摘要 |
The driver circuit (10) includes a string of LEDs divided into n groups and the n groups of LEDs is electrically connected to each other in series, where a downstream end of group m-1 is electrically connected to the upstream end of group m. The driver circuit (10) also includes a power source coupled to an upstream end of group 1 and provides an input voltage. The driver circuit (10) further includes current regulating circuits, where each of the current regulating circuits is coupled to the downstream end of the corresponding group at one end and coupled to a ground at the other end. Each of the current regulating circuits includes a sensor amplifier and a cascode having first and second transistors. The driver circuit (10) also includes detectors, where each of the detectors detects a source voltage of the first transistor. |