Abstract: A light-emitting diode (LED) backlight modulation method based on duty cycle reference point setting is provided, and the LED backlight modulation method is applied to an LED backlight control circuit with row and column scan lines. Different duty cycle reference points are set for the LED string channels in the LED backlight control circuit in row-column scanning mode, whereby the LED string channels can be turned on or off at different time points during a turn-on duration of the row scan line to achieve lighting in the duty cycle, so as to realize the staggered setting of the turn-on time point and turn-off time point of each channel and avoid the need for large current jump at a power drive terminal.

Abstract: A light-emitting diode (LED) dimming driving device includes a digital-to-analog converter (DAC) control signal generating unit and an LED driving signal generating unit. The DAC control signal generating unit generates a first control signal and a second control signal. The first control signal is input to the LED driving signal generating unit to generate a first driving current I1, and the second control signal is input to the LED driving signal generating unit to generate a second driving current I2. The first driving current I1 is less than a maximum power current value Ipeak corresponding to a peak power of the LED driving signal generating unit, and the second driving current I2 is greater than the maximum power current value Ipeak corresponding to the peak power of the LED driving signal generating unit.

Abstract: A backlight LED driver circuit with current regulating function is provided. The backlight LED driver circuit includes: a LED light-emitting element, a first transistor, a first amplifier, a current regulator module, and a voltage regulator module; the current regulator module including a plurality of current channels, each including one second transistor and one third transistor; the voltage regulator module including a fourth transistor, a fifth transistor, and a sixth transistor; the fourth transistor, the fifth transistor, and the sixth transistor in the voltage regulator module and the second transistor and one third transistor of each of the current channels in the current regulator module constitute a current mirror; and the current regulator module further including a decoder configured to generate a signal for controlling on and off states of the plurality of second transistors in the plurality of current channels in response to an input digital control signal.

Abstract: A backlight LED driver circuit with current regulating function is provided. The backlight LED driver circuit includes: a LED light-emitting element, a first transistor, a first amplifier, a current regulator module, and a voltage regulator module; the current regulator module including a plurality of current channels, each including one second transistor and one third transistor; the voltage regulator module including a fourth transistor, a fifth transistor, and a sixth transistor; the fourth transistor, the fifth transistor, and the sixth transistor in the voltage regulator module and the second transistor and one third transistor of each of the current channels in the current regulator module constitute a current mirror; and the current regulator module further including a decoder configured to generate a signal for controlling on and off states of the plurality of second transistors in the plurality of current channels in response to an input digital control signal.

Abstract: A light-emitting diode (LED) dimming driving device includes a digital-to-analog converter (DAC) control signal generating unit and an LED driving signal generating unit. The DAC control signal generating unit generates a first control signal and a second control signal. The first control signal is input to the LED driving signal generating unit to generate a first driving current I1, and the second control signal is input to the LED driving signal generating unit to generate a second driving current I2. The first driving current I1 is less than a maximum power current value Ipeak corresponding to a peak power of the LED driving signal generating unit, and the second driving current I2 is greater than the maximum power current value Ipeak corresponding to the peak power of the LED driving signal generating unit.

Abstract: A light-emitting diode (LED) backlight modulation method based on duty cycle reference point setting is provided, and the LED backlight modulation method is applied to an LED backlight control circuit with row and column scan lines. Different duty cycle reference points are set for the LED string channels in the LED backlight control circuit in row-column scanning mode, whereby the LED string channels can be turned on or off at different time points during a turn-on duration of the row scan line to achieve lighting in the duty cycle, so as to realize the staggered setting of the turn-on time point and turn-off time point of each channel and avoid the need for large current jump at a power drive terminal.

Abstract: The present disclosure relates to an apparatus and method for driving a switch, such as a power switch. A driver comprises a voltage sensor to sense a drive voltage, and an electrical source to provide a drive signal having a drive value. The driver is adapted to adjust the drive value based on the drive voltage to limit a switch-current flowing through the switch.

Abstract: This specification relates to a method and a system for detecting light emitting diode (LED) short circuit in a plurality of LED strings or detecting matching among the plurality of LED strings, wherein one end of each of the plurality of LED strings is connected to a same output end of a power supply, and the other end is respectively connected to a corresponding switch. According to the present invention, first current of each of LED strings is obtained when the output end of the power supply outputs a first voltage; differences between the minimum of the first currents of LED strings and other first currents are calculated; the differences are compared with a comparing threshold; it is determined that the LED strings corresponding to the other currents for which differences are larger than the comparing threshold include short circuit or mismatch with the LED string corresponding to the minimum current. Accordingly, it is possible to reduce the number of pins and area of a control chip.

Abstract: The present disclosure relates to an apparatus and method for driving a switch, such as a power switch. A driver comprises a voltage sensor to sense a drive voltage, and an electrical source to provide a drive signal having a drive value. The driver is adapted to adjust the drive value based on the drive voltage to limit a switch-current flowing through the switch.

Abstract: An data transmission method is provided for transmitting analog data through an isolating device using a calibration input pulse and a data input pulse. The analog data may represent, for example, the desired dimming value for a flyback converter powering a solid state lighting system.

Abstract: An data transmission method is provided for transmitting analog data through an isolating device using a calibration input pulse and a data input pulse. The analog data may represent, for example, the desired dimming value for a flyback converter powering a solid state lighting system.

Abstract: This specification relates to a method and a system for detecting light emitting diode (LED) short circuit in a plurality of LED strings or detecting matching among the plurality of LED strings, wherein one end of each of the plurality of LED strings is connected to a same output end of a power supply, and the other end is respectively connected to a corresponding switch. According to the present invention, first current of each of LED strings is obtained when the output end of the power supply outputs a first voltage; differences between the minimum of the first currents of LED strings and other first currents are calculated; the differences are compared with a comparing threshold; it is determined that the LED strings corresponding to the other currents for which differences are larger than the comparing threshold include short circuit or mismatch with the LED string corresponding to the minimum current. Accordingly, it is possible to reduce the number of pins and area of a control chip.

Abstract: This specification relates to a method and a system for detecting light emitting diode (LED) short circuit in a plurality of LED strings or detecting matching among the plurality of LED strings, wherein one end of each of the plurality of LED strings is connected to a same output end of a power supply, and the other end is respectively connected to a corresponding switch. According to the present invention, first current of each of LED strings is obtained when the output end of the power supply outputs a first voltage; differences between the minimum of the first currents of LED strings and other first currents are calculated; the differences are compared with a comparing threshold; it is determined that the LED strings corresponding to the other currents for which differences are larger than the comparing threshold include short circuit or mismatch with the LED string corresponding to the minimum current. Accordingly, it is possible to reduce the number of pins and area of a control chip.

Abstract: This specification relates to a method and a system for detecting light emitting diode (LED) short circuit in a plurality of LED strings or detecting matching among the plurality of LED strings, wherein one end of each of the plurality of LED strings is connected to a same output end of a power supply, and the other end is respectively connected to a corresponding switch. According to the present invention, first current of each of LED strings is obtained when the output end of the power supply outputs a first voltage; differences between the minimum of the first currents of LED strings and other first currents are calculated; the differences are compared with a comparing threshold; it is determined that the LED strings corresponding to the other currents for which differences are larger than the comparing threshold include short circuit or mismatch with the LED string corresponding to the minimum current. Accordingly, it is possible to reduce the number of pins and area of a control chip.