Patent ID: 6137375
Filing Date: 2000-10-24
Classification: H03B,H03H,H03L

Abstract:
A loss control loop circuit for controlling the amplitude of the output voltage of a voltage-controlled oscillator (VCO), said VCO output voltage being controlled by a VCO control voltage, said circuit comprising:an envelope detector coupled to receive said VCO output voltage and providing a VCO output envelope voltage;an amplitude regulator coupled to receive said VCO output envelope voltage and a reference voltage, said amplitude regulator providing a sourcing current if said VCO output envelope voltage is less than said reference voltage, and drawing a sinking current if said VCO output envelope voltage is greater than said reference voltage;a current-mode circuit coupled to receive said VCO output envelope voltage and providing a control current;a low-pass filter having high DC gain for integrating said control current and said sourcing or sinking current from said amplitude regulator to provide said VCO control voltage to the VCO; andmeans for providing said VCO control voltage to the VCO.