Choose a temperature sensor without worrying

As the "sense" of the Internet of Things to interpret the outside world, sensors are everywhere. Sensors can be used to detect events or changes in the environment and send messages to other electronic devices such as central processing units. It usually consists of a sensing device and a conversion device

digital temperature sensor

In the past, digital temperature sensors were widely used mainly in consumer electronics such as smartphones and smart speakers. With continuous technological innovation and the emergence of a large number of new use cases (such as predictive maintenance, autonomous machinery, process monitoring, equipment and robotics), while meeting the needs of accuracy, cost and industry standardization, digital temperature sensors have begun to be used in the industrial field and gradually Replace traditional analog sensors. This shift is largely attributable to the development of Industry 4.0 and the proliferation of digital devices and components in the market today. From the perspective of development trend, miniaturization, integration and low power consumption have become the core characteristics of digital temperature sensing devices.

• SGM457

As a digital output temperature sensor with low power consumption, low power supply, green SOT package, and serial control interface, SGM457 has an accuracy of ±0.5°C (TYP) in the temperature range of -40°C to +125°C, and is ideal for communication, computer Ideal for temperature measurement in , consumer, environmental, industrial, and instrumentation applications.

SGM457 supports I2C bus interface, since this serial bus uses multi-device access instruction, multiple SGM457 devices (up to four) can share one serial bus. In multiple hotspot monitoring applications such as computing platforms, this can be achieved by connecting a single serial bus to multiple temperature sensors. At the same time, to improve software efficiency, microcontrollers can communicate with these devices on the bus without sending separate instructions.

• SGM458

The SGM458 is a low power consumption, low power supply, green WLCSP package, digital output temperature sensor with serial control interface. The SGM458 is accurate to ±1°C (TYP) over the temperature range of -55°C to +125°C and has a supply voltage range of 1.6V to 5.5V.

Similar to SGM457, the serial two-wire interface supports traditional I2C bus or SMBus interface, and multiple SGM458 devices can share a serial bus. The microcontroller will communicate with these devices on the bus without sending separate instructions, which can be achieved by connecting a single serial bus to multiple temperature sensors in multiple hotspot monitoring applications such as computing platforms.

Analog temperature sensor

SGM446 and SGM447 are representative products of the analog temperature sensor series. Positive and negative temperature coefficients are optional, and the current output temperature sensor SGM446 can better support remote temperature measurement and temperature control.

• SGM446

The SGM446 is a two-terminal temperature sensor, the output current is proportional to the absolute temperature, and can be considered as a high-impedance regulator passing a constant current of 1μA/K within the supply voltage range of 4V to 35V, and the output current can be controlled at 298.2K ( +25°C) is calibrated to 298.2μA. Thanks to the high-impedance current output, the SGM446 is insensitive to voltage drops, especially on long lines, making it particularly suitable for remote sensing applications.

Compared with traditional temperature sensors, SGM446 not only does not require resistance measurement circuit, linearization circuit, precision voltage amplifier and cold junction compensation, but also integrates functions such as temperature compensation and bias proportional to absolute temperature. Additionally, the SGM446 enables multiplexing by switching current through CMOS multiplexers or switching supply voltages through logic gates.

• SGM447

The SGM447 is a high precision analog output CMOS integrated circuit temperature sensor in a green WLCSP package. It can operate from a supply voltage of 1.5V in the lowest gain configuration and simultaneously measure temperatures from -55°C to +150°C, and its low supply current makes it suitable for general temperature sensors and battery-powered systems.

With a Class AB output, the SGM447 is capable of driving heavy loads while providing strong source and sink current outputs, so it can be used to provide the input of sample-and-hold ADCs that require transient loads. Without using external components such as resistors and buffers at the output, the SGM447 can provide an output voltage that is inversely proportional to the measured temperature

epilogue

The latest research data shows that global sensor shipments will reach a record-breaking 30.8 billion in 2022, and the average selling price of total sensors will be 11% higher than that in 2021, which is the largest annual price increase in more than two decades.

It is particularly noteworthy that one-third of the sensors shipped in 2022 are IoT sensors represented by temperature, humidity, pressure, liquid level, and gas. According to the "2022-2027 Internet of Things Sensor Market Report" released by the research organization IoT Analytics, the market size of IoT sensors will reach 10.9 billion US dollars in 2022, and the compound annual growth rate is expected to reach 16% in the next five years. The connected sensor market is expected to reach $22.1 billion. Among them, the temperature sensor attracts the most attention. After all, the temperature sensor market is not only huge, but more and more smart products now have extremely high requirements for the monitoring and control of temperature parameters. It is no exaggeration to say that a slight change in temperature will have a huge impact on the environment, household products, industrial equipment, automobiles, servers, computers and many other industries.

Selecting a temperature sensor product may seem like a trivial task, but due to the wide variety of products available and multiple considerations such as sensor price, temperature range, accuracy, durability, sensor output, thermal stability, etc., the task can be overwhelming Quite daunting. However, with its core advantages such as high sensitivity, good linearity, fast response, low power consumption, long transmission distance, and small size, etc.