Leadtrend Technology Corporation

San-Yi Li

Hsin-Hung Lu

Hung-Ting Hsu

Hung-Ching Lee

Yao-Tsung Chen

Mao-Shih Li

Jun-Hao Huang

Hsin Hung Lu

A control method is disclosed to have a voltage sample capable of more correctly representing an output voltage of a power converter. The power converter has a primary side and a secondary side galvanically isolated from each other. A feedback voltage is received in the primary side. A main power switch is turned OFF, starting an OFF time, during which the feedback voltage is constrained in response to the voltage sample. In a sampling time within the OFF time, the feedback voltage is sampled to update the voltage sample representing the output voltage in the secondary side. A driving signal is provided in response to the voltage sample to control the main power switch.

Control method and power controller for flyback power converter

A method of switching operational modes of a power converter includes starting up a primary controller applied to the power converter to make the power converter operate in a normal mode; a secondary controller applied to the power converter detecting an output voltage of a secondary side of the power converter and the primary controller detecting an operational frequency of the power converter; if the operational frequency of the power converter is lower than a predetermined frequency and satisfies a first frequency condition, the primary controller controlling the power converter to enter a sleep mode; and when the power converter enters the sleep mode and the output voltage is lower than a trigger voltage, the secondary controller making the primary controller to control the power converter turned on.

Method of switching operational modes of a power converter

A primary controller applied to a primary side of a power converter includes a ripple cancellation circuit, a compensation voltage generation circuit, and a gate control signal generation circuit. The ripple cancellation circuit generates an adjustment according to a current flowing through a feedback pin of the primary controller during turning-on of a power switch of the primary side of the power converter. The compensation voltage generation circuit generates a compensation voltage of a compensation pin of the primary controller according to the adjustment, a reference voltage, and a feedback voltage of the feedback pin. The gate control signal generation circuit generates a gate control signal to the power switch to reduce an output voltage of a secondary side of the power converter according to the compensation voltage and a detection voltage.

Primary controller applied to a primary side of a power converter and operational method thereof

A control circuit for compensating output loss of a power converter includes a sampling voltage generator, a time-to-voltage converter, and a compensation signal generator. The sampling voltage generator generates a sampling voltage corresponding to a detection voltage according to a first reference current, a second reference current, and the detection voltage. The time-to-voltage converter generates a corresponding voltage according to a period of a gate control signal controlling a power switch of a primary side of the power converter and a discharge time of a secondary side of the power converter. The compensation signal generator generates a compensation signal compensating the output loss according to the sampling voltage and the corresponding voltage.

Control circuit for compensating output loss of a power converter and method thereof

A secondary controller applied to a secondary side of a power converter includes a detector and a standby signal generation circuit. The detector is used for detecting a first signal and a second signal of a universal serial bus device, and a frequency of a synchronization signal corresponding to a primary side of the power converter. The standby signal generation circuit is coupled to the detector for delaying a first predetermined time to generate a standby signal to a primary controller of the primary side of the power converter when the detector fails to detect the first signal and the second signal, and the frequency of the synchronization signal is less than a first predetermined frequency, wherein the primary controller enters a standby mode according to the standby signal.

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Hsinchu County, Taiwan

San-Yi Li