LIN Controller for RGB LEDs in the Vehicle Interior

The recently-introduced Elmos IC E521.36 enables a variable, cost-efficient and very space-saving design of RGB LED modules for the connection to a LIN bus. The device includes a powerful 16-bit microcontroller with 32 kbyte NVM, 128-byte EEPROM and a LIN transceiver that meets the requirements up to LIN 2.2.

The integrated microcontroller can be programmed with IAR's widely used software development environment. The addressing in the network takes place with the integrated BSM auto-addressing (bus shunt method).

Furthermore, the device has three current sources, each with up to 40mA and three 16-bit pwm generators. The 48MHz pwm clock ensures full 16-bit color resolution at a 732Hz repetition rate, enabling flicker-free applications and meeting all known OEM requirements.

The primary target application for the E521.36 is the ambient lighting in the vehicle interior.

For power management and temperature compensation, the IC has an integrated temperature sensor. In addition, a differential measurement of the LED voltage can be performed with the ADC and thus effective temperature compensation can be achieved.

Auto-addressing is a robust and well-proven method of addressing applications in a LIN bus system. All the necessary development and diagnostic tools are already in the field for this process. The method used is based on passive components in the LIN line and offers very good fault tolerance, e.g. at "Loss of Ground", as well as the possibility of "mixed" installation with standard LIN bus applications.

This allows bus applications who do not know the BSM procedure to be integrated into a system. Each bus application is also reachable during the addressing of the participants. Broadcasts can be sent to all applications at any time.

Through a simple software implementation in the slave, the master can make the address assignment plausible. This unique feature even allows addressing to be diagnosed.

The device is available in the SO8EP package.