Patent ID: 7956695
Filing Date: 2011-06-07
Classification: H03K

Abstract:
1. A calibration method for use with an oscillator, said oscillator being part of a loop circuit and providing an output signal in a range of frequencies in response to an input signal based on an output of said loop circuit, said range of frequencies being divided into a plurality of subranges, said oscillator comprising a shift register having a plurality of locations corresponding to said plurality of subranges, each location of said shift register starting at a first end up to a position corresponding to said one of said subranges being loaded with a value indicating “select” and each location beyond said position corresponding to said one of said subranges being loaded with a value indicating “deselect”; wherein: said calibration method selects one of said subranges; and said calibration method comprises: initializing said oscillator in a default subrange; comparing said input signal to an upper threshold and when said input signal exceeds said upper threshold, adjusting said oscillator to a lower one of said subranges by shifting said value indicating “deselect” into said shift register; comparing said input signal to a lower threshold and when said input signal is less than said lower threshold, adjusting said oscillator to a higher one of said subranges by shifting said value indicating “select” into said shift register; and repeating said comparing to an upper threshold and adjusting, and repeating said comparing to a lower threshold and adjusting, until said input signal is at most equal to said upper threshold and at least equal to said lower threshold.