Switch-mode converter operating in a hybrid discontinuous conduction mode (DCM)/continuous conduction mode (CCM) that uses double or more pulses in a switching period

• US 8,125,805 B1
• Filed: 05/01/2008
• Issued: 02/28/2012
• Est. Priority Date: 05/02/2007
• Status: Active Grant

• Current Assignee: Cirrus Logic Incorporated
• Original Assignee: Cirrus Logic Incorporated
• Inventors: Melanson, John Laurence
• Primary Examiner(s): Behm, Harry
• Application Number:
  US12/113,536
• Time in Patent Office: 1,398 Days
• Field of Search: 363/89, 363/41, 323/222, 323/207
• US Class Current: 363/89
• CPC Class Codes: H02M 1/4225 using a non-isolated boost converter
• CPC Class Codes: H03M 3/476 Non-linear conversion systems
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
• CPC Class Codes: Y02P 80/10 Efficient use of energy, e.g. using compressed air or pressurized fluid as energy carrier

Abstract

A switching converter controller and method for controlling a switch-mode converter in a hybrid discontinuous conduction mode (DCM)/continuous conduction mode (CCM) mode are disclosed. The hybrid mode involves using double (two) or more switching pulses in a switching period of a control signal for controlling the switch-mode converter. The switching period is defined by a switch on-time duration, a switch off-time duration, and an N number of switching pulses. N is an integer greater than one. An inductor current through the inductor of the switch-mode converter is zero before an initial switching pulse, is zero after a last switching pulse, and is non-zero for all other times within the switching period. The switch-mode converter controller can be used as a power factor correction controller for a power factor corrector. The switch-mode converter controller can be implemented on a single integrated circuit.

Claims

1. A switching converter controller for controlling a switch-mode converter which has a switch and an inductor coupled to the switch wherein the switch-mode converter receives an input voltage and provides an output voltage, comprising:

a finite state machine configured to operate the switch-mode converter in a hybrid discontinuous conduction mode (DCM)/continuous conduction mode (CCM) mode;

wherein the finite state machine defines a switching period for a control signal for controlling the switch based on an on-time duration of the switch, an off-time duration of the switch, and an N number of switching pulses defined within the switching period wherein N is an integer greater than one and wherein an inductor current through the inductor is zero before an initial switching pulse of the N number of switching pulses, is zero after a last switching pulse of the N number of switching pulses, and is non-zero for all other times within the switching period; and

wherein the N number of switching pulses is two switching pulses and the hybrid DCM/CCM mode is a hybrid DCM/CCM double-pulse mode.

2. The switching converter controller of claim 1 wherein the switching converter controller is a power factor correction (PFC) controller for controlling the switch-mode converter that is a switch-mode boost converter.

3. A method for controlling a switch-mode converter which has a switch and an inductor coupled to the switch wherein the switch-mode converter receives an input voltage and provides an output voltage, comprising:

configuring to operate the switch-mode converter in a hybrid discontinuous conduction mode (DCM)/continuous conduction mode (CCM) mode;

defining a switching period for a control signal for controlling the switch based on an on-time duration of the switch, an off-time duration of the switch, and an N number of switching pulses defined within the switching period wherein N is an integer greater than one and wherein an inductor current through the inductor is zero before an initial switching pulse of the N number of switching pulses, is zero after a last switching pulse of the N number of switching pulses, and is non-zero for all other times within the switching period; and

defining a fraction, that is greater than zero and less than one, based on a ratio of a width of a subsequent switching pulse after the initial switching pulse and before the last switching pulse to a width of the initial switching pulse; and

for the subsequent switching pulse, turning on the switch for a fraction of the on-time duration and turning off the switch for the fraction of the off-time duration.

4. The method of claim 3 wherein the N number of switching pulses is two switching pulses and further comprising:

configuring to operate the switch-mode converter in a hybrid DCM/CCM double-pulse mode.

5. The method of claim 3 wherein the N number of switching pulses is three switching pulses and further comprising:

configuring to operate the switch-mode converter in a hybrid DCM/CCM triple-pulse mode.

6. The method of claim 3 wherein defining the fraction further comprises:

selecting an optimal value for the fraction in a range between 0.25 and 0.50.

7. The method of claim 3 further comprising:

controlling the switch-mode converter that is a switch-mode boost converter which is used in a power factor corrector.

8. An integrated circuit which incorporates a switch-mode converter controller for controlling a switch-mode converter which has a switch and an inductor coupled to the switch wherein the switch-mode converter receives an input voltage and provides an output voltage, and wherein the switch-mode converter controller includes a finite state machine, the integrated circuit configured to:

operate the switch-mode converter in a hybrid discontinuous conduction mode (DCM)/continuous conduction mode (CCM) mode;

define a switching period for a control signal for controlling the switch based on an on-time duration of the switch, an off-time duration of the switch, and an N number of switching pulses defined within the switching period wherein N is an integer greater than one and wherein an inductor current through the inductor is zero before an initial switching pulse of the N number of switching pulses, is zero after a last switching pulse of the N number of switching pulses, and is non-zero for all other times within the switching period;

set the N number of switching pulses to two switching pulses; and

operate the switch-mode converter in a hybrid DCM/CCM double-pulse mode.

9. The integrated circuit of claim 8 further configured to:

control the switch-mode converter that is a switch-mode boost converter which is used in a power factor corrector.

10. A power factor corrector (PFC), comprising:

a switch-mode boost stage having a switch and an inductor coupled to the switch wherein the switch-mode boost stage receives a rectified line input voltage and provides a link output voltage;

a target current generator for receiving the link output voltage and for generating a target current proportionate to the rectified line input voltage; and

a finite state machine configured to operate the switch-mode boost stage in a hybrid discontinuous conduction mode (DCM)/continuous conduction mode (CCM) mode and;

wherein the finite state machine defines a switching period for a control signal for controlling the switch based on an on-time duration of the switch, an off-time duration of the switch, an N number of switching pulses defined within the switching period wherein N is an integer greater than one and wherein an inductor current through the inductor is zero before an initial switching pulse of the N number of switching pulses, is zero after a last switching pulse of the N number of switching pulses, and is non-zero for all other times within the switching period; and

wherein the N number of switching pulses is two switching pulses and the hybrid DCM/CCM mode is a hybrid DCM/CCM double-pulse mode.

11. A switching converter controller for controlling a switch-mode converter which has a switch and an inductor coupled to the switch wherein the switch-mode converter receives an input voltage and provides an output voltage, comprising:

a finite state machine configured to operate the switch-mode converter in a hybrid discontinuous conduction mode (DCM)/continuous conduction mode (CCM) mode;

wherein the finite state machine defines a switching period for a control signal for controlling the switch based on an on-time duration of the switch, an off-time duration of the switch, and an N number of switching pulses defined within the switching period wherein N is an integer greater than one and wherein an inductor current through the inductor is zero before an initial switching pulse of the N number of switching pulses, is zero after a last switching pulse of the N number of switching pulses, and is non-zero for all other times within the switching period; and

wherein the N number of switching pulses is three switching pulses and the hybrid DCM/CCM mode is a hybrid DCM/CCM triple-pulse mode.

12. The switching converter controller of claim 11 wherein the switching converter controller is a power factor correction (PFC) controller for controlling the switch-mode converter that is a switch-mode boost converter.

13. A switching converter controller for controlling a switch-mode converter which has a switch and an inductor coupled to the switch wherein the switch-mode converter receives an input voltage and provides an output voltage, comprising:

a finite state machine configured to operate the switch-mode converter in a hybrid discontinuous conduction mode (DCM)/continuous conduction mode (CCM) mode;

wherein the finite state machine defines a switching period for a control signal for controlling the switch based on an on-time duration of the switch, an off-time duration of the switch, and an N number of switching pulses defined within the switching period wherein N is an integer greater than one and wherein an inductor current through the inductor is zero before an initial switching pulse of the N number of switching pulses, is zero after a last switching pulse of the N number of switching pulses, and is non-zero for all other times within the switching period; and

wherein for a subsequent switching pulse after the initial switching pulse and before the last switching pulse, the switch is turned on for a fraction of the on-time duration and the switch is turned off for the fraction of the off-time duration, wherein the fraction is greater than zero and less than one and is defined by a ratio of a width of the subsequent switching pulse to a width of the initial switching pulse.

14. The switching converter controller of claim 13 wherein the fraction is selected as an optimal value in a range between 0.25 and 0.50.

15. The switching converter controller of claim 13 wherein the switching converter controller is a power factor correction (PFC) controller for controlling the switch-mode converter that is a switch-mode boost converter.

16. An integrated circuit which incorporates a switch-mode converter controller for controlling a switch-mode converter which has a switch and an inductor coupled to the switch wherein the switch-mode converter receives an input voltage and provides an output voltage, and wherein the switch-mode converter controller includes a finite state machine, the integrated circuit configured to:

operate the switch-mode converter in a hybrid discontinuous conduction mode (DCM)/continuous conduction mode (CCM) mode;

define a switching period for a control signal for controlling the switch based on an on-time duration of the switch, an off-time duration of the switch, and an N number of switching pulses defined within the switching period wherein N is an integer greater than one and wherein an inductor current through the inductor is zero before an initial switching pulse of the N number of switching pulses, is zero after a last switching pulse of the N number of switching pulses, and is non-zero for all other times within the switching period;

set the N number of switching pulses to three switching pulses; and

operate the switch-mode converter in a hybrid DCM/CCM triple-pulse mode.

17. The integrated circuit of claim 16 further configured to:

control the switch-mode converter that is a switch-mode boost converter which is used in a power factor corrector.

18. An integrated circuit which incorporates a switch-mode converter controller for controlling a switch-mode converter which has a switch and an inductor coupled to the switch wherein the switch-mode converter receives an input voltage and provides an output voltage, and wherein the switch-mode converter controller includes a finite state machine, the integrated circuit configured to:

operate the switch-mode converter in a hybrid discontinuous conduction mode (DCM)/continuous conduction mode (CCM) mode;

define a switching period for a control signal for controlling the switch based on an on-time duration of the switch, an off-time duration of the switch, and an N number of switching pulses defined within the switching period wherein N is an integer greater than one and wherein an inductor current through the inductor is zero before an initial switching pulse of the N number of switching pulses, is zero after a last switching pulse of the N number of switching pulses, and is non-zero for all other times within the switching period;

define a fraction, that is greater than zero and less than one, based on a ratio of a width of a subsequent switching pulse after the initial switching pulse and before the last switching pulse to a width of the initial switching pulse; and

for the subsequent switching pulse, turn on the switch for a fraction of the on-time duration and turn off the switch for the fraction of the off time duration.

19. The integrated circuit of claim 18 further configured to:

select the fraction as an optimal value in a range between 0.25 and 0.50.

20. The integrated circuit of claim 18 further configured to:

control the switch-mode converter that is a switch-mode boost converter which is used in a power factor corrector.

21. A power factor corrector (PFC), comprising:

a switch-mode boost stage having a switch and an inductor coupled to the switch wherein the switch-mode boost stage receives a rectified line input voltage and provides a link output voltage;

a target current generator for receiving the link output voltage and for generating a target current proportionate to the rectified line input voltage; and

a finite state machine configured to operate the switch-mode boost stage in a hybrid discontinuous conduction mode (DCM)/continuous conduction mode (CCM) mode and;

wherein the finite state machine defines a switching period for a control signal for controlling the switch based on an on-time duration of the switch, an off-time duration of the switch, an N number of switching pulses defined within the switching period wherein N is an integer greater than one and wherein an inductor current through the inductor is zero before an initial switching pulse of the N number of switching pulses, is zero after a last switching pulse of the N number of switching pulses, and is non-zero for all other times within the switching period; and

wherein the N number of switching pulses is three switching pulses and the hybrid DCM/CCM mode is a hybrid DCM/CCM triple-pulse mode.

22. A power factor corrector (PFC), comprising:

a switch-mode boost stage having a switch and an inductor coupled to the switch wherein the switch-mode boost stage receives a rectified line input voltage and provides a link output voltage;

a target current generator for receiving the link output voltage and for generating a target current proportionate to the rectified line input voltage; and

a finite state machine configured to operate the switch-mode boost stage in a hybrid discontinuous conduction mode (DCM)/continuous conduction mode (CCM) mode and;

wherein the finite state machine defines a switching period for a control signal for controlling the switch based on an on-time duration of the switch, an off-time duration of the switch, an N number of switching pulses defined within the switching period wherein N is an integer greater than one and wherein an inductor current through the inductor is zero before an initial switching pulse of the N number of switching pulses, is zero after a last switching pulse of the N number of switching pulses, and is non-zero for all other times within the switching period; and

wherein for a subsequent switching pulse after the initial switching pulse and before the last switching pulse, the switch is turned on for a fraction of the on-time duration and the switch is turned off for the fraction of the off-time duration, wherein the fraction is greater than zero and less than one and is defined by a ratio of a width of the subsequent switching pulse to a width of the initial switching pulse.

23. The PFC of claim 22 wherein the fraction is selected as an optimal value in a range between 0.25 and 0.50.