Patent ID: 7612617
Filing Date: 2009-11-03
Classification: H03C

Abstract:
1. A method for measuring gain of a voltage-controlled oscillator (VCO), comprising: applying a first control signal to a phase-locked loop (PLL); allowing the PLL to settle; recording a first voltage at the input to the VCO in the PLL; applying a second control signal different from the first control signal to the PLL; adjusting the feedback path to compensate for an expected change in the voltage at the input to the VCO; recording a second voltage at the input to the VCO; determining if time is available to compare the measured change in voltage with a threshold value, wherein when time is unavailable proceeding to calculate the gain of the VCO and terminating the method, otherwise when time is available; determining whether a difference between the second voltage and the first voltage at the input to the VCO is within a specified tolerance; when the difference between the second voltage and the first voltage is not within a specified tolerance, further adjusting the feedback path in response to the difference; repeating the recording, determining and further adjusting steps until the difference between the second voltage and the first voltage at the input to the VCO is within the specified tolerance; and calculating the gain of the VCO.