Proving the Business Case for the Internet of Things

AMS temperature sensor suits cold-chain monitoring

Steve Rogerson
June 30, 2016
Austria Microsystems has released a high accuracy temperature sensor with low power consumption for IoT markets such as cold-chain monitoring.
The 1.6 by 1mm AS6200’s typical current is 6µA at a measurement rate of four samples per second, and its digital measurement outputs are accurate to ±0.4ËšC. The factory calibrated device integrates in a single chip the functions required in a temperature sensing system, making it easy for users to design the sensor into their space-constrained or battery-powered products.
The device consists of a silicon bandgap sensor, analogue-to-digital converter, digital signal processor (DSP) and serial I2C interface. The on-chip DSP handles all linearisation and calibration, producing a 12bit (0.0625ËšC resolution) binary output.
Despite its high level of integration, it draws very little current. Operating from a supply range of 1.8 to 3.6V, it draws 1.5µA at a measurement rate of one sample per second. The conversion rate can be set in a range from 0.25 to 8Hz. At lower conversion frequencies, power consumption is lower. In standby mode, in which all the chip’s functions are turned off except the serial interface, it draws 0.1µA typical.
The device creates opportunities for manufacturers of battery powered, mobile and wearable devices to implement digital temperature sensing into new designs without paying a power or space penalty. Industrial process control systems and IoT applications such as cold-chain monitoring can be enhanced as space and power savings are realised.
“Backed by AMS’s proprietary low-power, high sensitivity analogue process, this results in the factory calibrated AS6200’s industry best combination of accuracy of ±0.4ËšC maximum between 0 and +65ËšC, low power consumption and small size of 1.6mm2,” said Christian Feierl, marketing manager at AMS.
The sensor’s I2C interface allows for two devices to be connected to one bus. The sensor also has a pin dedicated to an alert function, which triggers an interrupt at the host microcontroller when the measured temperature crosses a high or low temperature threshold set by the user.
The device is available immediately in production volumes. Unit pricing is €0.49 in order quantities of 1000. An evaluation board is also available.