DIGITAL DOUBLE-LOOP OUTPUT VOLTAGE REGULATION
First Claim
1. A voltage regulator comprising:
- at least one power switch adapted to convey power between respective input and output terminals of said voltage regulator; and
a digital controller adapted to control operation of said at least one power switch responsive to an output of said voltage regulator, said digital controller comprising;
a first digital control loop including a first analog-to-digital converter providing a first digital measurement of said voltage regulator output, a digital filter providing a digital control output based on a first digital error signal and a second digital error signal, and a digital pulse width modulator providing a control signal to said at least one power switch based on said digital control output, the first digital error signal comprising a difference between the first digital measurement and a digital reference value, the second digital error signal comprising a sum of the first digital error signal and a time varying portion of the digital reference value; and
a second digital control loop including a second analog-to-digital converter providing a second digital measurement of said voltage regulator output, said second analog-to-digital converter having greater resolution than said first analog-to-digital converter, said second digital control loop providing the digital reference value based on a desired output voltage setpoint, said second digital control loop providing said time varying portion of the digital reference value based on a difference between said second digital measurement and said output voltage setpoint.
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Accused Products
Abstract
A switched mode voltage regulator has a digital control system that includes dual digital control loops. The voltage regulator comprises at least one power switch adapted to convey power between respective input and output terminals of the voltage regulator and a digital controller adapted to control operation of the power switches responsive to an output of the voltage regulator. The digital controller further comprises dual digital control loops in which a first control loop provides high speed with lower regulation accuracy and a second control loop has high accuracy with lower speed. Thus, the digital control system provides the advantages of both high speed and high regulation accuracy.
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Citations
26 Claims
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1. A voltage regulator comprising:
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at least one power switch adapted to convey power between respective input and output terminals of said voltage regulator; and
a digital controller adapted to control operation of said at least one power switch responsive to an output of said voltage regulator, said digital controller comprising;
a first digital control loop including a first analog-to-digital converter providing a first digital measurement of said voltage regulator output, a digital filter providing a digital control output based on a first digital error signal and a second digital error signal, and a digital pulse width modulator providing a control signal to said at least one power switch based on said digital control output, the first digital error signal comprising a difference between the first digital measurement and a digital reference value, the second digital error signal comprising a sum of the first digital error signal and a time varying portion of the digital reference value; and
a second digital control loop including a second analog-to-digital converter providing a second digital measurement of said voltage regulator output, said second analog-to-digital converter having greater resolution than said first analog-to-digital converter, said second digital control loop providing the digital reference value based on a desired output voltage setpoint, said second digital control loop providing said time varying portion of the digital reference value based on a difference between said second digital measurement and said output voltage setpoint. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method of controlling a voltage regulator comprising at least one power switch adapted to convey power between input and output terminals of said voltage regulator, said method comprising:
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receiving first and second output measurements of said voltage regulator;
sampling said first output measurement to provide a first digital error signal representing a difference between said output measurement and a reference value;
sampling said second output measurement to provide a time varying portion of a difference between said second output measurement and a reference value;
combining the time varying portion with the first digital error signal to provide a second digital error signal;
filtering said first and second digital error signals to provide a digital control output; and
providing a control signal to said at least one power switch, said control signal having a pulse width corresponding to said digital control output;
wherein, said first sampling step is performed at substantially higher speed and lower resolution than said second sampling step. - View Dependent Claims (12, 13, 14, 15, 16)
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17. A digital controller for a voltage regulator having at least one power switch adapted to convey power between respective input and output terminals of said voltage regulator, said digital controller being adapted to control operation of said at least one power switch responsive to an output of said voltage regulator, said digital controller comprising:
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a first digital control loop including a first analog-to-digital converter providing a first digital measurement of said voltage regulator output, a digital filter providing a digital control output based on a first digital error signal and a second digital error signal, and a digital pulse width modulator providing a control signal to said at least one power switch based on said digital control output, the first digital error signal comprising a difference between the first digital measurement and a digital reference value, the second digital error signal comprising a sum of the first digital error signal and a time varying portion of the digital reference value; and
a second digital control loop including a second analog-to-digital converter providing a second digital measurement of said voltage regulator output, said second analog-to-digital converter having greater resolution than said first analog-to-digital converter, said second digital control loop providing the digital reference value based on a desired output voltage setpoint, said second digital control loop providing said time varying portion of the digital reference value based on a difference between said second digital measurement and said output voltage setpoint. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26)
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Specification