LIN motor driver cuts material costs in automotive mechatronic applications
An integrated single-chip LIN motor driver from Melexis is claimed to reduce the bill of materials (BoM) and simplify the design of motor-controlled flaps, valves, small fans and pumps for automotive use.
The third generation of LIN drivers for small motors targets automotive mechatronic applications at up to 10W. The 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. It combines analogue and digital circuitry for single chips that are fully compliant with the industry standard LIN 2.x/SAE J2602 and ISO 17987-4 specifications for LIN slave nodes.
Used with an integrated motor driver, they have I/O capability and a dual microcontroller architecture. One core is dedicated to communications while the second microcontroller runs the application software.
In addition to a reduced BoM, the MLX81330 and MLX81332 enable a smaller PCB, simpler product design and faster assembly, says Melexis. For example, the MLX81332 interfaces directly with an engine control unit (ECU) and can drive up to four phases of a motor, with a maximum current of 1.0A per phase, or two phases with a maximum current of 1.4A. This means it can drive a two-wire DC motor, three-wire BLDC motor or four-wire bi-polar stepper motor, using either sensored or sensorless field-oriented control (FoC) algorithms.
The smart LIN drivers include five 16-bit PWM timers, two 16-bit timers and a 10bit ADC. There is also a differential current sense amplifier and temperature sensors. Over-current, over-voltage and over-temperature detection/protection is also integrated. There is also analogue-ready I/O, 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 32kbyte flash memory with error correction code (ECC), 10kbyte of ROM, 2kbyte of RAM and 512 bytes of EEPROM with ECC. The communications processor (MLX4) can access 6kbyte 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.
