How to design the motor driver for smart car seats

With the improvement of automobile intelligence, mid-to-high-end cars no longer have manual seat adjustment functions. Manufacturers have given seats more functions, such as heating and cooling.

The solution in this article is to accelerate the design of automotive heated/cooled seats through high-performance motor drivers and scalable, cost-optimized solutions.

This solution uses the DRV10983-Q1 motor driver and  the MSP430 G2553 microcontroller ( MCU ) for sensorless  BLDC  motor sinusoidal drive. The MCU is used only for speed control, while the DRV device is the main motor driver with integrated FETS to drive the motor. This design is specifically targeted at small motor modules, especially fans. This design enables proprietary sensorless control and allows tuning of motor parameters to optimize performance for the end application.

Its main features include:

12V driver capable of driving three-phase brushless DC (BLDC) motors with sinusoidal commutation

Single-layer design reduces manufacturing costs

使用专有的无传感器控制方案提供连续正弦波驱动，从而显著降低纯音

The MCU processes the speed input, controls the loop, and programs the motor parameters

The DRV10983-Q1 provides output slew rate and frequency configurations to increase   flexibility in tuning EMC performance

The DRV10983-Q1 device is a three-phase sensorless motor driver with integrated power MOSFETs that can provide up to 2 A of continuous drive current . The device is designed for cost-sensitive, low-noise, low external component count fan and pump applications. The DRV10983-Q1 device maintains register settings at 4.5 V and provides current to the motor when the supply voltage is as low as 6.2 V. If the supply voltage is above 28 V, the device stops driving the motor and protects the DRV10983-Q1 circuitry . This feature is capable of handling load dump conditions up to 45 V.

This device is available in two versions:

DRV10983Q：sleep version

DRV10983SQ：standby version

The DRV10983-Q1 device uses a proprietary sensorless control scheme to provide continuous sinusoidal drive, significantly reducing the pure-tone acoustics typically generated by commutation. The device's interface design is simple and flexible. The motor can be directly controlled through PWM, analog, or I2C inputs. Motor speed feedback is provided through the FG pin and the I2C interface.

The DRV10983-Q1 device has an integrated buck regulator that effectively steps down the supply voltage to 5 V to power internal and external circuits. A 3.3-V  LDO can also be used to power external circuits. The device can be used in sleep mode or standby mode to save power when the motor is not running. The standby mode (8.5 mA) version (DRV10983SQ) runs the regulator, and the sleep mode (48 μA) version (DRV10983Q) turns the regulator off. The standby mode version is used in applications where the regulator is used to power an external microcontroller. In this data sheet, the DRV10983-Q1 part number is used for both devices, DRV10983Q (sleep version) and DRV10983SQ (standby version), except for specific discussions of sleep versus standby functionality.

The I2C interface allows the user to reprogram specific motor parameters in registers and program the EEP ROM to help optimize the performance of a given application. Therefore, it is also very suitable for full-featured electronic seat products for mid- to high-end cars.