On Monday, December 18, 2017, ams announced the launch of their newest data-logging NFC sensor tag, the AS39513. When incorporated into smart labels, this sensor can track the state of temperature-sensitive materials, including food, pharmaceutical, and health care products. In their press release, ams said this new sensor could help “pav[e] the way to farm-to-fork item-level tagging” because of its yearlong battery life.
What Can the AS39513 Do?
The AS39513 can log up to 1,020 sensor readings with time stamps. Using an NFC-enabled smartphone, users can download a list of these readings by scanning the smart tag within a few centimeters away. The sensor also complies with ISO15693 and NFC-V (T5T) standards, so users can read multiple AS39513 smart tags at once by using an ISO15693-enabled device within 1–2 meters.
Figure 1. Product specs for the AS39513. Image courtesy of ams.
Giancarlo Cutrignelli, head of marketing for wireless sensor nodes at ams, said the sensor requires no complex software or firmware. In addition, the AS39513 comes with the following features:
- Real-time clock
- 10-bit ADC
- Configurable data-logging engine
- 9kbit password-protected EEPROM
- Serial peripheral interface (SPI)
The sensor is currently available in a 0.33-mm chipscale package or as a bumped die.
Utilizing the Cool-Log Engine
According to ams, the star of this new sensor is its Cool-Log engine. When the sensor consumes 2µA of stand-by current, this engine can track temperatures for over a year on a 30mAh single-cell battery. ams said this engine will allow the sensor to function with “smaller and cheaper”, namely single- and dual-cell, batteries. The chip, ams said, “operates in passive mode and harvests energy from a reader’s incoming RF field, supplying external circuitry with a current of up to 3mA at 1.8V”.
At present, the AS39513 sensor is one of the few ams sensors that use the Cool-Log engine. The SL900A also utilizes the Cool-Log command set, as did the SL13A, which ams says the AS39513 “supersedes”.
Figure 2. A diagram of the AS39513. Image courtesy of ams.
Surpassing the SL13A
ams guarantees that the AS39513 operates at an accuracy of ±0.5°C between -20°C and 10°C, the required range for cold chain goods, and ±1°C in the extended range of -20°C to 55°C. Similarly, its predecessor, the SL13A, sported a nonlinearity of ±0.5ºC.
In a 2013 press release that details the release of the SL13A and the SL900A, ams said the sensors draw an average of 1.6µA in stand-by mode and have a “very long battery life.” ams announced the discontinuation of the SL13A in 2015 and noted that the AS39513 would be its substitute. They originally planned to have the AS39513 available for sampling in the first quarter of 2016 and mass production in the third quarter of the same year.
“Our SL13A Cool-Log pioneered the IoT in cold chain logistics, proving the technical and commercial viability of item-level tagging, or what we prefer to call the Curriculum Vitae of Things,” Cutrignelli told AAC. The AS39513 builds on what Cutrignelli believes the SL13A did well, adding full NFC compatibility.
The Future of Food Supply Technology
According to Cutrignelli, ams’ new sensor provides temperature accuracy that is “precisely what food and pharmaceutical markets demand.” In the company’s press release, he said the sensor “enables [users] to acquire detailed records of the temperature and other conditions in which a single package has been kept and, if necessary, reject the shipment.”
These potential shipments could include anything sensitive to heat or cold, namely medical supplies and perishable food products. In fact, in 2016, the FDA implemented the final rule in its Food Safety Modernization Act. The rule invokes heightened requirements of transported goods, which includes more stringent record-keeping and temperature control, something sensors like the AS39513 could help monitor.