Smart sensors and actuators

The separation of logical and physical I/O functions affects the sensors and actuators. ICs targeted for conditioning sensor signals and driving actuators require enhancement with local intelligence and communication capabilities. Local intelligence maintains the state of the circuit and may run background diagnostics to detect sensor or actuator faults. The integrated communication interface includes at least a protocol handler such as a LIN responder implementation or even a simpler version of the CAN FD data link layer, such as CAN FD Light which was designed to remove the need for an MCU in edge nodes. Such integration would enable the smart IC to autonomously control a sensor or actuator and create a cost- and size-optimized solution that could be integrated into the sensor or actuator housing, as shown in Figure 6 (a).

For more complex sensors (such as a radar satellite) or composite actuators (such as a seat control unit with various motors), a classic approach based on a small ECU might remain the most efficient solution (see Figure 6 (b)). Additionally, dedicated signal lines from a zonal module (see Figure 6 (c)) can directly control very simple sensors or actuators.

Depending on aspects such as the number of control and sense signals, sensor and actuator complexity, and mounting constraints, designers may selectively choose any one of these solutions. Additionally, communication protocols such as CAN partial networking can function to reduce the power consumption of actuator modules by selectively waking the MCU only when a function is needed, allowing it to remain in low power mode for longer.