Application and solutions of automotive MEMS sensors and passive components in the automotive industry

Key fundamental components in modern Automotive

Automotive MEMS sensors and passive components are key fundamental elements in modern automotive electronic systems, supporting diverse vehicle functions in safety, powertrain, body control, and intelligence. MEMS sensors utilize microstructures to achieve high-precision measurements and are widely used in automotive systems such as accelerometers, pressure sensors, gyroscopes, flow meters, and microphones. They support core functions including airbag deployment, Tire Pressure Monitoring Systems (TPMS), Electronic Stability Control (ESC), Electric Vehicle Battery Management Systems (BMS), navigation, and positioning. In the era of autonomous driving, they are also used for data fusion in various perception systems, enhancing the vehicle's ability to assess environmental and dynamic changes.

Passive components (such as resistors, capacitors, inductors, crystal units, etc.) undertake critical tasks including power management, signal conditioning, noise suppression, Electromagnetic Compatibility (EMC), and high-temperature endurance, ensuring stable vehicle operation even in complex environments. As automotive electronic architectures evolve towards zonal/domain control, and with the increasing demands for high-voltage systems and high-speed communication in new energy vehicles, passive components characterized by high reliability, high voltage resistance, high frequency, and low losses have become even more indispensable.

In summary, automotive MEMS sensors provide "accurate perception," while passive components offer "stable support." Together, they form the electronic foundation of intelligent vehicles, making them safer, more energy-efficient, and smarter, thereby driving the continuous development of future autonomous driving and electrification technologies.

For automotive applications, Murata offers a series of related solutions covering MEMS sensors, thermistors, capacitors, inductors, crystal units, and more. The following sections will introduce these product series.

Automotive 6DoF gyroscope and accelerometer sensor

Murata's SCH1600 is an automotive-grade, single-package 6DoF gyroscope and accelerometer sensor. The SCH1600 sensor family offers greater design flexibility through redundancy design options and built-in configurable dual output channels. The SCH1600 supports an angular rate measurement range of ±300°/s and an acceleration measurement range of ±8g. It features an auxiliary digital accelerometer channel with a dynamic range up to ±26g. Gyroscope bias instability is as low as 0.5°/h, and angle random walk can be as low as 0.03 °/√Hz. It provides options for output interpolation and decimation, and features Data Ready output, Timestamp index, and SYNC input functions for clock domain synchronization. It operates over a temperature range of -40 to 110°C, with a supply voltage of 3.0 to 3.6V and an I/O supply voltage of 1.7 to 3.6V. It supports the SafeSPI v2.0 interface, allows selection of 20-bit and 16-bit output data via the SPI frame, and incorporates extensive self-diagnostic features utilizing over 200 monitoring signals. Its dimensions are 11.8mm x 13.4mm x 2.9mm (L x W x H), utilizing an inverted SOIC-24 housing. It is qualified according to AEC-Q100 Grade 1, comes in a robust, RoHS-compliant SOIC plastic package suitable for lead-free soldering processes and SMD mounting, and is based on proven capacitive 3D-MEMS technology.

The SCH1600 sensor delivers leading-angle random walk and bias stability in the market, ensuring high-quality gyroscope signals even within integration times of just a few seconds. Its fast data rates, time synchronization capabilities, and high performance enable efficient IMU signal sharing across all vehicle subsystems, from HUD control to camera and headlight leveling.

This product is equipped with over 200 internal monitoring signals, achieving a high level of functional safety performance in the market. The orthogonality of the measurement axes is calibrated at Murata, allowing system integrators to bypass this costly and performance-critical process step.

The SCH1600 series is an ideal single-package 6DoF device intended to serve as the central vehicle IMU, providing high-quality signals to all vehicle subsystems even in extremely harsh environments. It achieves this through data fusion with GNSS and various perception sensors like cameras, radar, and Lidar. Representative application areas include Advanced Driver Assistance Systems (ADAS), Automated Driving (AD), Inertial Navigation, Advanced Vehicle Stability Control, Dynamic Leveling and Headlight Leveling.

Thermistors and ceramic capacitors for automotive powertrain/safety equipment

Murata also offers the NCU03WF104F6SRL thermistor, suitable for automotive powertrain and safety equipment. Its length and width dimensions are 0.2 x 0.1 inches. It has a resistance value (at 25°C) of 100kΩ with a tolerance of ±1%. Its B-Constant (25/50°C) is 4,250K with a tolerance of ±1%. The B-Constant reference values are 4,303K at 25/80°C, 4,311K at 25/85°C, and 4,334K at 25/100°C. It supports a maximum voltage of 5V, with a maximum operating current (at 25°C) of 0.031mA and a typical dissipation constant (at 25°C) of 1.5mW/°C. It operates over a temperature range of -55 to 125°C, features an SMD package, and has a Moisture Sensitivity Level (MSL) of 1.

The NCU03WF104F6SRL thermistor offers excellent solderability and environmental stability, as well as excellent long-term aging stability. It features high accuracy in resistance and B-Constant, supports reflow soldering, maintains the same B-constant for the same resistance value across three sizes (0603/0402), has a smaller size for easier use in circuits, and is lead-free.

Murata's GCM series are chip multilayer ceramic capacitors designed for automotive powertrain and safety equipment. They are AEC-Q200 compliant capacitors for automotive applications such as powertrain systems and safety control equipment. They can be used in safety equipment like drive system control for engine ECUs, airbags, and ABS. They pass more stringent test conditions compared to general-purpose products (GRM series), even in temperature cycle and humidity load tests.

Compared to the general-purpose GRM series' maximum operating temperature of 125°C, the automotive GCM series raises the maximum operating temperature to 150°C. The GRM series undergoes a temperature cycle test of 5 cycles, while the GCM series undergoes 100 cycles (1000 cycles for AEC-Q200 compliant products). The GRM series humidity load test conditions are Temperature: 40±2°C, Humidity: 90-95%RH, Duration: 500 hours. The GCM series test conditions are Temperature: 85±2°C, Humidity: 80-85%RH, Duration: 500 hours (1000 hours for AEC-Q200 compliant products). They are suitable for application temperatures of 125°C and 150°C, with product lineups available for 150°C use in engine compartments. The external electrodes are tin-plated, offering excellent solderability. The GCM series has a wide range of specifications, with product sizes from 0.4 x 0.2mm to 5.7 x 5mm, rated voltages from 2.5Vdc to 1,250Vdc, and capacitance values from 0.1pF to 220µF. Primary applications include drive system control for engine ECUs, airbags, ABS, and other safety control equipment.

Murata also offers a series of safety standard certified metal terminal type multilayer ceramic capacitors suitable for automotive (powertrain/safety) systems. The model is KCA55HR7MF152KU01# (the "#" at the end indicates the package specification code), with variants like KCA55HR7MF152KU01L, KCA55HR7MF152KU01K. They can be used in consumer equipment, industrial equipment, automotive infotainment/comfort equipment, automotive powertrain/safety equipment, medical equipment [GHTF A/B/C] except for implantable devices, and mobile electronics.

The KCA55HR7MF152KU01# multilayer ceramic capacitor has a chip size code (mm/inch) of 5750M/2220. Its length is 6.1mm ±0.4mm, width is 5.1mm ±0.3mm, thickness is 2.4mm ±0.2mm, the 'd' dimension is Min. 4mm, and the metal terminal width 'e' is 0.9mm ±0.2mm. It conforms to EIA temperature characteristics (standard specification) with X7R characteristic. The temperature range for the characteristic and operating temperature is -55 to 125°C. The KCA55HR7MF152KU01# capacitor has a capacitance of 1,500pF with a tolerance of ±10%. Its X1 rated voltage (DC) and Y2 rated voltage (DC) are both 1,000Vdc. Its X1 rated voltage (AC) and Y2 rated voltage (AC) are both 500Vac (r.m.s.).

Comprehensive automotive multilayer inductors and crystal units

Murata also offers the automotive multilayer inductor LQG15HH10NG02# (the "#" at the end indicates the package specification code), with variants like LQG15HH10NG02D, LQG15HH10NG02J, LQG15HH10NG02B. It can be used in automotive infotainment/comfort equipment, automotive powertrain/safety equipment, and medical equipment [GHTF A/B/C] except for implant, surgery, and auto-injector applications. The LQG15HH10NG02# multilayer inductor has a length of 1mm ±0.05mm, width of 0.5mm ±0.05mm, and thickness of 0.5mm ±0.05mm. Its size code is 1005/0402 mm(inch).

The LQG15HH10NG02# multilayer inductor has an inductance of 10nH ±2%, measured at a test frequency of 100MHz. Its rated current (based on temperature rise) is up to 500mA, with a maximum DC resistance of 0.26Ω. Its self-resonant frequency is 3,400MHz, and its Q factor (minimum) is 8, measured at a test frequency of 100MHz. It operates over a temperature range of -55 to 125°C, is non-shielded, and supports reflow soldering.

Furthermore, Murata offers inductors for power lines for automotive use. It provides a wide range of inductor product families manufactured using multiple techniques such as wound metal alloy, multilayer type, and wound ferrite core, covering sizes from 1.6mm x 0.8mm to 12mm square. Metal alloy inductors, also known as metal composite inductors, support high currents by using metal materials that are less prone to magnetic saturation. They can be used in a wide range of high-current power circuits from smartphones to home appliances and automotive devices, including the DFEC/DFES series. The multilayer type features small size and low profile, such as sizes smaller than 0805 (2012) and heights of 0.6mm, making them suitable for low-power circuits like wearable devices and smartphones, such as the LQM series. The wound type uses a ferrite core, and a key advantage is its extensive lineup supporting inductance values above 100µH. They are suitable for step-up power supply circuits like backlights and choke applications, including the LQH series and DEM series.

Murata's automotive power line inductors cover a very wide range of inductance values, from as low as 0.15µH (e.g., DEF201612PD) to as high as 1mH (e.g., MDH10060C). The supported rated currents range from 160mA (e.g., LQM21DH_70) to 13A (e.g., MDH10060C), meeting diverse automotive application requirements.

In communication functions like BLE and Zigbee, the typically required frequency accuracy for crystal units is ±40ppm. In recent years, communication functions requiring such high accuracy have been widely equipped in automobiles. Previously, if crystal units were used in applications requiring high-temperature operation and long-term reliability like automotive, they could not meet the accuracy requirements, necessitating tuning processing with ICs, which led to higher design and manufacturing costs.

Murata offers the XRCGE_M_F series crystal unit for automotive applications. This is a surface mount type crystal unit supporting frequencies from 32 to 50 MHz, with dimensions of 2.0 x 1.6 x 0.7mm. It uses a resin-sealed package and complies with AEC-Q200. Murata achieves downsizing through its original packaging technology and eliminates defect risks through inorganic particle screening. Murata also achieves an overall accuracy of ±40ppm (including temperature characteristics and aging) for the first time through high-temperature, high-precision design. Customers do not need IC correction (no tuning required), thus significantly reducing design man-hours and manufacturing costs. It can be used for wireless communication functions (BLE/Zigbee, etc.) in automotive applications like TPMS, RKE, and BMS.

Conclusion

As the automotive industry advances towards higher levels of intelligence, electrification, and connectivity, the importance of automotive MEMS sensors and passive components continues to rise. Whether it is precise sensing data, a stable power environment, or the long service life brought by automotive-grade reliability, these key components collectively form the foundation of vehicle electronic systems, enabling the stable operation of advanced driver assistance, automated driving, powertrain control, and vehicle stability systems. The MEMS sensors and passive components launched by Murata will be key to enhancing the competitiveness of your automotive electronic designs and will also become a core force driving the continuous breakthroughs of next-generation intelligent vehicles.