Voltage controlled oscillator having digitally controlled phase adjustment and method therefor

A voltage controlled oscillator having digitally controlled phase adjustment comprising:

• a first inverting stage for receiving a signal at an input and providing a first inversion of the signal and at an output thereof;
• a second inverting stage for receiving the first inversion of the signal at an input and providing a second inversion of the signal at an output thereof;
• circuitry for coupling the output of the second inverting stage to the input of the first inverting stage;
• and
• phase adjusting circuitry coupled to the output of the first inverting stage, the phase adjusting circuitry comprising:
• a plurality of transistors, each with multiple control electrodes, each of the plurality of transistors being coupled between a supply voltage terminal and the output of the first inverting stage, each of the plurality of multiple control electrode transistors having a first control electrode coupled to a same control signal, a first portion of the plurality of multiple control electrode transistors having a second control electrode coupled to a respective one of a first plurality of digital control signals which make the first portion of the plurality of multiple control electrode transistors conductive unless selectively made non-conductive, a second portion of the plurality of multiple control electrode transistors having a second control electrode coupled to a respective one of a second plurality of digital control signals which make the second portion of the plurality of multiple gate transistors be non-conductive unless selectively made conductive, the first plurality and the second plurality of digital control signals adjusting phase of the signal.

A method of controlling an oscillator comprising:

• providing a bias current or a bias voltage;
• coupling a plurality of inverting stages to the bias current or bias voltage, each of the plurality of inverting stages inverting a signal to provide oscillation;
• and
• phase adjusting the signal by coupling a plurality of transistors with multiple control electrodes to an output of at least one of the plurality of inverting stages, each of the plurality of multiple control electrode transistors having a first control electrode coupled to an input of the at least one of the plurality of inverting stages, a first portion of the plurality of multiple control electrode transistors having a second control electrode coupled to a respective one of a first plurality of digital control signals which makes the first portion of the plurality of multiple control electrode transistors conductive unless selectively made non-conductive, a second portion of the plurality of multiple control electrode transistors having a second control electrode coupled to a respective one of a second plurality of digital control signals which makes the second portion of the plurality of multiple control electrode transistors be non-conductive unless selectively made conductive, the first plurality and the second plurality of digital control signals adjusting phase of the signal.