Kionix, a subsidiary of the ROHM Group, has developed a 32g accelerometer with the highest g value in consumer electronics.

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KIONix , a subsidiary of the ROHM Group, recently held a press conference in Beijing to announce the development of shock and acceleration detection applications that are particularly suitable for industrial and sports fitness equipment, and small acceleration sensors that support high g-value detection ranges. KX222/KX224”. The range is up to ±32g (Note: g is the standard gravity acceleration, equivalent to 9.8m / s2), respectively, using 2x2mm2, 3x3mm2 LGA package, to help the miniaturization of various high-performance applications.

Kionix's Shanghai representative office, Zhang Wei, introduced the background of the product launch.

Why do you first make high g values? Because of the current market, we can see acceleration sensors , especially for consumer electronics, with a range of up to 16g. Some new applications, such as motion trajectory and attitude detection, may encounter problems with insufficient range. For example, in a swing detector in a golf ball or a foot trajectory detection device on a soccer shoe, an instant Acceleration values ​​tend to exceed 16g, but due to human limitations, it will not exceed 32g. In addition, detection equipment such as motor vibrations of industrial equipment and consumer electronics often need to cope with instantaneous high g values.

What is the difficulty of doing 32g? The main difficulty in the actual situation is to realize the 32g motion detection range while ensuring that the system noise does not rise. Kionix found in the previous market research that some products have up to two hundred G However, the noise level also rises to the order of several G. Such a product will cause the user to detect the motion posture when doing some not particularly violent actions. However, the noise level of Kionix's KX222/KX224 products is maintained at the same level as the previous product, which is suitable for detection and identification of very slight motion.

Why is the mechanical vibration resonance frequency of the KX222/KX224 up to 6 kHz? Because the acceleration sensor is essentially a mechanical structure, any mechanical structure has its own resonant frequency, once the vibration frequency of the system or the detected object itself and the resonant frequency of the acceleration sensor When they are coincident, due to resonance, the mechanical structure in the acceleration sensor is destroyed, which may cause product failure. Therefore, the resonance frequency of the KX222/KX224 is made high, and it can be used to detect various motors in the industry, such as the drum of a washing machine or the click of a pulsator, and the vibration of the compressor of an air conditioner. The vibration frequency of these products is fixed during normal operation. Once the fault occurs, the vibration frequency will often change. The KX222/KX224 provides the corresponding algorithm to detect the vibration characteristics in real time to prevent the motor from causing problems due to its own problems. Serious problems, even in some special cases, can even determine the specific damage or abnormal parts, and the cause of the problem, such as the coil of a certain part of the rotor burned, or the power supply voltage is unstable. “Especially for some customers who make home appliances, this feature is very useful.” Zhang Wei pointed out, “We have some leading industry customers who are using this product to develop new products.”

Why does Kionix's KX222/KX224 support a very high data output rate of 25.6 kHz? Shannon's theorem tells us that if you want to effectively obtain data information, you must use at least 2 times the sampling rate, and the KX222/224 supports 25.6 kHz output. It detects about 4 times the maximum bandwidth, which is actually an oversampling that guarantees sampling accuracy without losing any valid information.

What are the features of the KX222/KX224? The digital interface can simultaneously support the more common I2C interface in consumer electronics [up to 3.4MHz] and the more common SPI interface in industrial applications [rate up to 10MHz]. Internally integrated 2Kbyte data buffer, can be configured as FIFO or FILO; with hardware wake-up, directional single/double-click tap detection and other hardware detection algorithm units.