A control circuit for controlling light emitting diodes comprises a switch for turning on or off a string of light emitting diodes. A combiner generates a control signal from a data signal and a noise signal. A sigma delta modulator receives the control signal and a clock signal with a clock period and...http://www.google.com.au/patents/US7768216?utm_source=gb-gplus-sharePatent US7768216 - Control circuit and method for controlling light emitting diodes
