modified Magee inverter circuit. To provide a range of voltages for the variable voltage rails that approaches the power supply voltages, the two outer transistors of the modified Magee inverter circuit are converted to voltage sources so that the control signal is added to the positive power supply voltage and subtracted from the negative power supply voltage.