Controller for a power converter and a method of controlling a switch thereof
View Patent ↗A controller for, related method of controlling a switch of, a power converter and a power converter employing the same. The controller is employable with a power converter including a switch of a power train configured to conduct for a duty cycle and provide a regulated output characteristic at an output thereof. In one embodiment, the controller includes a sparse analog-to-digital converter configured to determine a difference between the output characteristic and a desired characteristic and provide an error signal representing the difference in discrete steps. A magnitude of the discrete steps is small when the difference is small and the magnitude of the discrete steps is larger when the difference is larger. The controller also includes a duty cycle processor configured to provide a digital duty cycle signal to control the duty cycle of the switch as a function of the error signal.
1. A controller for use with a power train of a power converter including a switch configured to conduct for a duty cycle and provide a regulated output characteristic at an output thereof, comprising:
a sparse analog-to-digital converter configured to determine a difference between said output characteristic and a desired characteristic and provide an error signal representing said difference in discrete steps, a magnitude of said discrete steps being small when said difference is small and a magnitude of said discrete steps being larger when said difference is larger; and
a duty cycle processor configured to provide a digital duty cycle signal to control said duty cycle of said switch as a function of said error signal.
2. The controller as recited in claim 1 wherein said sparse analog-to-digital converter comprises a resistor divider configured to provide at least one scaled representation of said desired characteristic.
3. The controller as recited in claim 1 wherein said sparse analog-to-digital converter further comprises a comparator bank configured to provide said error signal.
4. The controller as recited in claim 1 wherein said duty cycle processor comprises a duty cycle encoder configured to provide a modification signal representing a change to said duty cycle as a function of said error signal.
5. The controller as recited in claim 4 wherein said duty cycle processor further comprises a duty cycle conditioning circuit configured to provide a conditioned modification signal as a function of said modification signal from said duty cycle encoder.
6. The controller as recited in claim 5 wherein said duty cycle processor further comprises a full adder and a duty cycle register configured to provide said digital duty cycle signal as a function of said conditioned modification signal from said duty cycle conditioning circuit.
7. The controller as recited in claim 1 further comprising a digital-to-analog converter configured to transform said desired characteristic from a digital format to an analog format employable by said sparse analog-to-digital converter.
8. The controller as recited in claim 1 further comprising a modulator configured to convert said digital duty cycle signal into a signal to control said duty cycle of said switch of said power converter.
9. A method of controlling a duty cycle of a switch to provide a regulated output characteristic at an output of a power converter, comprising:
determining a difference between said output characteristic and a desired characteristic and providing an error signal representing said difference in discrete steps, a magnitude of said discrete steps being small when said difference is small and a magnitude of said discrete steps being larger when said difference is larger; and
providing a digital duty cycle signal to control said duty cycle of said switch as a function of said error signal.
10. The method as recited in claim 9 wherein said determining comprises providing at least one scaled representation of said desired characteristic and providing said error signal therefrom.
11. The method as recited in claim 9 wherein said providing comprises providing a modification signal representing a change to said duty cycle as a function of said error signal.
12. The method as recited in claim 11 wherein said providing further comprises providing a conditioned modification signal as a function of said modification signal.
13. The method as recited in claim 12 wherein said providing further comprises modifying and storing contents of a duty cycle register to provide said digital duty cycle signal as a function of said conditioned modification signal.
14. The method as recited in claim 9 further comprising transforming said desired characteristic from a digital format to an analog format employable by said act of determining.
15. The method as recited in claim 9 further comprising converting said digital duty cycle signal into a drive signal for said switch of said power converter.
16. A power converter, comprising:
a power train including a switch configured to conduct for a duty cycle and provide a regulated output characteristic at an output of said power converter; and
a controller, including:
a sparse analog-to-digital converter configured to determine a difference between said output characteristic and a desired characteristic and provide an error signal representing said difference in discrete steps, a magnitude of said discrete steps being small when said difference is small and a magnitude of said discrete steps being larger when said difference is larger, and
a duty cycle processor configured to provide a digital duty cycle signal to control said duty cycle of said switch as a function of said error signal.
17. The power converter as recited in claim 16 wherein said sparse analog-to-digital converter comprises:
a resistor divider configured to provide at least one scaled representation of said desired characteristic, and
a comparator bank configured to provide said error signal.
18. The power converter as recited in claim 16 wherein said duty cycle processor comprises:
a duty cycle encoder configured to provide a modification signal representing a change to said duty cycle as a function of said error signal,
a duty cycle conditioning circuit configured to provide a conditioned modification signal as a function of said modification signal from said duty cycle encoder, and
a full adder and a duty cycle register configured to provide said digital duty cycle signal as a function of said conditioned modification signal from said duty cycle conditioning circuit.
19. The power converter as recited in claim 16 wherein said controller further comprises a digital-to-analog converter configured to transform said desired characteristic from a digital format to an analog format employable by said sparse analog-to-digital converter.
20. The power converter as recited in claim 16 wherein said controller further comprises a modulator configured to convert said digital duty cycle signal into a signal employable by a driver to provide a drive signal to said switch of said power converter.