Abstract: An operating circuit applied to a backlight includes at least one current control circuit, where the current control circuit includes a transistor, an operational amplifier and a switch module. The transistor has a gate, a first electrode and a second electrode, where the first electrode is coupled to a lighting element, and the second electrode is coupled to a resistor. The operational amplifier has positive and negative input terminals, and positive and negative output terminals. The switch module switches a connection relationship between the positive input terminal, the negative input terminal, the reference voltage and the second electrode of the transistor, and switches a connection relationship between the positive output terminal, the negative output terminal and the gate of the transistor to make the close loop form a negative feedback, and the current of the lighting element not influenced by an offset voltage of the operational amplifier.

Abstract: An operating circuit applied to a backlight is provided, where the backlight includes a plurality of lighting elements, and the operating circuit includes a plurality of current control circuits, a plurality of switches, a minimum voltage selector, a supply voltage generating circuit and a control unit. The current control circuits are coupled to the lighting elements via a plurality of nodes, respectively. The switches are coupled to the nodes, respectively. The minimum voltage selector is utilized for receiving at least a portion of voltages of the plurality of nodes, and selecting a minimum voltage among the received voltages. The supply voltage generating circuit is utilized for generating a supply voltage of the lighting elements according to the minimum voltage. For each of the switches, the control unit determines an on/off state of the switch by determining whether the corresponding lighting element is an open circuit or not.

Abstract: An operating circuit applied to a backlight includes at least one current control circuit, where the current control circuit includes a transistor, an operational amplifier and a switch module. The transistor has a gate, a first electrode and a second electrode, where the first electrode is coupled to a lighting element, and the second electrode is coupled to a resistor. The operational amplifier has positive and negative input terminals, and positive and negative output terminals. The switch module switches a connection relationship between the positive input terminal, the negative input terminal, the reference voltage and the second electrode of the transistor, and switches a connection relationship between the positive output terminal, the negative output terminal and the gate of the transistor to make the close loop form a negative feedback, and the current of the lighting element not influenced by an offset voltage of the operational amplifier.

Abstract: An operating circuit applied to a backlight is provided, where the backlight includes a plurality of lighting elements, and the operating circuit includes a plurality of current control circuits, a plurality of switches, a minimum voltage selector, a supply voltage generating circuit and a control unit. The current control circuits are coupled to the lighting elements via a plurality of nodes, respectively. The switches are coupled to the nodes, respectively. The minimum voltage selector is utilized for receiving at least a portion of voltages of the plurality of nodes, and selecting a minimum voltage among the received voltages. The supply voltage generating circuit is utilized for generating a supply voltage of the lighting elements according to the minimum voltage. For each of the switches, the control unit determines an on/off state of the switch by determining whether the corresponding lighting element is an open circuit or not.