Abstract:
Embodiments of the invention provide a method and a circuit for generating a reference signal for controlling a peak current of a converter switch. According to at least one embodiment, the circuit includes a squarer configured to squire an input voltage signal divided from a primary-side supply voltage of an isolated converter, and a duty ratio calculator configured to calculate a duty ratio of energy transfer to a secondary side. The circuit further includes an operator configured to generate and output a reference signal for controlling the peak current of the converter switch from a square signal of the input voltage signal using the duty ratio of energy transfer calculated by the duty ratio calculator.
Abstract:
There is provided an integrated circuit controlling a power supply, the integrated circuit including: an HV pin obtaining startup power; a voltage dividing unit connected to the HV pin; and an input voltage detecting unit detecting an input voltage through voltage distribution by the voltage dividing unit. The integrated circuit may be capable of reducing manufacturing costs by omitting a separate voltage sensing pin.
Abstract:
There are provided a light emitting diode driving apparatus and a light emitting diode lighting apparatus capable of absorbing a noise current generated according to power of a phase control of a dimmer. The light emitting diode lighting apparatus includes: a dimmer controlling a phase of an alternating current (AC) power; a power supplying unit receiving the phase-controlled power from the dimmer and supplying a preset driving power; a driving unit receiving the driving power from the power supplying unit to drive a light emitting diode unit receiving the phase-controlled power; and a noise current absorbing unit suppressing an increase in a voltage level of the driving power supplied to the driving unit by the phase-controlled power.
Abstract:
The present invention relates to an average current controller, an average current control method and a buck converter using the average current controller. The average current controller includes a first comparator for generating a high H signal, a multivibrator for generating a TAVG pulse signal by receiving a high H signal outputted from the first comparator, a timing generator for generating a signal CH_ON to charge/discharge a capacitor by using at least the TAVG pulse signal, an integrator circuit unit for charging/discharging the capacitor, a second comparator for outputting a corresponding signal, an up/down counter for increasing or decreasing a counting value and a digital/analog converter for outputting by converting an output (digital signal) of the up/down counter into an analog signal.
Abstract:
There is provided an apparatus for driving a light emitting diode (LED), performing switching-operation with respect to a pair of LED groups by a phase difference of 180 degrees. The apparatus includes a switching unit that alternately switches a first LED unit and a second LED unit of at least one pair of LED units emitting light by receiving rectified power, in accordance with a predetermined phase difference, a current limiting unit that limits a current flowing in the at least one pair of LED units through the switching of the switching unit, and a driving control unit that controls switching driving of the switching unit in accordance with a voltage level of the rectified power.
Abstract:
A light emitting diode (LED) driving apparatus may include: a power converting unit switching input power to supply driving power to at least one LED; and a driving controlling unit controlling the supplying of the power of the power converting unit based on a switching period of the power converting unit and a demagnetization time in the switching period.
Abstract:
There is provided a light emitting diode (LED) driver including: a power supplying unit including a dimmer and a rectifying unit and supplying a supply voltage to an LED device; and a control unit acquiring section information regarding the supply voltage and setting an LED on-time based on the section information.
Abstract:
Disclosed herein is a voltage control circuit for a dimmer and a dimming method. In accordance with an embodiment, the dimming method using a voltage control circuit for a dimmer includes the steps of determining whether a current voltage value input to a constant dimming range maintainer is equal to a preset minimum or maximum voltage value or exists between the minimum and maximum voltage values, and determining whether the current voltage value is greater than the maximum voltage value when the current voltage value isn't equal to the minimum or maximum voltage value or doesn't exist between the minimum and maximum voltage values. The method further includes the steps of updating the minimum voltage value to the current voltage value when the current voltage value isn't greater than the maximum voltage value, and updating the maximum voltage value to the current voltage value when the current voltage value is greater than the maximum voltage value.
Abstract:
There is provide a light emitting diode lighting apparatus capable of being generally used in various kinds of dimmer, the apparatus including: a dimmer varying waveforms of input power according to a dimming signal; a bleeder adjusting a bleeding current under control; a controller comparing a latching current of the dimmer with the bleeding current of the bleeder to control the amount of the bleeding current; and an LED driver receiving a current other than the bleeding current flowing through the bleeder from among the currents from the dimmer to driver a light emitting diode (LED).
Abstract:
Disclosed herein are a PWM control circuit, a flyback converter, and a PWM control method. The PWM control circuit includes: a peak storing and reference signal generating unit storing a peak value of one period of a feedback signal from a secondary side output and inverting the peak signal arid outputting the inverted peak signal as a reference signal; and a PWM control signal generating unit generating a PWM control signal by using an output obtained by comparing the reference signal with a reference waveform from the peak storing and reference signal generating unit. In addition, the flyback converter including the same and the method for controlling PWM are proposed.