TPMS is the English abbreviation of "TIrePressureMonitoringSystem", which is mainly used for real-time automatic monitoring of tire pressure when the car is running, and alarm for tire leakage and low air pressure to ensure driving safety. Early warning system for the life safety of the driver. TPMS tire pressure monitoring module consists of five parts: (1) Smart sensor SoC with combination of pressure, temperature, acceleration, voltage detection and post-signal processing ASIC chip; (2) 4-8 bit single chip microcomputer (MCU); (3) RF radio frequency transmitting chip; (4) Lithium sub-battery; (5) Antenna. See Figure 1, Figure 2 is a physical picture of the finished product. The shell is made of high-strength ABS plastic. All devices and materials must meet the automotive temperature range of -40 ° C to + 125 ° C. Figure 2 The physical picture of the finished product of the TPMS tire pressure monitoring module The smart sensor is a pressure sensor, acceleration sensor chip integrated with silicon micromachining (MEMS) technology, and a temperature sensor, battery voltage detection, internal clock and analog-to-digital converter (ADC), and sample / hold (S / H) ), SPI port, sensor data calibration, data management, ID code and other functions of the digital signal processing ASIC chip. With mask programmability, it can be configured using customer-specific software. It is made up of several chips of MEMS sensor and ASIC circuit, which are made in a package with integrated circuit technology (Figure 3). A pressure / temperature introduction hole is left above the package (Figure 4), and the pressure is directly introduced on the stress film of the pressure sensor (Figure 5), and this hole also directly introduces the ambient temperature into the semiconductor temperature sensor. The MEMS silicon piezoresistive pressure sensor adopts the inner wall of a circular stress silicon film fixed on the periphery, and uses MEMS technology to directly engrave four high-precision semiconductor strain gauges on the surface of the maximum stress, forming a Wheatstone measuring bridge as a power electricity When the measurement circuit is changed, the physical quantity of pressure is directly converted into electric quantity, and its measurement accuracy can reach 0.01-0.03% FS. The structure of the silicon piezoresistive pressure sensor is shown in Figure 5. The upper and lower layers are made of glass, and the middle is a silicon chip. There is a vacuum cavity on the top of the stress silicon film, making it a typical absolute pressure sensor. In order to facilitate the identification of the TPMS receiver, each pressure sensor has a unique 32-bit ID code, which can generate 400 million unique numbers. Figure 3 Pressure, acceleration and ASIC / MCU combination package in one package Figure 4 Pressure / temperature inlet Figure 5 Silicon piezoresistive pressure sensor structure Hp Pavilion 15-Cs 15-Cw,Hp 15-Cw Top Cover,Hp 15-Cs Palmrest,Hp Replacement Parts S-yuan Electronic Technology Limited , https://www.laptoppalmrest.com
