Patent ID: 7724220

Claim:
An LED current driving system, comprising: a timing controller, for providing at least one duty cycle control signal; and an LED driver, coupled to the timing controller and having at least one LED driving unit for outputting a driving current to an LED, each LED driving unit having a plurality of current sources and a plurality of switches connected thereto respectively, each switch controlling the ON/OFF state of the corresponding current source in accordance with the duty cycle control signal and a current control signal, wherein the magnitude of the current of each current source is 2 N times a reference current, where N is 0 or a positive integer, and wherein the current sources comprise a first current source, a second current source, and an (N+1) th current source, the current of the first current source is the reference current, the current of the second current source is twice the reference current, and the current of the (N+1) th current source is 2 N times the reference current.