Abstract: A change in the forward voltage (VF) for a string of series-connected, high-brightness LEDs (HB LEDs) can indicate deterioration or complete failure of one or more of the LEDs. Accordingly, this circuit assesses the LED's health by monitoring VF. Maxim > App Notes > Amplifier and Comparator Circuits Display Drivers LED Lighting Keywords: high-brightness LEDs, HBLEDs, forward voltage, differential measurments, LED drivers, comparators Jul 30, 2010 APPLICATION NOTE 4479 Diagnose LEDs by Monitoring the Switch-Mode Duty Cycle By:Fons Janssen, Senior Member of the Technical Staff Abstract:A change in the forward voltage (VF) for a string of series-connected, high-brightness LEDs (HB LEDs) can indicate deterioration or complete failure of one or more of the LEDs. Accordingly, this circuit assesses the LED's health by monitoring VF. A similar version of this article appeared in the April 4, 2009 issue of EDN magazine. The forward voltage (VF) of high-brightness LEDs (HB LEDs) is often monitored to assess the health of ……