A semiconductor light source includes multiple light-emitting elements coupled in series. A driving circuit receives an input voltage, and supplies a driving current to the semiconductor light source. A bypass circuit is coupled to a part of the multiple light-emitting elements. When a low-voltage state occurs, the bypass circuit is set to the enabled state, thereby bypassing the driving current. An auxiliary power supply circuit is coupled in series with the part of the multiple light-emitting elements. When an expected current does not flow through the auxiliary power supply circuit after the bypass circuit is set to the disabled state, a judgement unit judges that an open-circuit fault has occurred in the part of the multiple light-emitting elements.

The present disclosure is for a light-emitting diode light string control system, which comprises: a switching unit having a power input end, a power output end connected to the light string, and a controlled end. A control unit is connected to the controlled end of the switching unit. A second power-generating unit is also connected to the light-emitting diode light string. The light-emitting control command sent by the control unit is in a carrier wave mode to realize brightness variation of the light string, which saves costs and simplifies the control circuit. A short-circuit protection unit is employed to provide fast and reliable response in real time.

The present disclosure is for a light-emitting diode light string control system, which comprises: a switching unit having a power input end, a power output end connected to the light string, and a controlled end. A control unit is connected to the controlled end of the switching unit. A second power-generating unit is also connected to the light-emitting diode light string. The light-emitting control command sent by the control unit is in a carrier wave mode to realize brightness variation of the light string, which saves costs and simplifies the control circuit. A short-circuit protection unit is employed to provide fast and reliable response in real time.

A smart lamp system and method for monitoring a status of LEDs. The system can provide LED status monitoring using a logic controller communicating with at least one strip of LEDs. The system can utilize the logic controller to assign a unique identifier (ID) to the at least one strip of LEDs based on a physical position of a plurality of dual-inline package (DIP) switches incorporated within a smart lamp housing. The system can provide a hardware architecture to interface the logic controller with a power-line communication (PLC) transceiver. The system can establish a communication protocol between the PLC transceiver and a PLC receiver to efficiently communicate the statuses of the LEDs. The logic controller can generate a payload including a binary representation of the unique ID of the smart lamp and the statuses of the LEDs and transmit the payload to the PLC transceiver.

A smart lamp system and method for monitoring a status of LEDs. The system can provide LED status monitoring using a logic controller communicating with at least one strip of LEDs. The system can utilize the logic controller to assign a unique identifier (ID) to the at least one strip of LEDs based on a physical position of a plurality of dual-inline package (DIP) switches incorporated within a smart lamp housing. The system can provide a hardware architecture to interface the logic controller with a power-line communication (PLC) transceiver. The system can establish a communication protocol between the PLC transceiver and a PLC receiver to efficiently communicate the statuses of the LEDs. The logic controller can generate a payload including a binary representation of the unique ID of the smart lamp and the statuses of the LEDs and transmit the payload to the PLC transceiver.

A display driver circuit for controlling a display panel having a plurality of light-emission diode (LED) strings includes a plurality of current regulators and a control circuit. Each of the plurality of current regulators is configured to control one of the plurality of LED strings. The control circuit, coupled to the plurality of current regulators, is configured to generate a plurality of pulses in a plurality of pulse width modulation (PWM) signals and output each of the plurality of PWM signals to a respective current regulator among the plurality of current regulators. Wherein, the plurality of pulses are scrambled.

A display driver circuit for controlling a display panel having a plurality of light-emission diode (LED) strings includes a plurality of current regulators and a control circuit. Each of the plurality of current regulators is configured to control one of the plurality of LED strings. The control circuit, coupled to the plurality of current regulators, is configured to generate a plurality of pulses in a plurality of pulse width modulation (PWM) signals and output each of the plurality of PWM signals to a respective current regulator among the plurality of current regulators. Wherein, the plurality of pulses are scrambled.

A minimum voltage detector circuit is disclosed. The circuit includes a plurality of LED strings each having a plurality of series-coupled LEDs. The minimum voltage detector circuit is configured to detect a minimum voltage from among the plurality of LED strings, and also to perform open/short detection among the plurality of LED strings. The minimum voltage detector circuit includes a plurality of voltage comparators and correspondingly coupled replica circuits. Each of the voltage comparators includes an amplifier having a first input coupled to a cathode of a last LED of one of the plurality of LED strings, an output, and a second input coupled to the output. Each voltage comparator further includes a replica circuit coupled to the amplifier. The replica circuit is configured to maintain an output transistor of the amplifier in an active state when the amplifier is in an unbalanced state.

A minimum voltage detector circuit is disclosed. The circuit includes a plurality of LED strings each having a plurality of series-coupled LEDs. The minimum voltage detector circuit is configured to detect a minimum voltage from among the plurality of LED strings, and also to perform open/short detection among the plurality of LED strings. The minimum voltage detector circuit includes a plurality of voltage comparators and correspondingly coupled replica circuits. Each of the voltage comparators includes an amplifier having a first input coupled to a cathode of a last LED of one of the plurality of LED strings, an output, and a second input coupled to the output. Each voltage comparator further includes a replica circuit coupled to the amplifier. The replica circuit is configured to maintain an output transistor of the amplifier in an active state when the amplifier is in an unbalanced state.

A circuit for driving a light-emitting diode (LED) load and a direct current to direct current (DC-DC) converter includes a first sampling sub-circuit, a driving circuit. The first sampling sub-circuit is configured to generate a current signal representing a load current of the LED load. The driving circuit is configured to receive a brightness adjustment signal and a frequency adjustment signal; generate a first control signal, based on the current signal and the brightness adjustment signal, for controlling an output current of the DC-DC converter; and generate a second control signal, based on the frequency adjustment signal, for controlling a switching frequency of the LED load.