Methods and apparatus for compensating a variable oscillator for process, voltage, and temperature variations using a replica oscillator

A circuit comprising:

• a) a replica oscillator;
• b) a counter configured to count pulses of said replica oscillator and to produce a count signal;
• and
• c) a compensation circuit configured to provide an adjustment signal to a variable oscillator in accordance with said count signal;
• wherein said replica oscillator is configured to start in response to a first edge of a reference clock signal, and to stop in response to a second edge of said reference clock signal.

A circuit comprising:

• a) a replica oscillator:
• b) a counter configured to count pulses of said replica oscillator and to produce a count signal;
• c) a compensation circuit configured to provide an adjustment signal to a variable oscillator in accordance with said count signal;
• and
• d) a control circuit configured to produce one or more control signals in response to a reference clock signal;
• wherein said replica oscillator is configured to start and stop in response to at least one of said control signals.

A method of compensating a variable oscillator for process and/or operational variations, comprising the steps of:

• a) counting the number of pulses of a replica oscillator signal and generating a count signal;
• b) providing an adjustment signal to said variable oscillator in accordance with said number of pulses;
• c) producing one or more control signals in response to a reference clock signal, and producing said replica oscillator signal in response to at least one of said control signals;
• and
• d) updating said adjustment signal in response to at least one of said control signals.

A method of compensating a variable oscillator for process and/or operational variations, comprising the steps of:

• a) counting the number of pulses of a replica oscillator signal and generating a count signal;
• b) providing an adjustment signal to said variable oscillator in accordance with said number of pulses;
• c) producing one or more control signals in response to a reference clock signal, and producing said replica oscillator signal in response to at least one of said control signals;
• and
• d) resetting said count signal in response to said at least one of control signals.