METHOD OF FORMING A CURRENT CONTROLLER FOR AN LED AND STRUCTURE THEREFOR

摘要

In one embodiment, an LED current controller is formed to determine which of a plurality of LED branches has the largest voltage drop and to select the current through that branch to use in controlling the value of current that flows through other LED branches.

主权项

1. A method of forming an LED current controller comprising:
forming a first current control cell to receive a first LED current from a first LED branch, the first LED branch having a first voltage drop across the first LED branch; forming a second current control cell to receive a second LED current from a second LED branch having a common connection in a pseudo-parallel configuration with the first LED branch, the second LED branch having a second voltage drop across the second LED branch; forming the LED current controller to determine a larger one of the first or second voltage drops and responsively select one of the first or second LED currents, respectively, and to form a control current that is ratioed to the one of the respective first or second LED currents; and forming the first and second current control cells to regulate another of the first and second LED currents to be ratioed to the control current.