Patent ID: 7307614

Claim:
A light emitting diode (LED) driver boost converter system having a primary power source voltage and reference source voltage and comprising: pulse width modulating (PWM) means for electrically driving one or more chains of multiple chains of LEDs, said PWM means employing a first differential amplifier input having a first input connected to said decoding means and a second input, wherein said regulating means is connected to a second input of said differential amplifier and further comprises means for generating a reference current; and connected to said chains and said PWM means, decoding means for decoding logic signals representative of selecting one or more of said multiple chains; and connected to said PWM means and said decoding means, regulating means connected to a second input of said differential amplifier for regulating a reference current such that PWM output voltage for driving said chains of LEDs is automatically adjusted until current to the one or more of said multiple chains of LEDs selected is set to a desired threshold; said regulating means including means for generating a reference current, said means for generating said reference current comprising: a reference resistor; a second differential amplifier, having a first input connected to the reference voltage source, a second input for receiving a feedback signal, and an output; a first transistor having an input connected to the output of said second differential amplifier, a first output terminal connect to said second input of said second differential amplifier and to the second reference voltage source via said reference resistor, and a second output terminal; a precision current mirror, having an input and an output, wherein said input of said mirror is connected to said second output terminal of said first transistor and said output of said mirror is connected to said second input of said first differential amplifier; and a second transistor, having an input connected to said primary power source voltage, a first output terminal connected to a secondary potential voltage level, and a second output terminal connected to connected to said second input of said first differential amplifier such that said reference current is determined by the physical size of said second transistor.