Systems and methods for regulating output currents of power conversion systems

Patent metadata

Field	Value
Publication number	US-9564811-B2
Application number	US-201414272323-A
Country	US
Kind code	B2
Filing date	May 7, 2014
Priority date	Apr 18, 2014
Publication date	Feb 7, 2017
Grant date	Feb 7, 2017

Abstract

Systems and methods are provided for regulating a power conversion system. An example system controller includes a first controller terminal and a second controller terminal. The first controller terminal is configured to receive a first signal associated with an input signal for a primary winding of a power conversation system. The second controller terminal is configured to output a drive signal to a switch to affect a first current flowing through the primary winding of the power conversion system, the drive signal being associated with an on-time period, the switch being closed during the on-time period. The system controller is configured to adjust a duration of the on-time period based on at least information associated with the first signal.

First claim

What is claimed is:

1. A system controller for regulating a power conversion system, the system contoller comprising:
a first controller terminal configured to receive a first signal associated with an input signal for a primary winding of the power conversation system;
a second controller terminal configured to output a drive signal to a switch to affect a first current flowing through the primary winding of the power conversion system, the drive signal being associated with an on-time period, the switch being closed during the on-time period;
a first conversion component configured to generate a second current based on at least information associated with the first signal; and
a ramp-signal generator configured to generate a ramping signal based on at least information associated with the second current, the ramping signal being associated with a ramping slope;
wherein the system controller is configured to adjust a duration of the on-time period based on at least information associated with the first signal;
wherein the system controller is further configured to adjust the duration of the on-time period by adjusting the ramping slope of the ramping signal based on at least information associated with the first signal.

2. The system controller of claim 1 wherein the input signal corresponds to an input voltage.

3. A system controller for regulating a power conversion system, the system controller comprising:
a first controller terminal configured to receive a first signal associated with an input signal for a primary winding of the power conversation system; and
a second controller terminal configured to output a drive signal to a switch to affect a first current flowing through the primary winding of the power conversion system, the drive signal being associated with an on-time period, the switch being closed during the on-time period;
wherein the system controller is configured to adjust a duration of the on-time period based on at least information associated with the first signal;
wherein:
the first controller terminal is coupled to a first resistor terminal of a first resistor;
a second resistor terminal of the first resistor is configured to receive the input signal;
the first resistor terminal is coupled to a third resistor terminal of a second resistor;
a fourth resistor terminal of the second resistor is biased at a predetermined voltage; and
the first resistor terminal of the first resistor is configured to provide the first signal.

4. The system controller of claim 1 , further comprising:
a third controller terminal configured to provide a compensation signal based on at least information associated with the first current; and
a second conversion component configured to generate a third current based on at least information associated with the compensation signal.

5. The system controller of claim 4 wherein the ramp-signal generator is configured to generate the ramping signal based on at least information associated with the second current and the third current.

6. The system controller of claim 4 wherein:
the ramp-signal generator is configured to increase the ramping signal at the ramping slope from a first magnitude to a second magnitude during the on-time period;
the first magnitude is equal to a reference signal in magnitude; and
the second magnitude is equal to the compensation signal in magnitude.

7. The system controller of claim 4 wherein the ramp-signal generator includes:
a processing component configured to generate a charging current based on at least information associated with the second current and the third current; and
a capacitor configured to be charged in response to the charging current to generate the ramping signal, the capacitor being associated with a capacitance.

8. The system controller of claim 7 wherein the ramping slope of the ramping signal is related to the charging current and the capacitance.

9. The system controller of claim 7 wherein the duration of the on-time period is related to the compensation signal, the charging current and the capacitance.

10. The system controller of claim 7 wherein the processing component includes one or more current-mirror circuits.

11. The system controller of claim 7 , further comprising a modulation component configured to receive the ramping signal and the compensation signal and output a modulation signal based on at least information associated with the ramping signal and the compensation signal to affect the drive signal.

12. The system controller of claim 7 , further comprising an error amplifier configured to receive a sensing signal associated with the first current and a reference signal and outputs the compensation signal based on at least information associated with the sensing signal and the reference signal.

13. The system controller of claim 7 , further comprising:
a transistor including a first transistor terminal, a second transistor terminal and a third transistor terminal;
wherein:
the first transistor terminal is configured to receive a control signal;
the second transistor terminal is configured to receive a second signal associated with the reference signal; and
the third transistor terminal is coupled to a first capacitor terminal of the capacitor and is configured to receive the ramping signal.

14. The system controller of claim 4 wherein:
the first conversion component is further configured to generate the second current flowing into the first conversion component; and
the second conversion component is further configured to generate the third current flowing into the second conversion component.

15. The system controller of claim 4 wherein:
the first conversion component is further configured to generate the second current flowing out of the first conversion component; and
the second conversion component is further configured to generate the third current flowing out of the second conversion component.

16. The system controller of claim 1 , further comprising:
a jittering-signal generator configured to generate a jittering signal associated with multiple jittering cycles corresponding to a predetermined jittering frequency related to a predetermined jittering period;
wherein:
the drive signal is associated with multiple modulation cycles corresponding to a modulation frequency related to a modulation period; and
the system controller is further configured to:
change the ramping slope based on at least information associated with the jittering signal so that, within a same jittering cycle of the multiple jittering cycles, the ramping slope is changed by different magnitudes corresponding to the multiple modulation cycles respectively; and
adjust the modulation frequency based on at least information associated with the changed ramping slope.

17. The system controller of claim 1 , further comprising:
a jittering-signal generator configured to generate a random jittering signal;
wherein:
the drive signal is associated with multiple modulation cycles corresponding to a modulation frequency related to a modulation period;
the system controller is further configured to:
change the ramping slope based on at least information associated with the random jittering signal so that the ramping slope is changed by random magnitudes corresponding to the multiple modulation cycles respectively; and
adjust the modulation frequency based on at least information associated with the ramping slope changed by the random magnitudes.

18. The system controller of claim 1 , further comprising:
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Assignees

• On Bright Electronics Shanghai Co Ltd

Inventors

• Zhai Xiangkun
• Zhang Yunchao
• Zhou Jun
• Fang Lieyi

Classifications

• H03K17/16

  Modifications for eliminating interference voltages or currents · CPC title

• H02M1/36

  Means for starting or stopping converters · CPC title

• H03K3/012

  Modifications of generator to improve response time or to decrease power consumption · CPC title

• H03K17/723

  using transformer coupling · CPC title

• H02M3/33507 Primary

  with automatic control of the output voltage or current, e.g. flyback converters (H02M3/33561, H02M3/33569 take precedence) · CPC title