Texas Instruments Unveils NFC RFID Sensor Chips, Demo Kit

The new ICs come with a built-in microcontroller and a temperature sensor, and are designed for developers of RFID transponders, as well as appliances or other types of electrical devices.
Published: December 10, 2014

Semiconductor firm Texas Instruments (TI) has released an evaluation version of a new family of RFID chips designed to deliver sensor-based data via a Near Field Communication (NFC) reader. The new series of transponder chips, known as RF430FRL15xH, is intended for industrial, medical and logistics applications. Several companies are now building prototypes of products and solutions based on the chips, though none are yet willing to be named.

The ICs, which operate at 13.56 MHz and are compliant with the ISO 15693 standard, each come with a built-in temperature sensor and a programmable microcontroller (MCU), and also have an analog-to-digital converter (ADC) to allow connection to a variety of other sensors, such as moisture, pressure, light or motion. The chip, which measures 4 millimeters by 4 millimeters (1.6 inches by 1.6 inches), can operate in passive mode, powered by a signal transmitted by an NFC RFID reader, as well as in semi-active mode, powered by a 1.5-volt battery.

TI’s Diwakar Bansal

The chip’s onboard non-volatile fast-access user memory (FRAM) is intended to allow developers to create transponders or electrical devices that store sensor data on the chip. This enables configuration according to the needs of a particular application, such as setting the device to issue alerts under specific conditions.

A version of the chip is also available with SPI and I2C interfaces, either of which can be used to connect both digital and analog sensors to the chip. In addition, the interface can be utilized to connect the chip to a microcontroller or a microprocessor that is part of the electronic device in which the chip is installed. Doing so enables additional functions, such as forwarding data from that device to a cloud-based server via an NFC reader.

The RF430FRL152H includes all sensor functionality described above, while the RF430FRL153H model comes without the SPI/I2C interface. The RF430FRL154H version does not include the ADC.

Texas Instruments has been working on the new transponder for some time, says Diwakar Bansal of TI’s strategic marketing department, and has tested it with its own developers in-house. This week, the company is offering the product for sampling by developers with sales in large numbers expected by early next year. TI is working with developers that are now creating prototypes of applications using the new chip, Bansal reports. Beginning in January 2015, and at the Consumer Electronics Show (CES), in Las Vegas, some of those prototypes will be ready for customer demonstrations. He predicts it will be several months before the products become commercially available.

The firm began developing the chip to meet the needs of its customers—both developers and end users—who have indicated that they wanted a low-power technology to easily collect and share sensor-based data from a variety of tagged items or individuals. In fact, he says, developers have already suggested innovative ideas around the development of systems using the transponder to collect sensor-based data to track patients’ heath.

In the health-care sector, for instance, the RF430FRL15xH series chip can be built into disposable patches that are affixed to a patient’s skin. The transponder’s built-in sensor could detect that patient’s skin temperature and forward that data to an NFC reader built into a smartphone. The information could then be shared with authorized parties, such as that person’s physician.

The RF430FRL152Hsensor RFID NFC chip

For applications in which the RF430FRL15xH chip operates in passive mode, the power from an NFC reader’s RF transmission would energize the IC and cause it to collect sensor-based data and forward it back to the reader. If a user wanted to employ the technology to collect periodic sensor readings and store that information in its built-in memory (as a data logger would do), the transponder would require a 1.5-volt battery, but it would awaken its transmission functionality only upon receiving a transmission from a reader, and then transmit all of the data it has collected in its memory.

If a medical clinic wished to track data other than temperature, such as a patient’s hydration level, a sensor for that function could be connected to the RF430FRL15xH chip. It could then be encapsulated into a single patch that could be attached to that person’s skin, or be built into something like a wristband or watch. The patient could use his phone’s RFID reader to collect the data and forward it to a cloud-based server that the clinic could access with his permission. What’s more, the technology could be used in the clinical environment itself, as an alternative to thermometers or other medical measuring devices. Because there is a unique ID number encoded on each RF430FRL15xH chip, Bansal notes, the system could also be used at a clinic or hospital to not only collect sensor data, but also confirm the identity of the individual who was linked to that ID in the facility’s software system.

In an industrial setting, the system would allow workers to capture sensor data in places where they could not physically access the sensors themselves. In this case, sensors could be attached to machinery, manufacturing equipment or materials in such a manner that physically looking at a sensor’s screen would be impractical or unsafe. In such a scenario, a user could simply bring an NFC-enabled phone within read range of the transponder to collect the necessary data.

For an Internet of Things application, in which multiple sensor devices might be sending data to a server via a Wi-Fi connection, the transponder device’s NFC functionality would make it possible for someone in an industrial setting, such as on a factory floor, to capture data in real time while in front of a specific item to which a sensor is attached, and to view those results on the phone. This could be useful if that individual lacked immediate access to the server, or if the Wi-Fi network were to go down temporarily.

There are a variety of other use cases as well, Bansal adds, including the installation of transponders in car engines to track temperatures for vehicle operators. For logistics applications, the transponders could be placed within containers of temperature-sensitive cargo during transport, such as in boxes of fresh produce being delivered to stores.

The Sensor Hub BoosterPack includes a motion sensor, a gyroscope, an accelerometer, a compass, and pressure, humidity and light sensors.

The programmable MCU can also be used to set specifications for the transponder’s use. This includes setting up thresholds for temperature readings that would prompt the transponder to issue an alert if those temperatures became too high or low.

The chip can communicate either via the ISO 15693 or ISO 18000-3 air-interface protocol. That differs from other NFC tags and transponders that employ the air-interface protocol specified by the ISO 14443 standard. TI opted to use the ISO 15693 standard, Bansal explains, because it offers a longer read range than ISO 14443.

The RF430FRL152 offers greater built-in functionality than any other NFC transponder compliant with ISO 15693, Bansal adds. That functionality, he says, “will allow developers to bring products to the market very easily.”

The RF430FRL152HEVM development kit costs $19.90 at the TI store, while the transponder chip alone, also available for purchase in small quantities, is priced at $2.50. The kit consists of the chip, as well as a Sensor Hub BoosterPack that can be plugged into the chip to provide a motion sensor, a gyroscope, an accelerometer, a compass, and pressure, humidity and light sensors. It also comes with a built-in PC Host graphical user interface (GUI) for configuration and demoing.