As electronica 2018 opens its doors, ST will hold its first demo of an NFC reader compatible with the EMV Contactless interface specification v3.0 (EMVCo 3.0). Our new component will officially launch early next year, but we are already previewing it during the event because the upcoming protocol will bring serious changes to the way manufacturers certify their terminals and vendors accept payments. It was thus important for us to put our partners at ease by demonstrating how we already tackled the new challenges inherent to the EMVCo 3.0 certification. Indeed, according to the current unofficial industry estimates, the standard could be a mandatory requirement for vendors by Q3, 2019. It is thus also imperative to show that a fast transition to the new standard is not only possible but relatively easy to achieve thanks to our new part number.
EMV was originally the acronym for Europay, Mastercard, Visa, the companies behind the standard’s first version in 1994. As more payment companies and financial institutions joined, EMV became EMVCo, a global consortium that supervises the development and adoption of standards regulating card payments, whether it be through a magnetic strip, a chip, or contactless technologies. They not only oversee the major technical specifications of the various standards but define the testing and certification process to ensure that devices are truly compliant. As more payment methods appeared with smartphones and smartwatches, the EMVCo’s new mission became to guarantee flawless interoperability between all these solutions to ensure a better user experience for vendors and consumers. EMVCo is thus releasing EMV Contactless interface specification v3.0 to better answer the new challenges arising from the new NFC transmitters that the public uses to purchase goods and services.
1. New PICC Reference Profiles
The first significant difference between EMVCo 2.6 and EMVCo 3.0 is the presence of three reference PICC (Proximity Integrated Circuit Cards) instead of just one. A PICC reference simulates a payment card to test a reader’s compatibility with the current standard. By adding multiple PICC references, EMVCo can guarantee better interoperability of terminals interacting with phones and cards. Very simply, there are two levels of EMV certifications. EMV Contactless Level 1 ensures that the terminal meets the fundamental electromagnetic and communication protocol requirements while Contactless Level 2 focuses on the software validation that implements the payment functionalities which run on Level 1 devices.
Under EMVCo 2.6, the Contactless Level 2 certification originally ensured interoperability between readers and the mobile devices or cards. However, under certain use cases, it was possible to pass the first level and still have issues during Level 2 tests. Hence, by demanding that readers be compatible with these additional two PICCs, EMVCo 3.0 now protects users against the interoperability issues that plagued EMVCo 2.6.
2. New Matching Frequencies and Loads
Another fundamental aspect of the new standard is that each reference PICC requires tests with two different loads. On top of the original credit card size PICC tuned to 16.1 MHz, EMVCo 3.0 now mandates tests for two additional PICCs tuned to 13.56 MHz, one using a traditional credit card size and the other using a design that’s about half the size to account for the smaller antennas of mobile terminals like smartwatches. Moreover, the new standard adds two loads per PICC, meaning that the terminal must be tested twice for each of the cards.
Moving to the new standard will thus require substantially more testing because instead of a single PICC reference, companies must now run six simulations. Hence, the industry is facing an uphill battle because the new standard, though necessary, makes designing a payment terminal more complex since correcting its antenna for one PICC profile may result in a new incompatibility with the other five.
3. Better Signal Quality
Finally, EMVCo 3.0 places much more stringent regulations on the overshoot and undershoot limits. When a reader tries to couple with a PICC, there is always be a back and forth of energy. If we look at the waveshape of the signal on the antenna, it takes the form of an overshoot and an undershoot, until the reader and PICC match. In EMVCo 2.6, terminals had an overshoot and undershoot allowance of about 10 %, whereas EMVCo 3.0 now limits it to between 5 % and 10 %, depending on the rise/fall times. Such restrictions will ensure a better signal, but it means that dealing with the new PICC references and all six possibilities is even more difficult than before.
Active Waveshaping: One of Our Answers to EMVCo 3.0
The first solution to these challenges is our new Active Waveshaping (AWS) mechanism on our upcoming ST25R3916, the successor to the ST25R3911B, which was our most flexible and powerful reader. Our previous generation of devices had an output driver that simply switched on or off while the AWS can adjust the signal for RF compliance. It will thus be able to tweak the voltage and therefore the energy at the antenna in tiny time segments to better match all the PICC references and stay within the new waveshape requirements. Moreover, the Dynamic Power Output (DPO) that was already present in the ST25R3911B family of readers still controls the field strength automatically to stay within the strict EMVCo minimum and maximum limits. This will be a particularly important feature to dynamically adjust the field strength to match all six PICC references.
The market also demands even smaller terminals with their antenna close to the LCD. A standard receiver can easily mistake the noise emitted from the screen for the load modulation of a card. As a result, POS (Point of Sale) terminal suppliers need to purchase low noise (shielded) LCDs. However, the ST25R3916 now sports a noise suppression receiver, which makes the ST25R3916 exceptionally noise resistant, thus allowing for more practical designs while also giving manufacturers a wider choice of compatible LCDs.
Toward a Better User Experience
We will also be showing an EMVCo reference design kit at the Trustech Conference, at the end of November, to show the spirit behind all these new changes. Interoperability wasn’t the only issue that the EMV Consortium was trying to solve. A bad overshoot or a lack of compatibility with the latest mobile payment solutions can lead to errors or bad performances. A bad analog performance also means that devices need to be closer or that the smallest change in positioning can cause failures. However, thanks to ST25R3916, POS terminal suppliers will have the assurance that they can more easily pass the new EMVCo 3.0 certifications and offer a better experience to the final user.
The new ST25R3916 reader will be in preview at Electronica for more general-purpose applications
