A control circuit of a DC/DC converter is provided for supplying a driving voltage to a light emitting element. A hysteresis comparator compares a detection voltage that corresponds to the output voltage of the DC/DC converter with two threshold voltages. If the detection voltage is smaller than the...http://www.google.fr/patents/US7781988?utm_source=gb-gplus-shareBrevet US7781988 - DC/DC converter
