All-in-one LIN motor drivers reduce BOM and PCB

Melexis has introduced the third generation of its integrated single-chip LIN drivers for small motors targeting automotive mechatronic applications at up to 10 W. Applications include motor-controlled flaps and valves, and small fans and pumps.

The Gen 3 MLX81330 (0.5 A motor drive) and MLX81332 (1.0 A motor drive) smart LIN drivers are based on high-voltage silicon-on-insulator (SOI) technology for robustness and function density. The LIN drivers combine analog and digital circuitry in single-chip solutions that are compliant with the industry-standard LIN 2.x/SAE J2602 and ISO 17987-4 specifications for LIN slave nodes.

In addition to the integrated motor driver, the LIN drivers feature extensive I/O capability and a dual-microcontroller architecture where one core is dedicated to communications while the second microcontroller runs the application software. Along with the analog-ready I/O, they can 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 32 KB Flash memory with ECC, 10 KB of ROM, 2 KB of RAM and 512 bytes of EEPROM with ECC. The communications processor (MLX4) can access 6 KB of ROM and 512 bytes of RAM. The embedded motor controller ICs are designed for safety applications according to ASIL-B (ISO 26262).

The LIN drivers also include 5 x 16-bit PWM timers, 2 x 16-bit timers, and a 10-bit ADC, along with a differential current sense amplifier and temperature sensors. Overcurrent, overvoltage and over-temperature detection/protection is also integrated.

Melexis said the all-in-one approach enables a reduced bill of materials (BOM), smaller printed circuit board, simpler product design, and faster assembly. One example cited is an application where the MLX81332 interfaces directly with an electronic control unit and can drive up to four phases of a motor, with a maximum current of 1 A per phase, or two phases with a maximum current of 1.4 A.

“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,” said the company.

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