To guarantee the driver’s safety at all times, OSRAM Continental’s new CELSIUS LED driver ensures continuous availability of a vehicle’s lighting systems – under all circumstances and in all situations. This is made possible by regular checks and providing the LEDs with the precise current they need.

The complexity of modern lighting systems is increasing more and more, particularly due to advanced functions such as dynamic light adaptation. Fail-safe availability of LED-based lighting solutions is therefore essential. With eight patents, CELSIUS guarantees fail-safe operation under all conditions and offers the necessary flexibility for the control units to cover a wide range of applications.

The driver monitors lighting functions such as brake lights and turn indicators. In the event of a system failure, OC’s new solution takes charge to guarantee the flow of power through the LEDs.

Three-level safety system

While most current solutions only address failing microcontrollers and not with the failure of other hardware components, CELSIUS takes measurements based on a three-level safety system, CELSIUS takes measurements on – based on a three-level safety system. With this approach, OC ensures that the system works either in full operation or at least in a fail-safe state to guarantee that the car driver and his environment are provided with continuous light in every situation, on every journey.

At the first level, CELSIUS tests the state of its own functions, its safety mechanisms and its operating infrastructure and determines the environment’s parameters from the hardware to the LED. At the second level, the software algorithms assess the parameters and start operation. Finally, at the third level, the LED driver monitors whether the software system is still functional.

Testability in operation and in production

To check the circuitry responsible for the correct current and therefore light for each operation, OC has implemented a self-test in the integrated circuit. It can be used to check the required functions such as current measurement and watchdogs as well as the mathematical unit. Test routines measure internal variables such as references and external components, for example the current shunt and the inductor.

Finally, all external components around the LED driver are analyzed.

In addition, the stored data can be verified with a checksum. Since all these functions are measured at the start of normal operation, the test results can also be used for production plants, resulting in faster test times and reduced test equipment.