Abstract: A control circuit of a power converter includes: an input signal detection circuit, configured to operably detect a magnitude of an input signal to generate a detection signal; a clock generation circuit, configured to operably generate a clock signal; an error detection circuit, configured to operably generate an error signal according to a reference signal and a feedback signal; a control signal generation circuit, coupled with the clock generation circuit and the error detection circuit, configured to operably control a switching frequency of a power switch according to the clock signal and the error signal; and a reverse adjusting circuit, coupled with the input signal detection circuit, configured to operably adjust the clock generation circuit or the control signal generation circuit according to the detection signal to configure the switching frequency of the power switch to be inversely proportional to the magnitude of the input signal.

Abstract: The present invention discloses a flyback power supply circuit with a programmable function and a control method thereof. The flyback power supply circuit includes: a transformer circuit, a power switch circuit, a primary side control circuit, an opto-coupler circuit, and a secondary side control circuit. The primary side control circuit determines whether an over voltage condition occurs, and further determines whether to generate an over voltage protection signal to turn OFF a power switch of the power switch circuit according to a rate of increase of a feedback signal and a control level, or according to the rate of increase of the feedback signal and a rate of change of a target control signal.

Abstract: The present invention provides a flyback power converter with a programmable output and a control circuit and a control method thereof. The flyback power converter converts an input voltage to a programmable output voltage according to a setting signal, wherein the programmable output voltage switches between different levels. The flyback power converter includes: a transformer circuit, a power switch circuit, a current sense circuit, an opto-coupler circuit, and a control circuit. The control circuit adaptively adjusts an operation signal according to a level of the programmable output voltage, to maintain a same or relatively higher operation frequency of the operation signal when the programmable output voltage switches to a relatively lower level, so as to maintain a phase margin while supplying the same output current.

Abstract: A voltage converting controller. When output current increases from a first current value to a second current value, the voltage converting controller temporarily sets a control frequency to a maximum frequency value. After a period of time, the voltage converting controller sets the control frequency to a target control frequency corresponding to the second current value. And, when the output current increases from the first current value to the second current value, the voltage converting controller temporarily sets a secondary-side output voltage to an transient output value; and after a period of time, the voltage converting controller sets a steady state value of the secondary-side output voltage to an output voltage steady state value corresponding to the second current value.

Abstract: A parameter setting and circuit protecting method applied in a power converter are disclosed. An input voltage of the power converter is detected to generate a first detecting signal related to the input voltage. The first detecting signal will be thence compared with a threshold so as to generate a protecting signal for protecting the power converter. When a parameter setting signal is triggered, a current is provided so as to make the first detecting signal to generate a variation, thereby setting a parameter in accordance with the variation.

Abstract: A voltage converting controller, in which when an output current increases from a first current value to a second current value, the voltage converting controller temporarily sets a control frequency to a maximum frequency value; and after a period of time, sets the control frequency to a target control frequency corresponding to the second current value. In addition, when the output current increases from the first current value to the second current value, the voltage converting controller temporarily sets a secondary-side output voltage to an transient output value; and after a period of time, sets a steady state value of the secondary-side output voltage to an output voltage steady state value corresponding to the second current value.

Abstract: A voltage converting controller, in which when an output current increases from a first current value to a second current value, the voltage converting controller temporarily sets a control frequency to a maximum frequency value; and after a period of time, sets the control frequency to a target control frequency corresponding to the second current value. In addition, when the output current increases from the first current value to the second current value, the voltage converting controller temporarily sets a secondary-side output voltage to an transient output value; and after a period of time, sets a steady state value of the secondary-side output voltage to an output voltage steady state value corresponding to the second current value.

Abstract: A voltage converting controller. When output current increases from a first current value to a second current value, the voltage converting controller temporarily sets a control frequency to a maximum frequency value. After a period of time, the voltage converting controller sets the control frequency to a target control frequency corresponding to the second current value. And, when the output current increases from the first current value to the second current value, the voltage converting controller temporarily sets a secondary-side output voltage to an transient output value; and after a period of time, the voltage converting controller sets a steady state value of the secondary-side output voltage to an output voltage steady state value corresponding to the second current value.

Abstract: The present invention discloses a flyback power supply circuit with a programmable function and a control method thereof. The flyback power supply circuit includes: a transformer circuit, a power switch circuit, a primary side control circuit, an opto-coupler circuit, and a secondary side control circuit. The primary side control circuit determines whether an over voltage condition occurs, and further determines whether to generate an over voltage protection signal to turn OFF a power switch of the power switch circuit according to a rate of increase of a feedback signal and a control level, or according to the rate of increase of the feedback signal and a rate of change of a target control signal.

Abstract: A power off delay circuit includes a switch connected between an external power input terminal and an internal power supply terminal, a capacitor connected to the internal power supply terminal, and a hysteresis comparator to switch the switch according to the voltages of the external power input terminal and the internal power supply terminal. During on-time of the switch, the external power input terminal is connected to the internal power supply terminal and the capacitor can be charged by the external power source. When the switch is off, the capacitor provides electric power for an internal circuit. Application of the power off delay circuit to an audio system may eliminate the turn-off pops of the audio system.

Abstract: A switching power converting apparatus includes a voltage conversion module, a detecting unit, and a switching signal generating unit. The voltage conversion module converts an input voltage into an output voltage associated with a secondary side current, which flows through a secondary winding of a transformer and is generated based on a switching signal. The detecting unit generates a detecting signal based on the output voltage and a predetermined reference voltage. The switching signal generating unit generates the switching signal based on the detecting signal and an adjusting signal so that the secondary side current is gradually increased during a start period of the switching power converting apparatus.

Abstract: A bleeding circuit and method for an electromagnetic interference filter detect whether or not an AC power source connected to the electromagnetic interference filter is removed, establish a discharge path for discharging a capacitor of the electromagnetic interference filter once the connected AC power source is removed, and cut off the discharge path during the AC power source is in connection to the electromagnetic interference filter for decreasing power consumption of the electromagnetic interference filter.

Abstract: The present invention provides a flyback power converter and a control circuit. The flyback power converter includes a transformer which has a primary winding, a secondary winding, and an auxiliary winding; a power switch controlling the conduction of the primary winding; and a control circuit generating a control signal to control the power switch, wherein the control circuit is an integrated circuit having a current sensing pin for obtaining a current sensing signal of a current through the power switch. The flyback power converter further includes a temperature-sensitive resistor or a mode detection resistor coupled between the auxiliary winding and the current sensing pin, for providing a temperature-related signal for the control circuit to perform an over-temperature protection, or for providing a mode detection signal for the control circuit to determine an operation mode of the flyback power converter.

Abstract: An LED control device for configuring a phase-cut dimming system includes an LED and a switch. The LED control device configures the conduction status of the switch so as to supply power to the LED according to an input signal. The LED control device further detects whether the input signal is phase-cut. When the input signal is phase-cut, the LED control device stores the signal values of the internal circuits. Afterward, when the input signal is not phase-cut, the LED control device restores the stored signal values so that the internal circuits may resume to the previous operation status rapidly.

Abstract: A switching power converting apparatus is capable of converting an input voltage to an output voltage, and includes a transformer, a primary side control module, and a secondary side control module. The secondary side control module utilizes voltage clamping techniques or current-drawing techniques to stop self-excited conversion from the input voltage to the output voltage when the output voltage is greater than a predetermined target voltage, or utilizes a non-self-excited conversion architecture.

Abstract: A switching power converting apparatus includes a voltage conversion module, a detecting unit, and a switching signal generating unit. The voltage conversion module converts an input voltage into an output voltage associated with a secondary side current, which flows through a secondary winding of a transformer and is generated based on a switching signal. The detecting unit generates a detecting signal based on the output voltage and a predetermined reference voltage. The switching signal generating unit generates the switching signal based on the detecting signal and an adjusting signal so that the secondary side current is gradually increased during a start period of the switching power converting apparatus.

Abstract: A switching power converting apparatus includes a voltage conversion module, a detecting unit, and a switching signal generating unit. The voltage conversion module converts an input voltage into an output voltage associated with a secondary side current, which flows through a secondary winding of a transformer and is generated based on a switching signal. The detecting unit generates a detecting signal based on the output voltage and a predetermined reference voltage. The switching signal generating unit generates the switching signal based on the detecting signal and an adjusting signal so that the secondary side current is gradually increased during a start period of the switching power converting apparatus.

Abstract: A mixed mode compensation circuit and method for a power converter generate a digital signal according to a reference value and a feedback signal which is related to the output voltage of the power converter, convert the digital signal into a first analog signal, offset the first analog signal with a variable offset value to generate a second analog signal, and filter out high-frequency components of the second analog signal to generate a third analog signal for stable output voltage of the power converter. The mixed mode compensation does not require large capacitors, and thus the circuit can be integrated into an integrated circuit.

Abstract: A bootstrap circuit includes: a charging voltage source; a charging diode, having an anode coupled to the charging voltage source; a high-voltage transistor, having a control terminal defined as a first connecting node and a channel coupled between a cathode of the charging diode and a bootstrap capacitor; a logic control circuit, having a first and a second logic outputs, and a logic input for receiving a charging command; a high-voltage control transistor, having a control terminal defined as a second connecting node and a channel coupled between charging voltage source and the first connecting node; a cut-off resistor, coupled between the first and the second connecting nodes; a charging control transistor, having a channel coupled between the second connecting node and a ground terminal, and a control terminal coupled to the second logic output; a control capacitor, coupled between the first connecting node and the first logic output.

Abstract: A control circuit for a power converting circuit includes a multifunctional pin, a pulse-width-modulation (PWM) signal generating circuit, a voltage detecting circuit and a zero current detecting circuit. The voltage detecting circuit detects a signal on the multifunctional pin. When the signal on the multifunctional pin is greater than a predetermined value, the voltage detecting circuit configures the PWM signal generating circuit to intermittently conduct a current switch of the power converting circuit. The zero current detecting circuit detects the signal of the multifunctional pin to determine the conduction status of the current switch. When the signal of the multifunctional pin is less than the predetermined value, the voltage detecting circuit configures the PWM signal generating circuit to turn off the current switch.