TPMS pressure sensor introduction: NPP301 and SM5420

Today, we are going to talk something about the TPMS.

The automobile tire pressure monitoring system (TPMS) is mainly used for automatic monitoring of tire air pressure in real time when the vehicle is running, and alarming for tire leakage and low air pressure. At present, the TPMS system has quickly become the basic equipment to avoid accidents, and more and more vehicles have installed this system.

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There are two main types of TPMS, one is Indirect TPMS (Wheel-Speed Based TPMS). The other is Direct-Sensor Based TPMS. In July 2001, the US Department of Transportation and the National Highway Safety Administration jointly evaluated the two existing TPMS systems. The evaluation report concluded that the direct TPMS is superior to the indirect TPMS in terms of function and performance, thus enabling direct development. TPMS has become a popular trend.

TPMS pressure sensors are based on MEMS technology, mainly including integrated capacitive pressure sensors (such as Freescale's MPXY8020, MPXY8040) and tantalum piezoresistive pressure sensors (such as the universal NovaSensor's NPX1, NPX2, SMI's SM5420). The piezoresistive pressure sensor uses a high-precision semiconductor resistance strain gauge to form a Wheatstone bridge as a force-electric conversion measurement circuit, and its measurement accuracy can reach 0.01-0.03% FS.

Pressure-resistive pressure sensors (NPP301 and SM5420) are suitable for most non-corrosive gases and dry air measurements. Features Ultra-small, ultra-low cost surface mount (SO-8) structure for automated component placement Operating temperature: -40°C to 125°C Static accuracy <±0.2% FSO provides absolute pressure ranges of 100, 200 and 700Kpa , application of automotive tire pressure testing, medical equipment, air conditioning equipment, cable leakage detection, pressure switches and controllers portable barometers, altimeter consumer instruments. NPP301 and SM5420 are surface mounted silicon pressure sensors, which use silicon-silicon fusion technology The ultra-small piezoresistive chip with high stability is sealed in a plastic case. The pin structure of the integrated circuit can be installed in a small space, thus providing a low-cost product to a large number of OEM users. Under constant voltage supply, a voltage signal proportional to the input pressure is generated, which can be amplified or added by the user through a signal conditioning circuit to meet the requirements of its own product.

NPP301 and SM5420 characteristic parameters:

Pressure range 0 ~ 100kPa ≈ 15, Psi0 ~ 200kPa ≈ 30, Psi0 ~ 700kPa ≈ 100Psi overload 3X. Rated pressure electrical performance (25 ° C) power supply 3.0V maximum 10V. DC input impedance 5000±20%Ω Output impedance 5000±20%Ω Environmental conditions Electrostatic damage (ESD)>10kv Operating temperature-40～125°C Physical property Weight≈0.10g Compatible medium Clean, dry, non-corrosive gas technical index ( All test values are relative to 22 ° C, 3 V constant voltage supply) Zero output ± 10 mV full output 60 ± 20 mV linearity ± 0.20% FSO hysteresis and repeatability ± 0.10% FSO zero temperature coefficient ± 0.04% FSO / ° C resistance temperature coefficient 0.30 %/°C Sensitivity Temperature Coefficient -0.20VV%FSO/°C Zero Thermal Hysteresis ±0.10% FSO Long-Term Stability ±0.20% FSO Dimensions Unit: mm (in) Selection Series Range Package Type NPP-301-100A100kPa (15Psi) SO-8NPP-301-200A200kPa (30Psi) SO-8NPP- 301-700A700kPa (100Psi) SO-8

Hope you all have learned from this article.