Melexis MLX81119 Simplifies Automotive Lighting Design with Integrated DC/DC Control and Advanced LED Management
Melexis continues to address the growing demands of modern automotive lighting with the introduction of the MLX81119, an advanced 18-channel LED driver designed to improve efficiency, simplify system design, and support increasingly sophisticated vehicle lighting architectures.
Addressing the Challenges of Modern Automotive Lighting
Lighting has become a defining feature in today’s vehicle design, both for interior ambiance and exterior styling. Automakers are integrating more lighting elements to enable advanced functions, personalization, and stronger brand identity.
However, as electronic systems are placed deeper within vehicles, engineers face increasing constraints related to space, thermal management, and power efficiency. Traditional lighting architectures often rely on external DC/DC converters to power LEDs, which adds heat generation, increases component count, and complicates PCB layouts.
The MLX81119 addresses these limitations by integrating a 1A DC/DC converter directly into the device. The converter generates an optimized local LED supply voltage that can be programmed between 2.5V and 6V. Instead of dissipating excess voltage as heat, the device dynamically adjusts LED supply voltage according to operating conditions and color-mixing requirements, significantly reducing power loss and thermal stress. This level of optimization is difficult to achieve using conventional fixed-voltage external converter solutions.
Advanced LED Control and Thermal Compensation
The MLX81119 features 18 low-side current sources configurable up to 60 mA, along with independent 16-bit PWM control. Each device can support up to six RGB LEDs, enabling smooth color transitions and advanced lighting animations.
To maintain consistent lighting quality across the full automotive temperature range, the device includes both direct and indirect temperature sensing capabilities. These features actively compensate all channels to preserve stable color accuracy under varying operating conditions.
Built on the proven MLX81118 architecture, the MLX81119 integrates a complete LIN system, including the transceiver and protocol handler, and is fully compliant with LIN 2.x and SAE J2602 standards.
The device was developed according to ISO 26262 requirements and can support implementations up to ASIL B, depending on the system safety concept. This makes it suitable for safety-related interior and exterior automotive lighting applications.
Simplified Power Design and Compact Integration
By integrating the DC/DC converter directly into the chip, the MLX81119 greatly simplifies the external power stage. The device requires only two capacitors and one inductor to operate, eliminating the need for separate DC/DC controllers and many associated passive components.
This reduction in component count and PCB area enables more compact lighting modules and easier integration into space-constrained automotive environments.
In addition, the device can function as a LIN-controlled power and I/O expander, allowing its 18 channels to support auxiliary loads or distributed functions within the module.
Embedded Processing and Protection Features
LED control is managed through Melexis’ integrated 16-bit microcontroller architecture. The embedded memory subsystem includes 32 KB of flash memory and 4 KB of RAM for storing applications, LED calibration data, and other system information.
The compact device is housed in a 5 mm × 5 mm QFN32 package and supports an operating voltage range from 5.5V to 28V. It also includes diagnostic and protection features such as overcurrent detection, short-circuit protection, and thermal shutdown functionality.
According to Michael Bender, the MLX81119 was designed specifically to address the evolving challenges of modern automotive lighting systems. By integrating a DC/DC converter and dynamically optimizing LED supply voltage, engineers can simplify designs, improve efficiency, and scale lighting architectures without adding unnecessary complexity.