Systems and methods of primary-side sensing and regulation for flyback power converter with high stability

A method for regulating an output voltage of a power conversion system, the method comprising:

• receiving a reference voltage, a first voltage, and an adjustment current by an error amplifier, the first voltage being associated with a feedback voltage;
• processing information associated with the reference voltage, the first voltage and the adjustment current;
• generating a compensation voltage based on at least information associated with the reference voltage, the first voltage and the adjustment current;
• receiving the compensation voltage;
• generating the adjustment current and a first current based on at least information associated with the compensation voltage;
• receiving the first current, a second current, and a sensing voltage;
• generating a modulation signal based on at least information associated with the first current, the second current, and the sensing voltage;
• processing information associated with the modulation signal;
• generating a drive signal based on at least information associated with the modulation signal;
• and
• outputting the drive signal to a switch in order to affect a third current of a power conversion system;
• wherein:
• the feedback voltage is associated with an output voltage and an output current of the power conversion system;
• and
• the sensing voltage is associated with the third current;
• wherein:
• the error amplifier is characterized by a transconductance;
• the process for processing information associated with the reference voltage, the first voltage and the adjustment current includes changing the transconductance based on at least information associated with the adjustment current;
• and
• the transconductance decreases with the decreasing output current of the power conversion system.

A system for regulating an output voltage of a power conversion system, the system comprising:

• an error amplifier indirectly coupled to a capacitor through a first switch, the error amplifier being configured to receive a reference voltage and a first voltage and to generate a compensation voltage with the capacitor in response to the first switch being closed, the first voltage being associated with a feedback voltage;
• a signal generator configured to receive the compensation voltage, a first current, and a sensing voltage and to generate a control signal based on at least information associated with the compensation voltage, the first current, and the sensing voltage;
• and
• a driving component configured to receive the control signal and configured to generate a drive signal based on at least information associated with the control signal and output the drive signal to a second switch in order to affect a second current flowing through a primary winding of a power conversion system;
• wherein:
• the feedback voltage is associated with an output voltage and an output current of the power conversion system;
• and
• the sensing voltage is associated with the second current;
• wherein:
• the control signal is characterized by a pulse width and a switching frequency;
• the first switch is configured to be controlled by the control signal;
• the first switch is configured to be closed in response to the control signal being at a logic high level;
• and
• the first switch is configured to be opened in response to the control signal being at a logic low level.

A method for regulating an output voltage of a power conversion system, the method comprising:

• receiving a reference voltage and a first voltage by an error amplifier, the first voltage being associated with a feedback voltage, the error amplifier indirectly coupled to a capacitor through a first switch;
• processing information associated with the reference voltage and the first voltage;
• generating a compensation voltage in response to the first switch being closed;
• receiving the compensation voltage, a first current, and a sensing voltage;
• generating a control signal based on at least information associated with the compensation voltage, the first current, and the sensing voltage;
• processing information associated with the control signal;
• generating a drive signal based on at least information associated with the control signal;
• and
• outputting the drive signal to a second switch in order to affect a second current flowing through a primary winding of a power conversion system;
• wherein:
• the feedback voltage is associated with an output voltage and an output current of the power conversion system;
• and
• the sensing voltage is associated with the second current;
• wherein:
• the control signal is characterized by a pulse width and a switching frequency;
• and
• the process for processing information associated with the control signal includes closing the first switch in response to the control signal being at a logic high level and opening the first switch in response to the control signal being at a logic low level.

A system for regulating an output voltage of a power conversion system, the system comprising:

• an error amplifier indirectly coupled to a capacitor through a first switch, the error amplifier being configured to receive a reference voltage and a first voltage and to generate a compensation voltage with the capacitor in response to the first switch being closed, the first voltage being associated with a feedback voltage;
• a signal generator configured to receive the compensation voltage, a first current, and a sensing voltage and to generate a control signal based on at least information associated with the compensation voltage, the first current, and the sensing voltage;
• a one-shot generator configured to receive the control signal and sends a one-shot signal to the first switch;
• and
• a driving component configured to generate a drive signal based on at least information associated with the control signal and output the drive signal to a second switch in order to affect a second current flowing through a primary winding;
• wherein:
• the feedback voltage is associated with an output voltage and an output current of the power conversion system;
• and
• the sensing voltage is associated with at least the second current;
• wherein:
• the control signal is characterized by a first pulse width and a first switching frequency;
• the one-shot signal is characterized by a second pulse width and a second switching frequency;
• the second pulse width is a constant determined by the one-shot generator;
• the second switching frequency is equal to the first switching frequency;
• the first switch is configured to be controlled by the one-shot signal;
• the first switch is configured to be closed in response to the one-shot signal being at a logic high level;
• and
• the first switch is configured to be opened in response to the one-shot signal being at a logic low level.

A method for regulating an output voltage of a power conversion system, the method comprising:

• receiving a reference voltage and a first voltage by an error amplifier, the first voltage being associated with a feedback voltage, the error amplifier indirectly coupled to a capacitor through a first switch;
• processing information associated with the reference voltage and the first voltage;
• generating a compensation voltage in response to the first switch being closed;
• receiving the compensation voltage, a first current, and a sensing voltage;
• generating a control signal based on at least information associated with the compensation voltage, the first current, and the sensing voltage;
• processing information associated with the control signal;
• generating a one-shot signal and a drive signal based on at least information associated with the control signal;
• adjusting the first switch based on information associated with the one-shot signal;
• and
• outputting the drive signal to a second switch in order to affect a second current flowing through a primary winding of a power conversion system;
• wherein:
• the feedback voltage is associated with an output voltage and an output current of the power conversion system;
• and
• the sensing voltage is associated with the second current;
• wherein:
• the control signal is characterized by a first pulse width and a first switching frequency;
• the one-shot signal is characterized by a second pulse width and a second switching frequency;
• the second pulse width is a constant determined by the one-shot generator;
• the second switching frequency is equal to the first switching frequency;
• and
• the process for adjusting the first switch based on information associated with the one-shot signal includes closing the first switch in response to the one-shot signal being at a logic high level and opening the first switch in response to the one-shot signal being at a logic low level.