Frequency to digital converter

A frequency to digital converter for estimating the frequency of an input signal comprising a plurality of pulses and characterized by an input signal frequency, each of the pulses having a corresponding pulse width, the converter comprising:

• an oscillator circuit for generating a count signal comprising a plurality of pulses and characterized by an oscillator frequency that is greater than the input signal frequency, the oscillator circuit configured to begin oscillating upon a change in value of the input signal;
• a counter with an input and an output, the input of the counter coupled to the oscillator circuit such that the counter counts pulses of the count signal, thereby generating a count value;
• and
• a decoder with an input and an output, the input of the decoder coupled to the output of the counter, the decoder configured to estimate the frequency of input signal based upon the count value,
• wherein the oscillator frequency is determined solely by semiconductor based circuit elements.

A frequency to digital converter for estimating the frequency of an input signal comprising a plurality of pulses and characterized by a input signal frequency, each of the pulses having a corresponding pulse width, the converter comprising:

• an oscillator circuit for generating a count signal comprising a plurality of pulses and characterized by an oscillator frequency that is greater than the input signal frequency, wherein the oscillator circuit is configured such that it does not oscillate for at least a portion of a period of the input signal;
• a counter with an input and an output, the input of the counter coupled to the oscillator circuit such that the counter counts pulses of the count signal, thereby generating a count value;
• and
• a decoder with an input and an output, the input of the decoder coupled to the output of the counter, the decoder configured to estimate the frequency of the input signal based upon the count value.