Digital Adaptive Voltage Supply

A method for regulating voltage supplied to a circuit comprising the steps of:

• measuring temperature within the circuit to provide a measured temperature,
• using the measured temperature to access previously stored data indicating a predicted frequency value,
• measuring a first frequency within the circuit to provide a measured frequency value,
• combining the predicted frequency with the measured frequency value to provide a scaling value, and
• adjusting voltage supplied to the circuit in response to the scaling value.

A method for regulating voltage supplied to a circuit comprising the steps of:

• receiving a first voltage from a thermal diode on the circuit;
• addressing a table of digital temperature representations by incrementing an address every cycle of a circuit clock,
• converting the addressed data to a second voltage representing an addressed temperature,
• comparing the first voltage with the second voltage, and
• providing a temperature value when both the first and second voltages are equal,
• addressing a predetermined frequency table with the temperature value to obtain an accessed predetermined frequency value,
• providing a frequency value from a ring oscillator,
• combining the frequency value and the accessed predetermined frequency value to provide a voltage scaling value, and
• adjusting voltage supplied to the circuit in response to the scaling value.

A method for regulating voltage supplied by a voltage source to a circuit comprising the steps of:

• receiving a first frequency value from a first ring oscillator,
• receiving a second frequency value from a second ring oscillator,
• combining the first and second frequency values to form a voltage scaling value, and
• providing the voltage scaling value to the circuit voltage source.

An electronic system comprising:

• a thermal diode,
• an addressing circuit connected to a system clock,
• a digital temperature table connected to the addressing circuit,
• a comparator connected to the digital temperature table and to the thermal diode,
• a predicted frequency response table connected to the output of the comparator and providing a predicted frequency response value,
• a first frequency circuit providing a first frequency value,
• a second frequency circuit providing a second frequency value,
• a first differencing circuit connected to the frequency response table and the first frequency circuit providing a first difference value of the first frequency value and the predicted frequency response value,
• a second differencing circuit connected to the first frequency circuit and the second frequency circuit and providing a second difference value of the first frequency value and the second frequency value,
• a voltage scaling signal circuit connected to the first and second differencing circuits and providing a voltage scaling signal from a combination of the first and second difference values, and
• a voltage supply providing power to the electronic system in response to a voltage scaling signal received from the voltage scaling signal circuit.