How to Drive Electric Motors in Modern Cars?


If you are curious to know how your car’s air-conditioning system motors or seat motors work, walk-through these reference designs.

Today’s new cars can include more than 30 body motors used in applications ranging from window regulators, mirrors and adjustable car seats to sunroofs, lights and air-conditioning systems. These systems of comfort and necessity will become increasingly automated and programmed according to the passenger’s preferences.

Brushed DC motors are the traditional solution for driving most electric convenience features in an automotive body. Since the brushes provide the commutation, these motors are simple to drive and are relatively inexpensive. In some applications, brushless DC (BLDC) motors can provide significant benefits in terms of power density, thus reducing weight and providing better fuel economy and lower emissions. Manufacturers are using BLDC motors in windshield wipers, cabin heating, ventilation and air conditioning (HVAC) blowers and pumps. In these applications, the motor tends to run for long periods, as opposed to momentary operation such as in power windows or power seats, where the simplicity and cost-effectiveness of brushed motors still hold an advantage.


Mentioned below are some motor control reference designs well-suited for today’s automotive environments:

Compact Automotive HVAC Control Module For HEV/EV

TI offers a small and compact reference design for an automotive high voltage, high power motor driver for HVAC compressor. This brushless DC (BLDC) motor reference design controls an automotive HVAC (heating, ventilation, and air conditioning) compressor by using the UCC27712-Q1 high-side and low-side gate driver followed by discrete insulated-gate bipolar transistor (IGBT) half bridges. This reference design uses TI’s InstaSPIN software with a three-phase motor control algorithm, which the designer can enable using special libraries in the read-only memory (ROM) of Piccolo microcontrollers (MCUs) and provides expert tools to designers of sensorless (velocity and torque) motor control applications.

BLDC Motor Driver Boosts Battery Runtime In IoT/Portables

Click here for the reference design.

Seat Fan Motor Driver

The seat ventilation fan can be either a Brushed DC (BDC) motor or Brushless DC (BLDC) motor. The motor driver will correspond to the motor type, and may include rate control, current sense, diagnostics and sensorless commutation circuitry.

TI offers a design for a sensorless BLDC motor sinusoidal drive using the DRV10983-Q1 motor driver and MSP430G2553 microcontroller (MCU). The MCU is only used for speed control while the DRV device is the main motor driver with integrated FETS which drives the motor. This design specifically targets small motor modules, particularly fans. This design allows access to proprietary sensorless control and the ability to tune motor parameters to optimize performance for the end application.


• Full Featured Seats
• Heated / Cooled Seats

Click here for the reference design.

Automotive Power Trunk Lift Motor Drive

The use of electrically-powered drivers to raise and lower automotive trunk lids, liftgates, and engine hoods is becoming more common. The most common types of trunk liftgates use a brushed DC motor that responds to commands from control switches in the cabin or switches on a key fob.
This reference design describes how to drive an automotive trunk lift or rear gate lift. In this design, a brushed BD lift motor and electromagnetic clutch drive mechanisms for a typical gear driven lift. This design includes a warning beeper, LED indicator, and directional control that uses an automotive motor driver and high side switch. A current-controlled gate driver with slew rate control helps improve MOSFET efficiency and decrease switching spikes. This design offers a simple, robust implementation with a low component count and small board space compared to relay solutions.

FPGA Reference Design For Machine Learning


• Power Trunk Lifts
• Power Liftgate
• Power Hood Lift

Click here for the reference design




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