Automatic amplitude control for voltage controlled oscillator

A method comprising:

• determining an amplitude of a VCO (voltage controlled oscillator) output signal based on a voltage present at a tail node of the VCO;
• generating a first indication if the amplitude is not within a specified range;
• responsive to generation of the first indication, adjusting the amplitude, wherein adjusting the amplitude comprises adjusting the tail voltage;
• generating a second indication if the amplitude is within the specified range;
• and
• discontinuing adjustment of the amplitude responsive to generation of the second indication.

A computer readable medium comprising a data structure which is operated upon by a program executable on a computer system, the program operating on the data structure to perform a portion of a process to fabricate an integrated circuit including circuitry described by the data structure, the circuitry described in the data structure including:

• voltage controlled oscillator (VCO) configured to generate a VCO output signal;
• a bias control circuit coupled to a tail node of the VCO;
• and
• an amplitude control unit configured to determine an amplitude of the VCO output signal depending upon on a voltage present at the tail node, and wherein the amplitude control unit is configured generate a bias voltage dependent upon a target voltage and the amplitude of the VCO output signal;
• wherein the bias control circuit is configured to adjust the voltage at the tail node depending upon the received bias voltage.