Reconfigurable LIN switch slave eases communication of switch modules and I/O extensions

Melexis extends its family of smart LIN slave IC's with a new reconfigurable LIN switch slave. The LIN bus standard, and it’s SAE version, J2602, experience rapid growth in automotive networking due to the cost effective and robust nature of the protocol and its compatibility to CAN bus. The MLX80105 connects any door, roof, seat, steering wheel, dashboard, HVAC, light control or similar switch module requiring access via LIN.

The integration of LIN physical layer, voltage regulator, and integrated application I/O’s in the switch result in a reduction in component cost. The integration of LIN controller and approved LIN driver ease switch module LIN compatibility.

Incorporating the Melexis LIN transceiver physical layer, Melexis LIN ASSPs guarantee integrated ESD protection. The LIN protocol handler meets all LIN standards like LIN2.0, LIN2.1, as well as SAE J2602.  

The MLX80105 is a fully integrated LIN slave on a single chip. All of the necessary components: Physical layer LIN transceiver, LIN controller, voltage regulator, and application controller are integrated along with the supporting functions ADC, PWM generation, and high voltage capable I/Os. This integration level reduces the bill of materials significantly and enables the development of very compact LIN slave modules.

The established Melexis dual task microcontroller implementation (an already approved LIN driver) is used allowing the application development to be completely decoupled from the LIN network load considerations. Application software tasks are taken up by a 16-bit RISC microcontroller.

A complete C-based development environment is provided. Software development in an IDE along with low level LIN driver and software library functions are re-used from the MLX80104 uniROM IC. New customers will find an eased path for application development and deployment, and current MLX80104 customers can include the MLX80105 into existing or new projects.

The MLX80105 draws less than 50 μA of current in sleep mode and it is wake-up capable via the LIN bus as well as via connected switches or other wake-up sources. The LIN slave supports switches in matrix as well as single switch configurations connected to the 18 available I/Os. All I/Os are high voltage resistant for safely supporting remote off module connections. Eight interrupt capable I/Os support rotary encoders.

Position monitoring and control for control dials and knobs, motors or actuators is simplified with added utility of having direct physical input or software control and signal sharing among different systems. Analog inputs can convert any analog signal, like resistive encoders and resistive switches, to bus messages for use by network connected devices. An internal battery monitor enables supply voltage dependent functions.

To illuminate the switch module panel, eight open drain PWM outputs are available with configurable PWM base frequency from 45 Hz to 45 kHz. With a message from the LIN master, the LED output intensity can be adjusted according to OEM specific requirements.   

All the above functions are implemented on one piece of silicon in a 5x5 mm QFN package. This, together with a minimum of external components, enables LIN slave applications in compact PCB spaces.

“The MLX80105,” said Michael Bender, LIN product line manager at Melexis, "from an application point of view, incorporates state of the art application expertise with maximum configurability into a miniature 5 by 5mm package.  The integrated function gives all needed design freedom, while minimizing design time and qualification effort.”

Availability
Samples are available today.

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