Patent ID: 8299777
Filing Date: 2012-10-30
Classification: G01R

Abstract:
1. A method for determining a parasitic capacitance of an oscillator circuit, the method comprising: identifying a total load capacitance for an oscillator circuit; measuring a first frequency of an oscillator crystal separate from the oscillator circuit at the total load capacitance; measuring a second frequency of the oscillator crystal coupled to the oscillator circuit, the oscillator circuit including at least one first capacitor having a first capacitor value; measuring a third frequency of the oscillator crystal coupled to the oscillator circuit, the oscillator circuit including at least one second capacitor having a second capacitor value that is different than the first value; determining a third capacitor value, for use in the oscillator circuit, to cause the oscillator circuit to produce the first frequency, the third capacitor value determined based on the first frequency, the second frequency, the third frequency and the first and second capacitor values; and determining a parasitic capacitance of the oscillator circuit based on the third capacitor value and the total load capacitance.