SYSTEMS AND METHODS FOR OUTPUT CURRENT REGULATION IN POWER CONVERSION SYSTEMS

• US 20150311804A1
• Filed: 05/08/2014
• Published: 10/29/2015
• Est. Priority Date: 04/23/2014
• Status: Active Grant

• Current Assignee: Guangzhou On-Bright Electronics Co., Ltd
• Original Assignee: Guangzhou On-Bright Electronics Co., Ltd
• Inventors: Fang, Lieyi
• Granted Patent: US 9,986,605 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G05F 1/00 Automatic systems in which deviations of an electric quantity from one or more predetermined values are detected at the output of the system and fed back to a device within the system to restore the detected quantity to its predetermined value or values, i.e. retroactive systems
• CPC Class Codes: H02M 3/156 with automatic control of output voltage or current, e.g. switching regulators
• CPC Class Codes: H02M 3/158 including plural semiconductor devices as final control devices for a single load
• CPC Class Codes: H02M 3/1582 Buck-boost converters H02M3/1584 takes precedence
• CPC Class Codes: H02M 3/335 using semiconductor devices only
• CPC Class Codes: H02M 7/2176 comprising a passive stage to generate a rectified sinusoidal voltage and a controlled switching element in series between such stage and the output
• CPC Class Codes: H05B 45/00 Circuit arrangements for operating light-emitting diodes [LED]
• CPC Class Codes: H05B 45/3725 Switched mode power supply [SMPS]
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

Systems and methods are provided for regulating a power conversion system. An example system controller includes: a detection component configured to receive an input voltage related to a diode connected to an inductor and output a first signal at a first logic level in response to the input voltage being larger than a predetermined threshold, a control logic component configured to receive the first signal, process information associated with the first signal, and output a modulation signal related to a modulation frequency in response to the first signal being at the first logic level, and a driving component configured to receive the modulation signal and output a drive signal to open and close a first switch at the modulation frequency.

Claims

1. A system controller for regulating a power conversion system, the system controller comprising:

a detection component configured to receive an input voltage related to a diode connected to an inductor and output a first signal at a first logic level in response to the input voltage being larger than a predetermined threshold;

a control logic component configured to receive the first signal, process information associated with the first signal, and output a modulation signal related to a modulation frequency in response to the first signal being at the first logic level; and

a driving component configured to receive the modulation signal and output a drive signal to open and close a first switch at the modulation frequency, so that in response to the first switch being closed, the inductor is configured to output a first current through the switch and in response to the first switch being open, the inductor is configured to output a second current through the diode.

2. The system controller of claim 1 wherein:

the diode includes a first diode terminal and a second diode terminal;

the inductor includes a first inductor terminal and a second inductor terminal;

the first diode terminal is coupled to the first inductor terminal; and

the second diode terminal is configured to receive a first voltage related to the input voltage.

3. The system controller of claim 2 wherein the first voltage is proportional to the input voltage.

4. The system controller of claim 2 wherein the second inductor terminal is coupled to a capacitor.

5. The system controller of claim 1 wherein the detection component includes:

an input detector configured to receive the input voltage and output a detection signal based on at least information associated with the input voltage; and

an enable component configured to receive the detection signal and output the first signal based on at least information associated with the detection signal.

6. The system controller of claim 1 wherein the diode is directly connected to the inductor.

7. The system controller of claim 1 wherein the detection component is further configured to output the first signal at a second logic level in response to the input voltage being smaller than the predetermined threshold.

8. A system controller for regulating a power conversion system, the system controller comprising:

a first transistor including a first transistor terminal, a second transistor terminal, and a third transistor terminal, the first transistor terminal being coupled to a fourth transistor terminal of a second transistor, the second transistor further including a fifth transistor terminal and a sixth transistor terminal;

wherein;

the fifth transistor terminal is coupled to a first resistor terminal of a first resistor, the first resistor further including a second resistor terminal;

the fifth transistor terminal is coupled to a first diode terminal of a first diode, the first diode further including a second diode terminal;

the second diode terminal is coupled to the second resistor terminal;

wherein the system controller is configured to change a first voltage of the fourth transistor terminal to turn on and off the second transistor and to affect a current flowing through an inductor.

9. The system controller of claim 8 is further configured to keep a second voltage of the fifth transistor terminal constant and change the first voltage of the fourth transistor terminal to turn on and off the second transistor and to affect the current flowing through the inductor.

10. The system controller of claim 8, further comprising:

a first controller terminal coupled to the second resistor terminal and the second diode terminal; and

a second diode including a third diode terminal and a fourth diode terminal, the third diode terminal being coupled to the first controller terminal, the fourth diode terminal being coupled to the first transistor terminal.

11. The system controller of claim 10, further comprising:

a clamping component configured to keep a second voltage associated with the first controller terminal from exceeding a predetermined threshold.

12. The system controller of claim 10 wherein the first controller terminal is coupled to a capacitor including a first capacitor terminal and a second capacitor terminal.

13. The system controller of claim 10 wherein the first capacitor terminal is coupled to the second resistor terminal and the second diode terminal.

14. A system controller for regulating a power conversion system, the system controller comprising:

a detection component configured to detect one or more peak magnitudes of a current sensing signal associated with a first current from an inductor flowing through a switch and generate an output signal based on at least information associated with the detected one or more peak magnitudes of the current sensing signal;

an error amplifier configured to receive the output signal and a reference signal and generate an amplified signal based on at least information associated with the output signal and the reference signal;

a comparator configured to receive the current sensing signal and a first signal associated with the amplified signal and output a comparison signal based on at least information associated with the first signal and the current sensing signal; and

a control-and-drive component configured to receive the comparison signal and output a drive signal based on at least information associated with the comparison signal to close or open the switch to affect the first current.

15. The system controller of claim 14, further comprising:

a compensation network component configured to receive the amplified signal and output the first signal based on at least information associated with the amplified signal.

16. The system controller of claim 14 wherein:

the inductor is coupled to a diode;

in response to the switch being closed, the inductor is configured to output the first current through the switch; and

in response to the switch being open, the inductor is configured to output a second current through the diode.

17. The system controller of claim 14 wherein:

in response to the comparison signal being at a first logic level, the control-and-drive component is further configured to open the switch; and

in response to the comparison signal being at a second logic level, the control-and-drive component is further configured to close the switch.

18. The system controller of claim 14 wherein the detection component includes a sampling component configured to sample the one or more peak magnitudes of the current sensing signal.

19. A system controller for regulating a power conversion system, the system controller comprising:

a protection component configured to receive a first signal and a second signal and generate a third signal based on at least information associated with the first signal and the second signal, the first signal being associated with a demagnetization period related to an inductor, the second signal being associated with a first current flowing through the inductor; and

a control-and-drive component configured to receive the third signal and output a drive signal to the switch to affect the first current;

wherein;

the protection component is further configured to, in response to,

the second signal indicating, during a first switching cycle associated with the drive signal, that the first current is equal to or larger than a current threshold, and

the first signal indicating, during an off-time period of the first switching cycle, that the demagnetization period is smaller than a predetermined time period,

change the third signal from a first signal state to a second signal state to cause the power conversion system to be shut down.

20. The system controller of claim 19 wherein the control-and-drive component is further configured to, in response to the third signal being at the first signal state, output the drive signal to close or open the switch.

21. The system controller of claim 19 wherein the protection component is further configured to, in response to the third signal being changed from the first signal state to the second signal state, keep the third signal at the second signal state regardless of the first signal and the second signal.

22. The system controller of claim 19, further comprising:

a comparator configured to receive a current sensing signal associated with the first current and a threshold signal associated with the current threshold and generate the second signal based on at least information associated with the current sensing signal and the threshold signal.

23. The system controller of claim 19, further comprising a comparison component configured to receive a detection signal associated with the demagnetization period, process information associated with the detection signal and the predetermined time period, and generate the first signal based on at least information associated with the detection signal.

24. The system controller of claim 19, further comprising:

a maximum-on-time component configured to determine whether an on-time period of a second switching cycle associated with the drive signal exceeds a maximum on-time period and generate a fourth signal based on at least information associated with the on-time period;

wherein the control-and-drive component is further configured to, in response to the fourth signal indicating the on-time period exceeds the maximum on-time period, end the on-time period of the second switching cycle and change the drive signal to open the switch.

25. The system controller of claim 19, wherein the control-and-drive component includes:

a control-logic component configured to receive the protection signal and generate a modulation signal; and

a driving component configured to receive the modulation signal and output the drive signal based on at least information associated with the modulation signal.

26. The system controller of claim 25 wherein the protection component is further configured to receive the modulation signal and detect an end of the off-time period of the first switching cycle.

27. A method for regulating a power conversion system, the method comprising:

receiving an input voltage related to a diode connected to an inductor;

processing information associated with the input signal;

outputting a first signal at a first logic level in response to the input voltage being larger than a predetermined threshold;

receiving the first signal;

processing information associated with the first signal;

outputting a modulation signal related to a modulation frequency in response to the first signal being at the first logic level;

receiving the modulation signal;

processing information associated with the modulation signal;

outputting a drive signal to open and close a first switch at the modulation frequency;

in response to the first switch being closed, outputting a first current through the switch; and

in response to the first switch being open, outputting a second current through the diode.

28. A method for regulating a power conversion system, the method comprising:

sampling one or more peak magnitudes of a current sensing signal associated with a first current from an inductor flowing through a switch;

generating an output signal based on at least information associated with the detected one or more peak magnitudes of the current sensing signal;

receiving the output signal and a reference signal;

processing information associated with the output signal and the reference signal;

generating an amplified signal based on at least information associated with the output signal and the reference signal;

receiving the current sensing signal and a first signal associated with the amplified signal;

processing information associated with the current sensing signal and the first signal;

outputting a comparison signal based on at least information associated with the first signal and the current sensing signal;

receiving the comparison signal;

processing information associated with the comparison signal; and

outputting a drive signal based on at least information associated with the comparison signal to close or open the switch to affect the first current.

29. A method for regulating a power conversion system, the method comprising:

receiving a first signal and a second signal;

processing information associated with the first signal and the second signal;

generating a third signal based on at least information associated with the first signal and the second signal, the first signal being associated with a demagnetization period related to an inductor, the second signal being associated with a first current flowing through the inductor;

receiving the third signal;

processing information associated with the third signal;

outputting a drive signal to the switch to affect the first current; and

in response to, the second signal indicating, during a first switching cycle associated with the drive signal, that the first current is equal to or larger than a current threshold and the first signal indicating, during an off-time period of the first switching cycle, that the demagnetization period is smaller than a predetermined time period, changing the third signal from a first signal state to a second signal state to cause the power conversion system to be shut down.