NFC front end with Active Boost technology gains design win in payment card
DeviceFidelity Inc., is using the ams RF technology along with an integrated antenna in its CredenSE 2.10 Near Field Communication (NFC) microSD card to enable secure, certified NFC transmissions between any mobile phone and contactless payment terminals from Visa and MasterCard.
The product is the world’s first NFC microSD card to achieve global payment certifications from both Visa and MasterCard without requiring external booster antenna or device specific attachments. Using the AS3922 from ams, an integrated NFC front end with Active Boost technology, CredenSE achieves a typical read range of 4cm when located in a mobile phone’s microSD slot.
The mobile phone is a notoriously difficult environment for RF and variations between phone models make it difficult to consistently achieve good performance. The stringent requirements for read range compatibility with payment terminals for payment applications cannot be met in small form factors such as SIM or microSD cards with a traditional passive NFC card emulation front end and simple planar antenna.
Earlier SIM and microSD designs therefore used an additional component such as an external booster antenna or external attachment to amplify RF communication between tag and reader. The use of such external antennas makes mass deployment impractical since it raises bill-of-materials while also increasing the complexity of handling distribution and support for a variety of different handset models.
The DeviceFidelity CredenSE 2.10 is the first commercially produced NFC microSD card that meets EMV standards using only an ultra-small antenna embedded in the card, making distribution and compatibility with hundreds of phone models possible with one easy-to-deploy microSD card.
This means that it can be used to transform any mobile device with a microSD card slot into a contactless payment device without any need for device specific external antenna or attachments. DeviceFidelity has been granted global patents for the design and functionality of such an NFC microSD with built-in antenna and active front end.
The certified solution has been achieved primarily through the use of the Active Boost capability in the AS3922, working in conjunction with a DeviceFidelity-designed 3D miniature antenna, which actively transmits in response to a point-of-sale reader, in contrast to the passive load modulation normally supported by NFC tags.
Active Boost allows for robust tag-to-reader communication at a coupling factor 100 times higher than is possible with conventional passive tag designs. The AS3922 also offers unique Antenna Auto Tuning and Q factor adjustment, which are critical to microSD, SIM and µSIM applications. The IC includes an ACLB interface for communication with the contactless interface of any Dual Interface Secure Element, and DCLB and NFC-WI interfaces for digital communication.
Use of the AS3922 with a 3D antenna also eliminates the need for the user to hold the phone in any orientation.