LIN RGB LED controller simplifies automotive ambient lighting
Melexis claims that its latest LIN RGB LED controller, the MLX81113, delivers more functionality for ambient light applications and simplifies the design process.
The MLX81113 meets ISO 26262 functional-safety compliance for ASIL-A classified applications and has more on-chip memory, higher output current and increased EMC robustness compared to Melexis’ MLX81108.
The MLX81113 raises system-on-chip capabilities, featuring the MLX16 FX 16-bit RISC microcontroller with 2kbyte of RAM and 32kbyte of application usable flash memory, and system ROM for increased application performance. The on-chip EEPROM is increased to 576bytes for storing user data, such as LED calibration co-efficients to ensure uniform brightness and colour for automotive applications.
The four output current sources are software-programmable and can deliver up to 60mA, allowing the use of a wide range of RGB LEDs from different suppliers, explained Melexis. Independent PWM control, configurable up to 16-bit resolution, means any colour point and brightness level of the connected RGB LED can be adjusted. Built-in temperature monitoring ensures stable colour over the full temperature range, from -40 to +125 degrees C and permits temperature compensation for all colour channels. Any temperature drift of red colour as well as green and blue can be fully compensated.
A toolchain is also available. It includes an evaluation PCB as well as In-circuit-emulator and C-compiler package. To simplify software development, Melexis also provides essential software parts like LIN driver, colour mixing and math library as well as IC initialisation routines.
Lighting design allows for personalisation and differentiation within the vehicle cabin. This controller supports this trend, said Michael Bender, LIN product line manager at Melexis. “Our LIN-compatible RGB(W) drivers enable sophisticated yet cost-effective ambient lighting for vehicles from entry-level to mid-range and luxury models. The MLX81113 . . . .lowers the component count, thanks to the very high EMC robustness archived by using silicon-on-insulator (SOI) technology. Additionally it is designed in accordance with ISO 26262 to ease system-level functional-safety certification.”
The MLX81113 contains a complete LIN system, including transceiver and protocol handler for connecting RGB ambient modules to the vehicle’s existing LIN network. Compliant with LIN2.x and SAE J2602 standards, and supporting auto-addressing, the on-chip system enables minimal module size and bill of materials (BoM) costs.
The MLX81113 features high-voltage I/Os and can operate from a supply voltage as low as 4V, delivering superior performance even if the vehicle supply voltage fluctuates, such as during stop-start operation. Safety features include 28V jump start, and battery over-voltage and under-voltage detection.
The MLX81113 is in production now and can be supplied with PPAP in accordance with AECQ-100. It is available in a choice of SOIC8 exposed pad and leadless DFN10 3.0 x 3.0mm thermally enhanced packages for superior thermal performance.
