Abstract: The present invention provides a current driver for driving a current driven device. The current driver includes a driving circuit, configured to generate a driving current to drive the current driven device, and conduct or cut off a driving current path through which the driving current flows according to a voltage level of a driving control node, and an accelerating circuit, coupled to the driving control node of the driving circuit, configured to provide an accelerating current flowing through the driving control node to accelerate a voltage level transition at the driving control node during an activation period of the driving circuit, and automatically cut off the accelerating current when a voltage level of the driving control node reaches a specific level.

Abstract: A light emitting diode (LED) driving apparatus is disclosed. The LED driving apparatus includes a power converter, a voltage sample-and-hold and comparison circuit, and a pre-charge clock generator. The power converter has a power transistor switch for processing power conversion and outputs a driving voltage at an output terminal. The voltage sample-and-hold and comparison circuit enters a sample-and-hold mode or a comparing mode according to a dimming status signal. The voltage sample-and-hold and comparison circuit samples and holds a feedback voltage to obtain a pre-storage voltage during the sample-and-hold mode and compares the pre-storage voltage with the feedback voltage to obtain a comparison result during the comparing mode. The voltage sample-and-hold and comparison circuit generates a pre-charge enable signal according to the comparison result.

Abstract: A driving method of a light-emitting diode (LED) adapted to a driving apparatus is provided. The driving method includes receiving a dimming signal, detecting whether the driving apparatus performs dimming, and if the driving apparatus performs dimming, determining whether a duty cycle of the dimming signal is smaller than a predetermined value. When the duty cycle of the dimming signal is not smaller than the predetermined value, respective current magnitudes of a plurality of driving currents are regulated according to the dimming signal, and each of the driving currents is output for a full time of a period. Conversely, when the duty cycle of the dimming signal is smaller than the predetermined value, each of the driving currents is output for a partial time of a period. A driving apparatus employing the driving method is also provided.

Abstract: A control method capable of preventing flicker effect for a light source module includes detecting variation situations of a driving current passing through the light source module to generate a current detection signal, adjusting a variable reference voltage according to the current detection signal, obtaining a feedback voltage from the light source module, generating a voltage control signal according to the feedback voltage and the variable reference voltage, and generating an output voltage according to the voltage control signal to drive the light source module.

Abstract: A driving apparatus of a light emitting diode (LED) and a driving method thereof are provided. In the driving method, when the driving apparatus performs dimming and a duty cycle of a dimming signal is smaller than a predetermination value, outputting time of driving currents are equally allotted in a period, and a magnitude of each driving current is regulated correspondingly. When the driving apparatus performs dimming and the duty cycle of the dimming signal is equal to or greater than the predetermination value, the driving currents are simultaneously output in the period, and the magnitude of each driving current is regulated according to the dimming signal. Therefore, an audio noise and an electromagnetic interference caused by excessive variation of a sum of the driving currents are suppressed.

Abstract: A circuit for generating reference voltage and reference current includes a band-gap reference circuit and a voltage-to-current converting circuit. The band-gap reference circuit is configured to generate a temperature-independent reference voltage by generating a first current with a positive temperature coefficient. The voltage-to-current converting circuit is coupled to a node of the band-gap reference circuit and configured to convert a voltage with a negative temperature coefficient at the node into a second current with a negative temperature coefficient. The band-gap reference circuit and the voltage-to-current converting circuit share a common current source having a feedback transistor through which a reference current flows. The reference current is divided into the first current of the band-gap reference circuit and the second current of the voltage-to-current converting circuit, thus having a temperature coefficient substantially equal to zero by combining the first current and the second current.

Abstract: A light source driving device for driving a light emitting component is disclosed. The light source driving device includes a voltage converter coupled to the light emitting component for converting an input voltage into an output driving voltage according to a voltage control signal, a dimming unit coupled to the light emitting component for implementing a dimming process according to a dimming signal, a current source coupled to the dimming unit for providing a driving current to drive the light emitting component, and a control unit coupled to the dimming unit and the voltage converter for detecting a dimming state to generate a dimming detection signal and generating a reference voltage according to the dimming detection signal, wherein the control unit controls the voltage converter to generate the output driving voltage so as to driving the light emitting component.

Abstract: An oscillator circuit including a charge/discharge unit, a capacitance amplifier, and a level detection circuit is provided. The charge/discharge unit is used to receive a control signal, and perform a charge or discharge operation on a charge/discharge terminal according to the control signal. The capacitance amplifier, including a first impedance, a second impedance, a voltage follower, and a capacitor, is capable of providing an equivalent capacitance with amplifying characteristics. An input terminal of the level detection circuit is electrically connected to the charge/discharge terminal of the charge/discharge unit, and the level detection circuit generates the control signal to the charge/discharge unit according to the charge/discharge terminal of the charge/discharge unit. The oscillator circuit of the present invention may use a capacitance with a smaller level to provide an equivalent capacitance with amplifying characteristics, and thus achieve an oscillator function.

Abstract: Provided is a light emitting diode (LED) driving circuit for driving a plurality of LED groups. The LED driving circuit includes: a voltage converter, for converting an input voltage into an output voltage, the output voltage coupled to a respective first terminal of each of the LED groups; and a controller, coupled to the voltage converter for controlling the voltage converter, the controller including a plurality of output channel terminals respectively corresponding to a plurality of output channels, one or more of the output channels are enabled and one or more of the output channels are disabled. One or more of the output channel terminals corresponding to the one or more enabled output channels are coupled to second terminals of corresponding ones of the LED groups, and one or more of the output channel terminals corresponding to the one or more disabled output channels are coupled to a reference voltage.

Abstract: At the driving initiation, whether the output channels are enabled or disabled is determined by judging whether the voltages of the output channels are changed by a charging or discharging operation. The current output sources corresponding to the disabled output channels are turned off for power-saving. In the voltage conversion, the status of the disabled output channels is ignored, for accurately control of the voltage conversion.

Abstract: A frequency generator is used for generating a frequency within a frequency range. The frequency generator includes a variable current source, a voltage drop generation unit, a voltage source, a detection unit, a conversion unit, and an oscillating circuit. The variable current source is used for outputting a current according to a control signal. The voltage drop generation unit is used for generating a voltage drop according to the current. The voltage source is used for outputting a voltage range. The detection unit is used for outputting the control signal to the variable current source according to a relationship between the voltage drop and the voltage range. The conversion unit is used for outputting a digital code according to the relationship between the voltage drop and the voltage range. The oscillator circuit is used for generating the frequency according to the digital code.

Abstract: A driving apparatus of a light emitting diode (LED) and a driving method thereof are provided. In the driving method, when the driving apparatus performs dimming and a duty cycle of a dimming signal is smaller than a predetermination value, outputting time of driving currents are equally allotted in a period, and a magnitude of each driving current is regulated correspondingly. When the driving apparatus performs dimming and the duty cycle of the dimming signal is equal to or greater than the predetermination value, the driving currents are simultaneously output in the period, and the magnitude of each driving current is regulated according to the dimming signal. Therefore, an audio noise and an electromagnetic interference caused by excessive variation of a sum of the driving currents are suppressed.

Abstract: An LED device with simultaneous open and short detection function includes a plurality of LED strings, a voltage converter, a current driving unit, a loop control unit, an open detector, a short detector and a voltage detector. The open detector and the short detector are utilized for detecting LED open and LED short for the plurality of LED strings, respectively. The voltage detector is coupled to the open detector, the short detector and the voltage converter, and is utilized for generating a reset signal to the short detector according to an output voltage of the voltage converter when the LED open occurs on the plurality of LED strings, so as to initiate the LED short detection for the plurality of LED strings again.

Abstract: A light-emitting diode (LED) device capable of dynamically regulating output voltage is disclosed. The LED device includes a plurality of LED chains, a voltage converter, a current driving unit, a loop control unit. The loop control unit is coupled to the LED chains and the voltage converter, and includes a voltage selection unit, an error amplifier, and a conversion controller. The voltage selection unit is utilized for generating a plurality of candidate voltages according to a threshold voltage and a plurality of headroom voltage voltages corresponding to the LED chains and the current driving unit, and selecting a feedback voltage from the candidate voltages. The error amplifier generates an error voltage signal according to a reference voltage and the feedback voltage. The conversion controller generates a voltage control signal according to the error voltage signal to control the voltage conversion of the voltage converter.

Abstract: A control method capable of preventing flicker effect for a light source module includes detecting variation situations of a driving current passing through the light source module to generate a current detection signal, adjusting a variable reference voltage according to the current detection signal, obtaining a feedback voltage from the light source module, generating a voltage control signal according to the feedback voltage and the variable reference voltage, and generating an output voltage according to the voltage control signal to drive the light source module.

Abstract: A light emitting diode module having a plurality of LED strings is provided. The light emitting diode module includes a voltage generating loop, a light tuner, a voltage selector, and a voltage storage and comparison circuit. The voltage generating loop generates a system voltage according to a pulse modulation control signal. The light tuner receives a light tuning signal and turns on or off the LED strings accordingly. The voltage selector selects one of terminal voltages of terminals of the LED strings coupled to the light tuner for generating a selection voltage. The voltage storage and comparison circuit generates an error voltage by comparing the selection voltage and a reference voltage. The voltage storage and comparison circuit stores the error voltage temporarily and provides the temporarily stored error voltage as the pulse modulation control signal.

Abstract: A light source driving device for driving a light emitting component is disclosed. The light source driving device includes a voltage converter coupled to the light emitting component for converting an input voltage into an output driving voltage according to a voltage control signal, a dimming unit coupled to the light emitting component for implementing a dimming process according to a dimming signal, a current source coupled to the dimming unit for providing a driving current to drive the light emitting component, and a control unit coupled to the dimming unit and the voltage converter for detecting a dimming state to generate a dimming detection signal and generating a reference voltage according to the dimming detection signal, wherein the control unit controls the voltage converter to generate the output driving voltage so as to driving the light emitting component.

Abstract: A light-emitting diode (LED) device for preventing soft-start flicker includes an LED module, a voltage converter, a variable current load and a loop control unit. The loop control unit is coupled to the LED module, the voltage converter and the variable current load, and includes a soft-start unit and a dimming control unit. The soft-start unit is utilized for activating a soft-start mechanism of the voltage converter when power of the LED device is turned on. The dimming control unit is utilized for controlling the variable current load to progressively increase a load current of the LED module to a target value and to maintain the load current on the target value until the soft-start mechanism is completed, so as to perform dimming control on the LED module.

Abstract: A signal generator and a method thereof for generating signals are provided. The signal generator includes a pulse width signal generation module and a signal generating module. The pulse width signal generation module generates a first pulse width signal according to a first pulse signal and a second pulse signal. A first signal with a first duty ratio is generated by the signal generating module based on the first pulse width signal. The first duty ratio is equal to a product of a duty ratio of the first pulse signal and a duty ratio of the second pulse signal.

Abstract: An oscillator circuit including a charge/discharge unit, a capacitance amplifier, and a level detection circuit is provided. The charge/discharge unit is used to receive a control signal, and perform a charge or discharge operation on a charge/discharge terminal according to the control signal. The capacitance amplifier, including a first impedance, a second impedance, a voltage follower, and a capacitor, is capable of providing an equivalent capacitance with amplifying characteristics. An input terminal of the level detection circuit is electrically connected to the charge/discharge terminal of the charge/discharge unit, and the level detection circuit generates the control signal to the charge/discharge unit according to the charge/discharge terminal of the charge/discharge unit. The oscillator circuit of the present invention may use a capacitance with a smaller level to provide an equivalent capacitance with amplifying characteristics, and thus achieve an oscillator function.