Infineon launches new sensor for automotive TPMS applications

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Infineon launches new sensor for automotive TPMS applications [Copy link]

Infineon Technologies AG has launched the SP12 sensor for automotive tire pressure monitoring system (TPMS) applications. The device integrates silicon micromachined pressure and acceleration sensors, temperature sensors and a battery voltage monitor, providing four-in-one sensing functions and is equipped with a CMOS large-scale integrated circuit that can complete measurement, signal compensation and adjustment, and SPI serial communication interface. The pressure range
　　of the SP12 sensor is 100 to 450Kpa, and the pressure range of the SP12T sensor suitable for large vehicles is 50 to 1400Kpa. The acceleration of the SP12 sensor is between -12g and 115g, and the normal operating temperature range is -40 degrees to +125 degrees; the supply voltage is 1.8V to 3.6V.
In terms of detection accuracy, Infineon's SP12 is a silicon piezoresistive pressure sensor. It uses high-precision semiconductor resistance strain gauges to form a Wheatstone bridge as a force-to-electricity conversion measurement circuit, and its measurement accuracy can reach 0.01-0.03%FS. Since the working environment of the sensor is relatively harsh, drift will occur under different temperatures and different signal supply voltages, etc., and the SP12 has a compensation function that can detect and compensate for signals such as pressure, acceleration, temperature, and supply voltage, accurately providing the correct compensation values for different models of tires in different environments, effectively ensuring the measurement reliability. Since the battery of the sensor cannot be replaced, low power consumption and power saving of the system are very important. The SP12 sensor first adopts the wake-up transient working mode. When it works in the sleep working mode, its power consumption is only 0.6 microampere seconds. Secondly, Infineon has added an acceleration sensor to the sensor module. By using the sensitivity of its mass block to movement, the car can be automatically turned on before entering the system self-check. If the acceleration is detected to be very small (indicating that the car is not moving), the system is put into sleep mode, which can help reduce the system power consumption, thereby ensuring that the TPMS transmitter module can work for 10 years with a lithium battery. The working principle of the sensor is that it is connected to the transmitter module, fixed on the valve core, tire hub or placed in the tire tread, and the measured pressure and temperature signals are converted into electrical signals, and the signals are transmitted through a wireless transmitter. The air pressure information emitted by the sensor is received and processed by the receiver, and then displayed on the display installed on the driving platform for real-time monitoring during driving. Display methods such as LED, LCD or voice prompts can be designed according to customer requirements. Infineon's tire pressure monitoring system is mainly composed of sensors, transmitter modules and receiver modules. The sensor is used to detect tire pressure and temperature.