Patent ID: 6737814
Filing Date: 2004-05-18
Classification: H01L,H05B,Y10S

Abstract:
A circuit for voltage-controlled dimming of light emitting diodes, comprising:first and second groups of series-connected light emitting diodes connected between an input port and an output port; and a switching diode connected in series between the first and second light emitting diode groups with a common forward bias orientation; a shunt resistor connected in parallel with both the first and second light emitting diode groups between the input and output ports; and a series resistor connected in series with both the first and second light emitting diode groups between the input and output ports, wherein resistances for the series and shunt resistors are selected to control switching of the first and second light emitting diode groups between series-connection and parallel-connection based on a voltage applied across the input and output ports.