Adjustable voltage regulator calibration circuit
AssigneeAltera Corporation
InventorsWilson Wong, Allen Chan
Life of this patent
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Abstract
An integrated circuit is presented. The integrated circuit includes a selection circuit that selects a reference voltage and an output voltage associated with a number of adjustable voltage regulators connected to the selection circuit. The integrated circuit also has an analog to digital converter, which converts the selected output voltage and the reference voltage to a digital representation. An analog state machine of the integrated circuit receives the digital representation from the analog to digital converter and compares the selected output voltage with the reference voltage.
Claims20
An integrated circuit comprising:
- a plurality of adjustable voltage regulators;
- a selection circuit operable to select one of a reference voltage or a voltage of a voltage regulator from the plurality of adjustable voltage regulators to form a selected output voltage, the reference voltage is a power supply voltage of a data path, the voltage regulator is a power supply of a clock path;
- an analog to digital converter operable to convert the selected output voltage to form a digital selected output voltage, wherein said analog to digital converter is further operable to convert the reference voltage to form a digital reference voltage;
- and
- a state machine operable to receive the digital selected output voltage and the digital reference voltage from the analog to digital converter, wherein the state machine is further operable to determine whether the digital selected output voltage, formed with the selection circuit selecting the voltage of the voltage regulator, matches the digital reference voltage and to adjust the voltage regulator that is the power supply of the clock path until a power supply voltage of the clock path is within a predefined range of the power supply voltage of the data path wherein the predefined range is determined by a number of control bits.
A calibration circuit comprising:
- an analog multiplexer having a plurality of input terminals, the plurality of input terminals coupled to a reference voltage and an output voltage associated with an adjustable voltage regulator, the reference voltage is a supply voltage of a data path, the output voltage is a supply voltage of a clock path;
- and
- a state machine having a lookup table for storing a digital value of the reference voltage, wherein the state machine is operable to compare the output voltage to the stored digital reference voltage, and wherein the state machine is operable to adjust the output voltage until the supply voltage of the clock path is within a predefined range of the supply voltage of the data path, based on the comparison by transmitting a control signal to the adjustable voltage regulator, wherein the predefined range is determined by a number of control bits.
A method of dynamically calibrating an output voltage of an adjustable voltage regulator to a reference voltage, the method comprising:
- selecting one of a plurality of analog voltages to form a selected output voltage, wherein each analog voltage of the plurality of analog voltages corresponds to an output voltage of an adjustable voltage regulator, wherein one analog voltage of the plurality of analog voltages is a power supply voltage of a clock path, wherein the selecting is based on a plurality of selection bits;
- comparing a reference voltage with the selected output voltage, the reference voltage is a power supply voltage of a data path;
- and
- adjusting the adjustable voltage regulator corresponding to the analog voltage that is the power supply voltage of the clock path, until the power supply voltage of the clock path is within a predefined range of the power supply voltage of the data path wherein the predefined range is determined by a number of control bits.
Dependencies are inferred from the claim text.