Backlight control circuit

A backlight control circuit, comprising:

• a voltage supply circuit, under control by a control signal, for receiving an input voltage and generating an output voltage;
• a plurality of nodes for respectively indicating the current status of corresponding light emission device paths, wherein the light emission device paths are coupled to the output voltage and each node corresponds to a different one of the paths;
• and
• a high-low voltage comparison and amplifier circuit for generating the control signal according to a voltage difference between at least two of the plurality of nodes, wherein the high-low voltage comparison and amplifier circuit includes:
• a lowest voltage selection circuit electrically connected with the plurality of nodes;
• a highest voltage selection circuit electrically connected with the plurality of nodes;
• and
• a comparator circuit having inputs respectively electrically connected with the lowest voltage selection circuit and the highest voltage selection circuit.

A backlight control circuit, comprising:

• a voltage supply circuit, under control by a control signal, for receiving an input voltage and generating an output voltage;
• a plurality of nodes for respectively indicating the current status of corresponding light emission device paths, wherein the light emission device paths are coupled to the output voltage and each node corresponds to a different one of the paths;
• and
• a high-low voltage comparison and amplifier circuit for generating the control signal according to a voltage difference between at least two of the plurality of nodes, wherein the high-low voltage comparison and amplifier circuit includes:
• a plurality of comparators, each comparator having two inputs respectively electrically connected with two of the plurality of nodes;
• and
• an OR gate having inputs electrically connected with the outputs of the plurality of comparators, wherein the output of the OR gate is converted to an analog signal by one of the following circuits:
• an integrator, a low pass filter, or a charging and discharging circuit, and the converted analog signal is compared with a reference voltage to generate the control signal.

A backlight control circuit, comprising:

• a voltage supply circuit, under control by a control signal, for receiving an input voltage and generating an output voltage;
• a plurality of nodes for respectively indicating the current status of corresponding light emission device paths, wherein the light emission device paths are coupled to the output voltage and each node corresponds to a different one of the paths;
• a high-low voltage comparison and amplifier circuit for generating the control signal according to a voltage difference between at least two of the plurality of nodes, and
• at least one under current detection circuit for detecting whether at least one of the light emission device paths is in an under current condition, and when the under current condition occurs, the under current detection circuit sends an exclusion signal to exclude a corresponding node so that it is not a valid input of the high-low voltage comparison and amplifier circuit.