Patent ID: 8319442

Claim:
An LED array control circuit with voltage adjustment function, for controlling an LED array which includes multiple LED strings, each LED string having multiple LED devices connected in series; each LED string having a first end and a second end, and all the first ends being coupled to a common node, the LED array control circuit comprising: a first power supply circuit coupled to the common node for providing a supply voltage to the LED array; and an LED driver circuit for controlling current through each LED string, the LED driver circuit including: multiple current sources corresponding to the multiple LED strings respectively, each current source controlling an absolute value of a current through a corresponding LED string, and each current source having a first end and a second end, wherein the first end of each current source is coupled to the second end of a corresponding LED string; and a voltage adjustment circuit for adjusting a voltage of the second end of a corresponding current source according to a signal indicating a voltage drop across the corresponding LED string, such that when the supply voltage to the common node is a positive voltage, the voltage of the second end of the corresponding current source is switchable at least between a predetermined voltage and a negative voltage, and when the supply voltage to the common node is a negative voltage, the voltage of the second end of the corresponding current source is switchable at least between a predetermined voltage and a positive voltage.