Light sensor closes loop on laser LED headlight drivers

July 04, 2016 // By Graham Prophet
Optimised linearity and temperature range maximizes effectiveness of Melexis’ sensor for automotive laser front lights; in response to the emergence of laser-powered automotive front lighting systems, Melexis developed the MLX75305 series of advanced light sensor ICs.

Each MLX75305 incorporates a photodiode, trans-impedance amplifier and output stage. Unlike alternative devices, it is fully AEC-Q100 qualified and supports an operational temperature range from -40°C up to +125°C. Supplied in an SOIC8 package, the MLX75305 provides engineers with a simple to implement, one chip solution for accurately monitoring headlamp output, requiring minimal external components and taking up very little board space. Covering a spectral bandwidth of 500 nm to 1000 nm, the IC maintains ±2% linearity across its whole output voltage range with a typical responsiveness of 70 mV/(µW/cm²).

Front lighting based on laser diodes*, Melexis notes, will see deployment within a growing number of high end vehicles in the near future. By using this technology substantial increases in illumination can be witnessed, thus enabling long-range sight, while at the same time lowering the power budget required. Laser-powered front lighting provides a way for car manufacturers to improve safety for road users without affecting vehicle fuel efficiency. The increased luminous flux also means that headlamps can be reduced in size - thereby enhancing the vehicle’s aesthetic and its aerodynamic properties.