Abstract: A backlight inverter for an LCD panel of an asynchronous pulse width modulation (PWM) driving type which is capable of driving a plurality of cold cathode fluorescent lamps (CCFLs) in pairs and controlling a plurality of PWM drive signals for respective operations of the lamps to make the phases thereof different. The backlight inverter comprises a main driving integrated circuit (IC), at least one sub-driving IC, and a plurality of lamp operating circuits for operating the pairs of lamps in response to the first and second PWM drive signals and the third and fourth PWM drive signals, respectively. The lamps have different PWM on/off periods so that overshoot of a power supply circuit can be reduced so as to keep the entire system power stable.

Abstract: A backlight inverter for an LCD panel of an asynchronous pulse width modulation (PWM) driving type which is capable of driving a plurality of cold cathode fluorescent lamps (CCFLs) in pairs and controlling a plurality of PWM drive signals for respective operations of the lamps to make the phases thereof different.

Abstract: A backlight inverter for an LCD panel which is capable of detecting a fault in a transformer device including two transformers driven in tandem or an open-lamp condition and performing a control operation to stop its operation upon detecting the fault in the transformer device or the open-lamp condition. The inverter supplies a PWM signal through a switch in normal operation. The inverter also detects a voltage corresponding to current flowing through each lamp in a lamp device and determines from the detected voltage whether the open-lamp condition has occurred. The inverter further detects a voltage at a midpoint of secondary windings of the transformer pair in the transformer device and determines from the detected voltage whether the fault exists in the transformer device. In the event of the open-lamp condition or the fault in the transformer device, the inverter turns off the switch.

Abstract: Disclosed is about a single stage converter in an LCD backlight inverter which is embodied into an integrated circuit and has an individual circuit structure for converting DC current into AC current. The single stage converter in the LCD backlight inverter of the invention is embodied as an ASIC to realize an individual application circuit, replaces conventional two-stage articles to reduce the size, enhances the efficiency and reduces the part number thereby saving the cost for materials.

Abstract: An LCD backlight inverter has a buck switch for determining power supply to a DC/AC converter for converting voltage, the buck switch being connected between a supply voltage input terminal and the DC/AC converter. An overvoltage protection circuit is connected to an input terminal of said DC/AC converter for dividing voltage while providing a current path at the time of the initial drive. A first comparing block compares the dimension of a feedback signal with the dimension of a first reference voltage, the feedback signal representing the voltage according to an on/off status of the backlight. A second comparing block compares the dimension of the voltage divided in the overvoltage protection circuit with the dimension of a second reference voltage. A switching controlling block receives comparison signals from the first and second comparing blocks for controlling an on/off status of the buck switch according to the comparison signals.

Abstract: Disclosed is about a single stage converter in an LCD backlight inverter which is embodied into an integrated circuit and has an individual circuit structure for converting DC current into AC current. The single stage converter in the LCD backlight inverter of the invention is embodied as an ASIC to realize an individual application circuit, replaces conventional two-stage articles to reduce the size, enhances the efficiency and reduces the part number thereby saving the cost for materials.

Abstract: An inverter for LCD backlight operates an analog dimming control, a PWM dimming control or a complex dimming control by a control signal set by a manufacturer, and in case of the complex dimming control, realizes an original circuit operated by a controlling method distinguished from the conventional controlling method to enhance responsive characteristics when shifting a dimming mode.

Abstract: Disclosed is an inverter for LCD backlight.

Abstract: It is disclosed about a LCD backlight inverter for controlling the overvoltage with a stable output in respect to the fluctuation of an input voltage and preventing an effect to a feedback controlling block in opening a lamp used as a backlight. An overvoltage protection circuit of the LCD backlight inverter comprises a first comparing block for comparing the dimension of a feedback signal with the dimension of a first reference voltage, wherein the feedback signal detects the dimension of the voltage according to on/off status of the backlight lamp in the rear end; a second comparing block for comparing the dimension of the voltage divided in the overvoltage protection circuit with the dimension of a second reference voltage; and a switching controlling block for receiving output signals from the first and second comparing blocks and controlling on/off status of the buck switch according to corresponding comparison signals.

Abstract: A charge pump circuit for charging/pumping charge into/out of a charge pumping capacitor. Charge is pumped from the capacitor to turn on one of a pair of MOSFET transistors formed in an integrated circuit for driving a load. The MOSFET transistors are connected at a node in series with one another. The charging capacitor has one end connected at the node and the other connected through a diode to one side of a power supply which is also applied across both transistors. An input signal turns the MOSFETs on and off in a complementary fashion. Each MOSFET has a gate which is discharged to ground when the MOSFET is turned off. A zener diode prevents the capacitor from pumping excess charge to the gate of the MOSFET to which it is connected. Another zener diode prevents damage resulting from excessive voltage external to the integrated circuit.

Abstract: A motor control circuit comprises a current command circuit generates a current command signal proportional to a selected motor speed. A comparator generates a comparator output signal proportional to the difference between the current command signal and a signal proportional to current flow in the motor. An output terminal of the comparator is operatively connected to a logic circuit which generates a control signal having a duty cycle that varies proportional to the comparator output signal. A drive circuit has an input terminal to which the control signal is applied and an output terminal connected to the motor. The drive circuit generates a motor drive signal proportional to the control signal for driving said motor. A current command control circuit has an input terminal to which the current control signal is applied and an output terminal to which the current command signal is applied.