Patent ID: 6043718
Filing Date: 2000-03-28
Classification: H03K

Abstract:
A signal-controlled oscillator system, comprising:a plurality of time-delay stages that are serially connected in a closed feedback ring, wherein each of said stages includes:a) an amplifier that includes a differential pair of transistors having a differential input and a differential output;b) first and second capacitors;c) signal-controlled impedance elements comprising first and second coupling transistors that each couples a respective one of said capacitors to a different side of said differential output; andd) first and second fixed-bias load transistors that are each coupled to a different side of said differential output;the frequency of said oscillator thereby being a function of a control signal applied to the impedance elements of said stages; anda voltage reference connected to bias said first and second load transistors, said voltage reference including:e) a V.sub.t referenced source that generates a source voltage and a feed-forward current that has a first response to chances in said source voltage;f) a sensor which generates a feedback current that has a second response to said changes that substantially offsets said first response; andg) a summer that sums said feed-forward current and said feedback current into a sum current and generates a reference voltage that is responsive to said sum current;changes in said feed-forward current thus being corrected by changes in said feedback current so that said sum current and said reference voltage are substantially constant.