ST published two new NFC/RFID calculators in eDesign Suite. The UHF Link Budget helps designers understand the range they can obtain from their RFID reader. The NFC Tuning Circuit enables engineers to optimize their NFC reader design around the ST25R3911B or the ST253916. Both make the creation and optimization of contactless applications accessible by empowering companies, students, enthusiasts, and more. The two web applications also benefit from a straightforward interface. Users enter parameters, run simulations, get schematics, and anticipate performance. Many teams use spreadsheets with the most common formulas to help them design their RF circuit. The NFC/RFID calculators are like these Excel documents, but in an open format and with power-user features.
What Is eDesign Suite and NFC/RFID Calculators?
eDesign Suite tools reduce friction and make designing circuits more intuitive. Some solutions facilitate the design of power supplies, while others offer thermo-electrical simulations or signal conditioning design tools. Users enter key parameters and obtain schematics or other design recommendations. Many utilities help teams find suitable devices and define bills of materials. Some of them also offer graphs or a console to simulate conditions or behaviors. ST recently overhauled the web utility to make it more responsive and intuitive. We also added export features to PSpice to integrate eDesign Suite into more workflows.
What Is the NFC Inductance Calculator?
Since the early days of eDesign Suite, one of its most powerful utilities was the NFC Inductance calculator. The form helps design antennas for readers and tags even if users are not relying on ST devices. Indeed, one core principle behind the NFC/RFID calculators is the desire to help the community at large. Whether it is to assist researchers1, 2 or engineers working on any devices, the NFC Inductance calculator helps create contactless solutions faster and more effectively. In a nutshell, users enter the antenna’s geometry values, and the tool computes the expected inductance, which is the key parameter for antenna resonance frequency calculation. It also throws a warning if the antenna parameters could lead to errors.
What Is the NFC Tuning Circuit
Originally, NFC Tuning Circuit was an executable downloaded on our website. However, to make it more accessible, ST turned it into a web application and added it to the NFC/RFID calculators. Users choose between the ST25R39xx that matches their device and a configuration type, such as single-ended or differential, and the tool spits out the relevant matching network. The schematics include the capacitors and resistors needed. Users can also fine-tune the performance, and the console offers performance data. As a result, NFC Tuning Circuit answers many questions engineers have before testing their product in the field. Moreover, developers can also work backward by defining their target impedance and seeing what they need.
What Is the UHF Link Budget?
UHF Link Budget is one of the new UHF RFID calculators. It helps developers determine the range between the tag and the reader. The measurement depends on many variables, from antenna characteristics to tag type, among other specifications. Moreover, developers can enter the range they want to obtain, and the wizard computes the hardware requirements. For instance, engineers needing a reliable range of about three meters will enter six meters in the application to allow some headroom and find whether their prototype matches the results from the UHF Link Budget. The default carrier value is 915 MHz to reflect regulatory imperatives in North America. However, developers can change it to the frequency matching their region.
What’s Next?
ST will continue updating those calculators and creating more tutorials to help engineers take advantage of them. The goal is to empower the community to design more accurate systems faster, reduce frictions, and shorten the time to market. The NFC Tuning Circuit should also support additional ST25 reader devices in the future.
- Try one of the eDesign Suite NFC/RFID Calculators
- Explore ST’s educational content on NFC Technology
- How NFC can solve connectivity challenges in smart monitoring
- Awate, Rehan & Rathod, Ravi. (2017). Near field Communication using M24LR16. ↩
- Peres C, Emam M, Jafarzadeh H, Belcastro M, O’Flynn B. Development of a Low-Power Underwater NFC-Enabled Sensor Device for Seaweed Monitoring. Sensors. 2021; 21(14):4649. https://doi.org/10.3390/s21144649 ↩
