Disclosed is an outage detection circuit for detecting a defective light source, such as a LED coupled to a DC-DC converter circuit for receiving a power signal. The outage detection circuit includes a top voltage detector coupled to the LED for detecting a voltage across the LED. The top voltage detector has a top voltage terminal for supplying a top voltage signal. The detection circuit further includes a differential amplifier coupled to the top voltage terminal for receiving the top voltage signal as a first input signal and coupled to a reference voltage terminal. The reference voltage terminal is configured to supply a reference voltage as a second input signal. The differential amplifier includes an output terminal for supplying an outage detection signal.