Abstract:
A de-glitch switching converting circuit and a controller thereof are provided. In the embodiment of the invention, the circuit can filter noises with high frequency by way of time judgment, so as to avoid the erroneous operation of the controller affecting the stability of the output voltage or the output current. Compared with the method of using low-pass filters with large capacitors to filter noises, highly increasing the cost of the circuit is unnecessary in the embodiment of the invention. The circuit in the embodiment of the invention also has the capability for filtering noises with high amplitudes. In addition, by setting suitable parameters, the circuit in the embodiment of the invention can also avoid affecting the transient response of the circuit while filtering noises.
Abstract:
A multi-lamps LCD back-light control circuit comprises a control unit, an full bridge switch, a resonance network circuit, a voltage transformer, a lamp, and a feedback network. A constant operating frequency and a pulse width modulation (PWM) feedback are used to control the CCFL current. The back-light control circuit is such that a power switch of the full bridge switch outputs a duty cycle that is controlled and changed via a PWM controller of the control unit, while a ground switch of the full bridge switch outputs a constant duty cycle controllable above 50%.
Abstract:
A switching system capable of reducing the noise of the output signal is provided. The switching system includes a first switch and a second switch, wherein the first switch conducts a first signal according to a first control signal; the second switch conducts a second signal according to a second control signal. And the voltages of the first control signal and the second control signal are restricted within a voltage interval to reduce the noise produced during the switching of the switches.
Abstract:
A loading system and a controller thereof are disclosed. The controller includes an adjustable triangle wave generator, an error signal generator, and a pulse signal generator. The triangle-wave generator is adapted to perform an amplitude and frequency operation according to the reference voltage and the feedback voltage for generating an amplitude-frequency adjustable triangle wave according to a variation of the feedback voltage. The error signal generator is adapted to perform an error operation according to the feedback voltage and the reference voltage for outputting an error signal. The pulse signal generator is adapted to receive and compare the error signal and the amplitude-frequency adjustable triangle wave for outputting a pulse controlling signal for the loading system.
Abstract:
The invention provides an LED current balancing circuit, comprising a first and a second LED set coupled to a voltage source, a first transistor, and a second transistor. The first LED set comprises a first loader. The first transistor and the second transistor form a current balancing circuit for adjusting currents passing through the first and second LED sets.
Abstract:
A variable gain device having higher linearity and wider gain range is provided. The variable gain device includes a transduction unit for generating an output current, a control unit for adjusting the current gain of the gain amplifying unit according to a gain control signal, a gain amplifying unit receiving the current signal and generating a gain adjustable current according to the current gain of the control unit, an output DC level control unit controlling the DC level of the output signal of the variable gain device, and an output unit generating an output signal according to the signals output by the output DC level control unit and the gain amplifying unit.
Abstract:
A digital to analog converter for an analog Liquid Crystal Display (LCD) includes a digital inlet, a latching circuitry, a voltage level shifter circuitry, a switching circuitry, and a resistance network with a resistance compensatory circuitry. The resistance network with the resistance compensatory circuitry is electrically connecting with the switching circuitry and adapted to regulate a pattern of the analog output signal so as to optimize the analog output signal. Specifically, the resistance network with a resistance compensatory circuitry is to produce the best linear conversion from the digital signal to the analog signal for use by the LCD.
Abstract:
A loading system and a controller thereof are disclosed. The controller includes an adjustable triangle wave generator, an error signal generator, and a pulse signal generator. The triangle-wave generator is adapted to perform an amplitude and frequency operation according to the reference voltage and the feedback voltage for generating an amplitude-frequency adjustable triangle wave according to a variation of the feedback voltage. The error signal generator is adapted to perform an error operation according to the feedback voltage and the reference voltage for outputting an error signal. The pulse signal generator is adapted to receive and compare the error signal and the amplitude-frequency adjustable triangle wave for outputting a pulse controlling signal for the loading system.
Abstract:
A controller for controlling at least two power circuits comprises a synchronous oscillator and a multi-phase PWM controller. The synchronous oscillator receives a timing signal for generating a synchronous control signal in which the timing signal is synchronous to a display signal. The multi-phase PWM controller receives the synchronous control signal for generating at least two PWM signals. The at least two PWM signals are coupled to the at least two power circuits for driving the at least two power circuits respectively. The at least two PWM signals are synchronous to the timing signal and with a phase shift between the at least two PWM signals.
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.