A vehicle-mounted power tailgate (PLG) is an electronic vehicle system that uses an electric motor to automatically open and close the tailgate (back door) at the rear of the vehicle.
Replacing the conventional manual opening and closing mechanism, this system is being adopted in many vehicles, primarily SUVs and minivans.
PLGs can be opened and closed using SWITCHES, smart keys, or foot movements (kick sensors). In recent years, they have evolved into important systems with more advanced features, such as a memory function that stops the tailgate at a desired opening angle and anti-pinch protection through obstacle detection. In addition to improving convenience and comfort, they have become indispensable from a safety perspective.

The PLG (Plant Lock Generator) is a control system that detects user opening and closing commands and appropriately drives the tailgate. It mainly consists of an opening/closing SWITCHES /sensor, an ECU (Electronic Control Unit), a motor driver, an electric motor (spindle drive), and position and ELECTRIC CURRENT SENSORS.

The operation of the power tailgate begins when the user operates SWITCHES, smart key, or kick sensor. The ECU, upon receiving the operation signal, determines whether to open or close the tailgate and sends a control signal to the motor driver. The motor driver uses an H-bridge circuit or similar to drive a DC motor (spindle drive) and moves the tailgate in the desired direction.
What's important here is that it's not just about running the motor, but also constantly monitoring its operating state. For example, if it comes into contact with an obstacle such as a person or luggage during opening or closing, the motor current and rotation speed will change. By sensing these changes, the ECU ensures safety by stopping or reversing the operation if it determines that there is an abnormality.

Designing a power tailgate requires simultaneously addressing multiple technical challenges. A prime example is the anti-pinch function. When the tailgate operates and traps a person or obstacle, the resulting load change must be detected as quickly and accurately as possible. A delayed response compromises safety, while excessive sensitivity leads to false detections and impairs usability, making it a very difficult design to balance.
Furthermore, the tailgate requires significant torque and power consumption to drive large and heavy components. As vehicles become more electrified, the importance of power efficiency and heat dissipation measures is also increasing. Standby power and the efficiency of control circuits have a considerable impact on the overall power consumption of the vehicle. In EVs in particular, optimizing the power consumption of these auxiliary systems is more important than ever before.
Furthermore, miniaturization of circuits and components is crucial because mounting space and wiring are limited around the tailgate. In addition, it is necessary to address automotive-specific requirements such as noise and EMI countermeasures associated with motor drive, resistance to temperature and humidity fluctuations in outdoor environments, and long-term reliability.

Recent power tailgates have evolved from simple motor-driven systems to more sophisticated electronic control systems. While many older systems used manual opening and closing or relatively simple relay-based methods, semiconductor-based H-bridge control has become commonplace, enabling more flexible and precise control.
Furthermore, the shift in control from analog circuits to an MCU makes it easier to add functions and tune the system via software. This facilitates more advanced control, such as optimized pinch detection, memory stop at arbitrary opening angles, hands-free (kick sensor) opening and closing, and learning functions. In addition, integration with peripheral functions such as smart keys and body control is progressing, and it is expected that system optimization at the vehicle level will accelerate even further in the future.

In actual designs, a common configuration involves motor drive using an H-bridge as the base, combined with feedback control that incorporates current detection and position detection. Here, factors such as the required detection accuracy, the timing of anomaly detection, and how to handle temperature and component variations greatly influence system quality.
Furthermore, many challenges in the design field are difficult to solve through theory alone. Typical examples include deviations in current detection values due to temperature changes, inrush current during motor startup, the effects of noise due to wiring length, and the trade-off between false detection and response speed. To address these practical challenges, a comprehensive approach is essential, including not only device selection but also circuit design, control algorithms, and layout design.

Automotive applications such as power tailgates require not only functionality but also a high level of safety, reliability, and efficiency. This necessitates semiconductor devices suitable for motor control, highly accurate sensing capabilities, and control solutions that meet automotive quality standards.
Infineon offers a wide range of solutions to meet these requirements, including motor control, POWER SUPPLIES control, and MCU control. This makes it easier to achieve values such as improved pinch detection accuracy, lower power consumption, smaller ECUs, and higher system reliability.