In increasingly dense vehicle applications, such as door panels, dashboards, and charging port lighting,
lighting has become a key element of modern automotive design. Both inside and out, original equipment manufacturers (OEMs) are increasing the number of lighting displays to support new functionalities, personalization, and brand differentiation. However, physical, efficiency, and thermal limitations are becoming more severe as more electronics are deployed inside the vehicle. In conventional architectures, supplying LEDs via external DC/DC converters increases heat generation, the number of components, and design complexity, making it difficult to meet these limitations at scale.
The 18-channel MLX81119 addresses this challenge by integrating a 1A DC/DC converter that generates an optimized, programmable local LED supply voltage between 2.5V and 6V. Instead of dissipating excess voltage as heat, the device dynamically adapts the LED supply to the active color mix and operating conditions, significantly reducing power losses and thermal stress. This level of voltage optimization is not possible with fixed external DC/DC converter solutions.
With 18 configurable low-side current sources down to 60mA and independent 16-bit PWM control, the MLX81119 supports up to six RGB LEDs per device, enabling smooth color transitions and advanced lighting animations. The built-in direct and indirect temperature sensor allows for active compensation across all channels, maintaining stable color points throughout the automotive temperature range.
Based on the proven architecture of the MLX81118, the MLX81119 integrates a complete LIN system, including a transceiver and protocol driver, fully compliant with LIN 2.x and SAE J2602. Developed in accordance with ISO 26262, the device supports implementations up to ASIL B depending on the system's safety concept, making it suitable for functionally relevant indoor and outdoor lighting applications.
The integrated DC/DC converter dramatically simplifies the external power stage. The MLX81119 operates with just two capacitors and a single induction coil, eliminating the need for a separate DC/DC driver and its associated passive components. This reduction in component number and PCB footprint enables more compact lighting modules and facilitates integration in space-constrained environments. In addition, the device can be configured as a LIN-controlled power and I/O extension, using its 18 channels to support auxiliary loads or distributed functions within a module.
The LEDs are controlled by a 16-bit Melexis microcontroller. The integrated memory subsystem includes 32 KB of Flash and 4 KB of RAM to support the application, LED calibration coefficients, and other system data. The compact device comes in a 5 mm × 5 mm QFN32 package, operates on a 5.5 V to 28 V supply, and includes diagnostic features such as overcurrent detection, short-circuit protection, and overtemperature protection.
"With the MLX81119, we have created a solution that directly addresses the limitations faced by modern automotive lighting designs," said Michael Bender, Product Line Manager at Melexis. "By integrating the DC/DC converter and dynamically adapting the LED supply voltage, engineers can simplify their designs, improve system efficiency, and expand lighting architectures without adding complexity."
