Temperature sensors are an electronic device for measuring temperature, whose main function is to convert temperature signals to telecommunications output. Different types of temperature sensors apply to different applications and are now widely used in areas such as industrial automation, medical care, environmental monitoring and consumer electronics. With the rise of emerging industries such as auto-driving and the networking of goods, the market for temperature sensors is expanding. At the same time, market requirements for temperature sensors are becoming more stringent with regard to such criteria as sensitivity, size and utility。
On 30 august, at 15:00, the sixty-eighth issue of the micro-public course was broadcast live, and march hu, director general of the temperature sensor lines, shinsing synthetic electronics co. Ltd., shanghai, delivered a keynote address on “a world with a core”. At the centre of the temperature sensor, the thermometers and their principles, the temperature sensor ic workings, the chip parameters and the product advantages and characteristics of the similiac are explained in depth and shallow。
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Market-driven sensor ic replacement
March hu introduced four contact sensors. The first, also most common, is thermistor, also known as heat-sensitive electrical resistance; the second, called sensor ic, is also more complete in similiac; the third, is the thermocouple thermal voltage, which is much wider in temperature detection than that of thurmister and sensor ic; and the fourth, the electrical resistance temperature detector rtd, a common platinum resistance, is a precious metal that changes in linearity with temperature。
March hu indicates that each of the four sensors has advantages and disadvantages, of which the heat-sensitive electrical resistance is low in price, but with a large margin of error, thermal-sensitive electrical resistance system aggregates and detects temperature errors of approximately ±3 ±5 °c; the sensor's ic accuracy, which does not require secondary calibration, achieves absolute accuracy of ±0. 1 °c, but with a relatively limited temperature range; the thermoelectric doll is suitable for use in a high-temperature environment, with a working temperature range ranging from -260 °c to +2700 c; and the rtd sensor is a non-sourced device, which requires incentives for electrical currents in conjunction with metrological measurements of resistance and relative complexity of peripheral circuits。
From march hu's summary of the four sensors, the temperature sensor ic does not dominate the temperature range, usually -55°c ~200°c, due to ccos circuit condensation and containment material restrictions. It can be seen that heat-sensitive electrical resistance, thermoelectric dolls and rtds are much wider in the temperature range than ic. However, in the latter parameters, the advantages of the temperature sensor ic are clear。
March hu states: “firstly, ntc is less precise and the sensor ic can calibrate to the absolute accuracy of ± 0. 1°c; secondly, in terms of onlineity, ntc temperature and resistance curves are naturally non-linear, requiring secondary data processing, which may lead to higher production costs, but the sensor ic does not have a problem with secondary accuracy calibration; thirdly, in terms of interfaces, the sensor i2c/smbus, i3c, spi, uart etc. Can support generic interfaces to achieve multi-drop structures. However, ntc only supports point to point, and each ntc temperature measurement requires the occupancy of the adc channel along the way, or the use of analogue switches for route switching.”
The ct1721 product, a 2-end temperature sensor ic, only dio (data tabulation) and gnd, draws electricity from dio. The product size can be 0. 6 mm x 0. 6 mm, with a maximum of 9 ct1721 on a single bus. This leaves no additional hardware cost for the temperature sensor ic to replace ntc resistance. Thanks to this, many customers are also gradually replacing heat-sensitive electrical resistance with temperature sensor ic。
How does the temperature sensor ic choose
With regard to the temperature sensor ic, march hu provides detailed information on working principles, circuit composition, categories, key parameters, etc。
According to march hu, “many customers are interested in the measurement principles and internal composition of ic when they communicate technology, using p-n knots essentially as a temperature sensor unit, using the temperature of their volt curves to know the increase and decrease of external temperature. It's based on the vulcan curve. The currents range from the positive to negative poles of the power, and the volam curve is the top right figure. Following the transfer, the current will rise rapidly with the voltage, in addition to a reverse saturated current, which will be smaller in the long term, and will be punctured when it reaches the piercing pressure.”
“it is clear from the figure that when the temperature rises, the pn knot produces the same positive current, and the voltage required is reduced. We are using the correlation between pn voltage and temperature as the basis for temperature sensors. Of course, it needs to be made into a very accurate temperature sensor, not just a principle, but more detailed consideration. "march hu adds。
Thermal sensors known to ic include local only, local + remote, temperature switch and signal coNditing four types of ic. March hu explained that “local is attached to the chip by p-n, which measures its own ambient temperature; local + remote is characterised by measuring the temperature of multiple physical positions, first by measuring the ambient temperature of the chip itself through internal pn knots and also by measuring the temperature of other physical positions by means of an external tripolar tube; temperature switch is primarily conducting temperature threshold alerts that can be used as power protection; signal coNditing ic, a thermoelectric chip, has mature products of this type.”
The temperature sensor ic has many important parameters, and what should be the focus of the buyer? In the view of march hu, including measurements of temperature ranges, measurements of accuracy, vcc domain associated with mmu and interfaces are parameters to be considered。
March hu emphasizes heat response time (respo)Nse time) is also the focus of increasing client attention. Since measured temperatures are often not closely connected to the chips, and there may be parts of the medium in the middle, increasing numbers of clients are concerned about thermal conductivity of the chips。
But the real response time is not measuring the whole process, and we'll use 63 percent of the amount as a reference. March hu gives an example, for example, from 0 to 100°c, and we just have to see how long it takes to change to 63°c. This time unit is seconds, reflecting the ability of the chip to heat。
A number of high-quality products have also been introduced in the field of shin plume temperature sensors。
The product varies
For 30 or 40 years, foreign manufacturers have made a series of temperature sensors and occupied most markets, and why did shin xin ling enter the industry in 2012
March hu states that better performance can be achieved because the sensin lactation temperature sensor ic is fully compatible with the foreign manufacturer's tripod sealing and solidware drive for its products. In comparison to foreign manufacturers' equipment, thing can be better done on the core “precision” indicator. In addition to this, the resolution of the shinsimite product will be lower, the power will be lower, the vcc support will be wider and the interface will be faster..
March hu further states that shinsing has focused on high performance reliable temperature measuring chips, combined with higher value for money and customer service capabilities, accompanied by an alternative wave of national production, and that shinsing's temperature sensor class is widely accepted domestically。
March hu also listed a number of special features, including ct1721r, ct1721r, ct7117 and cht8555 for smart wear, cts7510, ct7428, specialty ct7035l, etc。
March hu also presented the future layout of the chip in the car field. He indicated that cars were a more popular track, that shin would certify products of better working quality and mass use, and that customers were already purchasing and using shenzhen class temperature sensors. But we have not done any more to publicize it, because what we need to do first is to be of good quality。
Finally, the presentation was summarized by march hu, who said, “when making a thermosensor product line, shinsim puts quality, stability, high performance first and is reflected in the chip. In addition to the temperature sensors, shin lactation includes more subdivided categories such as products with higher performance requirements. The products of these products will reflect a stronger design advantage. It is to be hoped that when you use the temperature sensors, or when you want to know the temperature sensors, you will first think of the national manufacturer, shin yi ling, and you will know that we are trying to make the temperature sensors very sound and powerful, which we want to convey to you.”
(reading/sun lok)
