LIN 2.x and SAE J2602 compliant, the single-channel MLX81112 and dual-channel MLX81115 provide a low-BOM solution to driving LEDs via constant current sources. High levels of integration mean that designers can rationalize LIN RGB module designs by combining a single mixed-signal chip with fewer than half the passive components of alternative solutions, on a single-sided PCB.
Both of the new ICs are built around a 16-bit microcontroller featuring 32 kB of Flash memory with error correcting code. Additional memory resource is provided by a 16 kByte ROM (which contains the necessary RGB mix algorithms and LIN driver), a 2 kByte RAM and a 380 Byte EEPROM. Other on-board functionality comprises a 10-bit analogue-to-digital converter (with integrated pre-divider), a LIN protocol controller, a LIN transceiver, four configurable constant current outputs and four 16-bit PWM outputs. A 24 MHz RC-based clock oscillator ensures accurate timing while a voltage regulator is provided for power management.
Melexis RGB slave controllers ensure consistent ambient lighting performance across variations in voltage, temperature and LED characteristics. Each device exhibits robust EMC/ESD characteristics, can accommodate a wide voltage input range (from 6V to 18V) and draws very little standby current (20 μA typically). Operational temperature range is from -40°C to 125°C with over-temperature shutdown and load dump protection. Temperature and battery monitoring capabilities are also provided. The MLX81112 is supplied in 8-pin SOIC package, while the MLX81115 comes in a 12-pin DFN package.