Automotive designers are constantly looking for devices that offer higher performance and flexibility than traditional position sensing technology. And these devices are also versatile and can be adapted to many applications. This need requires the integration of traditional contact sensor technology and non-contact sensor technology into the best design elements included in the device.

As today's cars utilize more and more electronics and control systems, engineers face the growing challenge of integrating these electronics into automobiles. This is especially true for sensors and other feedback (parameters) circuits that are used to ensure the safety of the car, reduce fuel consumption and reduce emissions.

In order to be consistent with processors that handle higher speeds and I/O functions, electronic system designers are always faced with various challenges in improving system resolution and signal quality. Mechanical flexibility, environmental stability, and signal integrity are key design features for any sensing technology used in today's automotive environments.

One of the requirements for electronic devices is the range of operating temperatures they can withstand. Temperatures range from -40 degrees Celsius to over +150 degrees Celsius in engine compartments, and sensors and related electronics face extreme temperatures that current materials can withstand. Further applications, such as variable turbochargers, continue to push this required extreme temperature up to +180 degrees. This requires sensor designers to develop materials and packages that meet these needs.

At the same time, the sensor must be able to accept a variety of mechanical configurations for the overall system requirements. Conventional inductive devices such as potentiometers and Hall effect devices (technical) can be used in either linear or ring packages. Both of the above technologies have their own advantages - potentiometers have lower cost, mature technology, and flexible mechanical structure, while Hall effect devices have low wear and good signal quality - which one to choose, depending on the application requirements of the system Come to fix. More advanced technologies like inductive sensors take advantage of both of these sensors to enable a more robust sensing system.

Potentiometer technology offers high design flexibility for line or ring applications. Depending on the design characteristics of the potentiometer, it provides an output signal that is proportional to the input voltage. However, this technique is somewhat limited by the characteristics of its analog output signal. Although this signal can be converted to a digital format, this conversion requires additional electronic components, increasing the cost of the sensor. Moreover, the converted signal is not yet a true high resolution digital format. As more and more high speed networks and communication buses are applied to automobiles, the need to arrange an AD converter for each potentiometer can be a disadvantage. Potentiometers are also a touch sensing technology that is prone to wear due to long-term work and vibration. When the wear of the potentiometer becomes very obvious, it will cause excessive noise in the signal. This can be a problem in the direct feedback control loop.

Figure 1: Traditional sensing techniques including potentiometers and Hall effect devices.

Hall effect sensors typically produce an analog signal. The device's communication with the automotive system is implemented by an ASIC that also converts the analog signal directly into a digital signal. Because Hall technology measures changes in Gaussian flux, a very sophisticated support system is needed to maintain its integrity. This limits the mechanical packaging flexibility of such devices to a certain extent. This type of carrying system also adds to the cost of the sensor to some extent. The advantage is that the Hall effect sensor is a non-contact technology and therefore does not degrade performance due to wear like a potentiometer. Typically, to control Gaussian magnetic fields that affect Hall effect sensors, such sensors have relatively short moving distances. Typically, Hall effect sensors are designed to have a rotation angle of less than 180 degrees or a linear motion distance of less than 25 millimeters.