LED drivers for automotive matrix/hi-beam lighting

January 10, 2017 // By Graham Prophet
Infineon aims to enable compact and cost-effective LED front light applications with its LITIX LED driver family.

LEDs in automotive front lighting enable energy savings, new light designs and applications such as matrix beam and laser high-beam; these high-power LED drivers have been designed for automotive front lights. The drivers are available within the LITIX Power Flex series and the LITIX Power series. They address flexible DC/DC driver solutions supporting LED systems of up to 50W and even above. Application setups can vary: many medium-power LEDs with string voltages of up to 55V; or few LEDs with high currents of up to 3A and more.


Both LED drivers, the LITIX Power Flex TLD5541-1QV and the LITIX Power TLD5190QV, are suited for high-power and high-current LED applications. These include for example front lighting, laser and LED headlamps. They also suit high-efficiency supplies for LED applications working on battery voltage. Furthermore, they allow cost-optimized full-LED front light applications for cars, and even for motorcycles with their space limitations in the handlebar’s headlamp.


The TLD5541-1QV is a first available member of the new multi-topology DC/DC controller family LITIX Power Flex. The synchronous H-bridge DC/DC controller is suitable for driving all high-power LED configurations with maximum system efficiency of well above 92%. This results in higher reliability and improved thermal behaviour and reduced PCB size. With spread spectrum switching frequency, the TLD5541-1QV helps reduce EMC emissions to fulfil challenging EMC requirements such as CISPR 25 class 5.


The TLD5541-1QV features seamless buck-boost regulation and fast dynamic load step behaviour. It enables cost-optimized LED headlamps with complete protection and diagnosis features. Just one TLD5541-1QV can drive two and more separately switched LED loads in one string, with up to 55V string voltage. The LED current accuracy is specified with ±3%.


The TLD5541-1QV with built-in protection features and SPI interface offers both analogue and digital (PWM) dimming. The switching frequency is adjustable in the range of 200 kHz to 700 kHz. An adjustable soft start feature limits the