Abstract: The present invention provides an LED current balance apparatus, which utilities capacitances coupled to secondary windings of a transformer to store voltage differences between LED strings. Thereby, the driving voltages applied to LED strings are respectively modulated to make the LED strings flowing through a same driving current. A current regulating apparatus is coupled to all LED strings to stabilize total current of the LED strings at a predetermined current.

Abstract: A programmable on-time period of a DC to DC buck converting controller is adjusted according to a level of a preset output voltage or a reference signal. Therefore, the DC to DC buck converting controller of the present invention is suitable for any applications with different requests of output voltages or different operating mode.

Abstract: The present invention discloses an LED driving circuit and controller, capable of maintaining an average value of a current flowing through an LED module at a predetermined current value. The LED driving circuit and controller compensates influences of any factors deviating the average value of the current flowing through the LED module by modulating a period of constant on time or constant off time, or by modulating the determining value(s) of current peak value and/or current valley value according to a difference between an actual average value and the preset current value.

Abstract: The present invention provides a full-bridge driving controller and a full-bridge converting circuit, which have the function of soft switch, to provide a DC output voltage. The present invention employs a resonant unit to oscillate the current flowing through the converting circuit at a resonant frequency. The full-bridge driving controller switches four full-bridge transistor switches at an operating frequency higher than the resonant frequency, so as to achieve the function of soft switch.

Abstract: A converting controller comprises a power pin, a ground pin, at least one input pin, at least one output pin, at least one set pin and a failure generating circuit. The power pin is adapted to be coupled with a power source to receive electric power for operation, and the ground pin is adapted to be grounded. The input pin is adapted to receive a corresponding input signal and the output pin is used to output a corresponding output signal. The set pin is adapted to set a corresponding operating parameter of the converting controller. The failure generating circuit is coupled with and uses one of the input pin and the set pin as a protection output pin. The failure generating circuit modulates the level of the protection output pin to be a protection logic level when the converting controller is under a protection state.

Abstract: A controller with a multi-function pin, adapted to control a converting circuit according to a control signal for converting an input voltage into an output voltage, is disclosed. The controller has the multi-function pin, an enable unit, an over-current detecting unit and a logic control unit. The enable unit is coupled to the multi-function pin for receiving an enable signal and activates the controller in response to the enable signal. The over-current detecting is coupled to the multi-function pin and determines an over-current value according to an over-current set resistance coupled between the multi-function pin and a voltage source. The over-current detecting unit generates an over-current protection signal according to the over-current value and a current flowing through the converting circuit. The logic control unit determines whether executing an over-current protection according to the over-current protection signal.

Abstract: A controller for protectively reducing an output of a converting circuit includes a feedback circuit, a logic control circuit, an over-state judgment circuit, and a protection control circuit, is disclosed. The feedback circuit generates a modulation signal according to an output of a converting circuit. The logic control circuit is coupled to the feedback circuit and controls the converting circuit according to the modulation signal for stabilizing the output of the converting circuit. The over-state judgment circuit receives an over-state reference signal and a detecting signal, and generates a protection signal in response to levels of the detecting signal and the over-state reference signal. The protection control circuit is coupled to the logic control circuit and the over-state judgment circuit and controls the logic control circuit to lower the output of the converting circuit when receiving the protection signal.

Abstract: A power-good signal generator generates a power-good signal according to a control signal of a controller, and comprises an impedance element, a controlled transistor and a power sequencing free circuit. An end of the impedance element is coupled to a second voltage source. The controlled transistor has first and second input/output ends and a controlled end, wherein the first input/output end is coupled to the other end of the impedance element to generate the power-good signal. An operating state of the controlled transistor is changed in response to the control signal. The power sequencing free circuit is coupled to the controlled end and one of the first input/output end and the second voltage source. When the second voltage source is supplied before the first voltage source, the power sequencing free circuit turns on the controlled transistor to clamp the power-good signal to be lower than a predetermined voltage level.

Abstract: A current detecting circuit detects a resonant current in a primary side of a resonant converting circuit to generate a current detecting signal. An output detecting circuit generates a feedback signal according to the output voltage. A resonant controller generates a clock signal and adjusts an operating frequency of the clock signal in response to the feedback signal for modulating the output voltage of the resonant circuit. The resonant controller includes a resonance deviation protection unit which detects the current detecting signal according to a phase of the clock signal to determine whether the resonant circuit enters a region of zero current switching or not. When the resonant circuit enters the region of zero current switching, the resonant controller executes a corresponding protection process in response to that the resonant controller operates in a starting mode or a normal operating mode.

Abstract: A power converting circuit and a feedback control circuit for the power converting circuit are disclosed. The feedback control circuit comprises a feedback controller and a level controlling unit. The feedback controller generates a feedback control signal according to a reference voltage signal and a feedback signal. The level controlling unit receives one of the reference voltage signal and the feedback signal and modules a level of the received signal from a first level to a second level with time according to a level adjusting signal.

Abstract: A controller with protection function, for controlling a transistor having a control terminal, a first terminal coupled to a load, a second terminal, is disclosed. The controller comprises a judgment unit and a current control unit. The judgment unit is coupled to the transistor and generates a current reducing signal when a potential of the first terminal of the transistor or a voltage difference between the first terminal and the second terminal of the transistor is higher than a preset value. The current control unit is coupled to the control terminal of the transistor for substantially stabilizing the current flowing through the transistor at a preset current value, and reduces the current flowing from the preset current value when receiving the current reducing signal.

Abstract: An LED driving circuit comprises a converting circuit, a current regulator, a converting controller and a low dimming protection blocking circuit, is disclosed. The converting circuit is adapted to perform a power conversion to provide a driving voltage for lighting an LED module. The current regulator is coupled to the LED module for regulating a current flowing through the LED module. The current regulator conducts and stops conducting the current flowing through the LED module according to a dimming signal, and executes a protection process when the LED module operates abnormal. The converting controller controls the power conversion of the converting circuit according to a voltage level of at least one connection node of the current regulator and the LED module. The low dimming protection blocking circuit stops the protection process of the current regulator when the driving voltage is lower than a predetermined value.

Abstract: The resonant converting circuit comprises a resonant circuit, a current detecting circuit and the resonant controller. The resonant controller controls a power conversion of the resonant circuit for converting an input voltage into an output voltage and the resonant controller comprises an over current judgment unit and an over current protection unit. The over current judgment unit determines whether the resonant current is higher than an over current value according to a current detecting signal generated by the current detecting circuit. The over current protection unit generates a protection signal in response to a determined result of the over current judgment unit and an indication signal indicative of an operating state of the resonant controller. The resonant controller executes a corresponding protecting process in response to the protection signal.

Abstract: A controller with protection function, comprising a feedback circuit, a logic control circuit, an over-state judgment circuit, and a protection control circuit, is disclosed. The feedback circuit generates a modulation signal according to an output of a converting circuit. The logic control circuit is coupled to the feedback circuit and controls the converting circuit according to the modulation signal for stabilizing the output of the converting circuit. The over-state judgment circuit receives an over-state reference signal and a detecting signal, and generates a protection signal in response to levels of the detecting signal and the over-state reference signal. The protection control circuit is coupled to the logic control circuit and the over-state judgment circuit and controls the logic control circuit to lower the output of the converting circuit when receiving the protection signal.

Abstract: A multiphase control system is provided, which is adapted to convert power of an input power source into an output voltage for outputting through an output terminal. The multiphase control system comprises a plurality of control units connected in series to form a loop. Each of the control units receives a sequential input signal from an adjacent control unit connected there before through a multiphase input terminal, and generates a control signal to control power transmission from the input power source to the output terminal when determining that the output voltage is lower than a predetermined voltage value, and generates a sequential output signal at a multiphase output terminal for outputting to an adjacent control unit connected there after.

Abstract: A programmable on-time period of a DC to DC buck converting controller is adjusted according to a level of a preset output voltage or a reference signal. Therefore, the DC to DC buck converting controller of the present invention is suitable for any applications with different requests of output voltages or different operating mode.

Abstract: The present invention provides a transistor circuit with protecting function. The transistor circuit includes a transistor, a voltage detecting unit, a current detecting unit, a temperature detecting unit, and a protecting unit. The voltage detecting unit detects a voltage drop of the transistor and generates an over-voltage protection signal. The current detecting signal detects a current flowing through the transistor and generates an over-current protection signal. The temperature detecting unit detects a temperature of the transistor circuit and generates an over-temperature protection signal. The protecting unit is coupled to the control terminal to control a state of the transistor according to the over-voltage protection signal, the over-current protection signal, and the over-temperature protection signal to reduce the voltage difference between the control terminal and the second terminal, such that the voltage drop of the transistor is decreased or decreased to zero.

Abstract: The present invention provides a feedback control circuit and an LED driving circuit for using the same, wherein the feedback control circuit receives a dimming signal. The dimming signal is changed between a first state and a second state. When being in the first state, the feedback control circuit controls a converter circuit to drive the LED module for lighting stably. When being in the second state, the feedback control circuit controls the converter circuit to maintain the power conversion of the converter circuit to have an output voltage outputted by the converter circuit maintained at a level close to a lighting threshold voltage of the LED module.

Abstract: A control circuit adapted to control a power converting circuit for stabilizing an output of the power converting circuit is provided. The control circuit includes a capacitor, a charging unit, a discharging unit, a feedback control unit, and a duty-cycle adjusting unit. The charging unit has a first current source coupled to the capacitor for charging the capacitor. The discharging unit is coupled to the capacitor for discharging the capacitor. The feedback control unit controls the charging unit to charge the capacitor according to a feedback signal which represents the output of the power converting circuit. The duty-cycle adjusting unit generates a control signal and adjusts a duty cycle of the control signal according to a voltage of the capacitor.

Abstract: A power converting controller and an LED driving circuit are provided. The power converting controller controls a converting circuit, which converts an input power source into an appropriate power source to drive a load. The power converting controller includes a feedback control unit, an open-circuit judging unit and a protection unit. The feedback control unit controls the converting circuit according to a feedback signal representing the status of the load. As the open-circuit judging unit has judged that the load is continuously in an open-circuit status for a predetermined time length, the open-circuit judging unit generates an open-circuit protection signal. The protection unit is coupled to the feedback control unit and the open-circuit judging unit so as to generate a protection signal as receiving the open-circuit protection signal and thereby the feedback control unit enters a latch status to stop controlling the converting circuit.