Patent ID: 8629632

Claim:
A light emitting diode (LED) driver system, comprising: a driver IC, coupled to a voltage supply, the driver IC generating a base voltage and senses a collector voltage; an NPN bipolar transistor, coupled to the driver IC, the NPN bipolar transistor being driven by the collector voltage and the base voltage at a collector and a base, respectively, to generate an LED current at an emitter according to a common-collector configuration; an LED string, coupled to the NPN bipolar transistor, the LED string being biased between the emitter of the NPN bipolar transistor and the ground and driven by the LED current; and a series resistor, coupled between the voltage supply and the NPN bipolar transistor, the series resistor being arranged in series with the NPN bipolar transistor and having a preferred resistance value that at least partially controls the LED current through the NPN bipolar transistor.