Motor driver cuts material costs in automotive applications

1st December 2020

Melexis

Lanna Deamer

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Melexis has announced the third generation of its popular LIN motor driver for small motors targeting automotive mechatronic applications at up to 10W, including motor-controlled flaps and valves, and small fans and pumps.

The Gen 3 MLX81330 (0.5A motor drive) and MLX81332 (1.0A motor drive) smart LIN drivers are based on high voltage SOI (Silicon On Insulator) technology to deliver high levels of robustness and function density, combining analog and digital circuitry to create true single-chip solutions that are fully compliant with the industry standard LIN 2.x/SAE J2602 and ISO 17987-4 specifications for LIN slave nodes.

Along with an integrated motor driver, they feature extensive I/O capability and a dual microcontroller architecture. One core is dedicated to communications while the second microcontroller runs the application software.

With their ‘all-in-one’ approach to LIN slave design, the MLX81330 and MLX81332 enable a reduced Bill of Materials (BoM), smaller PCB, simpler product design and faster assembly. For example, the MLX81332 interfaces directly with an ECU and can drive up to four phases of a motor, with a maximum current of 1A per phase, or two phases with a maximum current of 1.4A. This means it can drive a 2-wire DC motor, 3-wire BLDC motor or 4-wire bipolar stepper motor, using either sensored or sensorless Field-Oriented Control (FOC) algorithms.

The smart LIN drivers include 5x16-bit PWM timers, 2x16-bit timers and a 10bit ADC, along with a differential current sense amplifier and temperature sensors. Over-current, over-voltage and over-temperature detection/protection is also integrated. In addition to analog-ready I/O, they are able to interface to standard external sensors using protocols commonly used in automotive applications, such as SPI and SENT.

The integrated processing cores share a common on-chip memory architecture. The application core (MLX16-FX) has access to 32KB Flash memory with ECC, 10KB of ROM, 2KB of RAM and 512 bytes of EEPROM with ECC. The communications processor (MLX4) can access 6KB of ROM and 512 bytes of RAM.

The embedded motor controller ICs are designed for safety applications according to ASIL-B (ISO 26262).

The smart LIN drivers are provided with software that includes the LIN communication stack.