The NFC chip
At the heart of every NFC tag, sticker or product is an NFC ‘chip’ or ‘IC’ (integrated circuit). These tiny electronic devices store your information and control how it can be accessed.
NFC IC types
Different NFC chips have varying amounts of memory and features. The amount of memory will determine how much data you can store on your chip. Additional features can include password protection, scan counters or tamper detection.
The price that you pay for your tags and products will be very closely related to the quantities being made. High volume manufacture reduces the pricing significantly and therefore most tag production tends to lean towards a very small selection of chips. In reality, the NTAG213, NTAG210 and MIFARE Ultralight chips are the most commonly available chips used with NFC tags. If you need another chip, then plan ahead and carefully check production costs.
Genuine vs. fake
Rule No. 4 : Unless the cost of replacing the tag is less than a few pence/cents, buy quality tags and genuine chips
The vast majority of NFC chips available on NFC tags and products sold via retailers and large scale tag manufacturers are made by NXP Semiconductors. There are however, a number of non-genuine chips around particularly with the Ultralight. NFC.Today very strongly recommend using genuine chips and making sure you know your supplier and where they make the tags. The reliability and quality of non-genuine chips varies between not great and truly shocking. There aren’t going to be many projects which will find the savings worthwhile.
Choosing your NFC IC
Let’s keep it simple.
Use either the NTAG213 or NTAG210µ (NTAG210 Micro), unless :
You need more memory. In which case your best option is usually the NTAG216. The 215 might be a little cheaper but it’s so rare that you probably won’t save much. There are a few other variants of large memory chips by other manufacturers and from NXP. However, these are typically expensive and difficult to get hold of unless you are buying in very large quantities. Our recommendation is to go with the NTAG216 (or 215) and try and work around that.
You need a product (wristband/keyfob). In which case, you might find more products available with the Ultralight chip. However, many Ultralight products have fake chips and can be very low quality. Purchase carefully from a good supplier and make sure you clearly specify you want genuine NXP chips. Some other products, such as PVC cards or more industrial NFC tags, are now commonly available with NTAG chips. You may find that the price is slightly higher than using Ultralight but that can often be because the Ultralight variant is not a genuine NXP chip.
You need tamper or authentication features. Then go for the NTAG213 TT or NTAG413 DNA. There isn’t much choice on the tamper detection unless you are in the market for hundreds of thousands of tags.
Rule No. 1 : More memory doesn’t give you better performance. In fact, quite the opposite, don’t use a chip with any more memory than you need.
NFC.Today take the view that the NFC tag should be an ID and link to data on the internet or ‘in the cloud’ rather than the store of data itself. In which case, the standard NTAG210µ/NTAG210 or NTAG213 should be more than enough even for longer tracking URLs or a simple ID. You can use our NFC Tag memory calculator to check which chip you might need. We also have a quick reference guide on how much NFC tag memory you might need.
If you do need to start storing data on the tag itself, perhaps because there might not be internet access when the tags are scanned, then the larger NTAG215 or NTAG216 chips can help. However, be careful. Many NFC projects find even these can be restrictive and it must always be considered that all NFC tags have a very limited memory capacity. You also need to make sure that your App or system is reliable as there have been reports of timeout and other errors when storing large datasets to the larger chips from a mobile phone.
It’s also worth bearing in mind that the larger NTAG215/216 chips and other similar variants are substantially more expensive than the more common versions. Additionally, supply and general availability is much lower. Some other alternative chips, such as the MIFARE Classic, are not NFC Forum compatible so that also needs to be considered.
In summary, we cannot recommend strongly enough that you should use the tag as an ID or link to internet based data. It’s a far more flexible and cost-effective way to go.
Popular NFC Chips
NXP’s NTAG series along with their Ultralight chip are by far the most common for mobile use. The basic details are listed here and there’s a breakdown of each of these features and chips below.
|Chip||Memory||User Memory||Max URL||Scan Counter||Password||Auth|
|MIFARE Ultralight EV1 (80byte)||80||48||40||✓|
|MIFARE Ultralight EV1 (164byte)||164||128||120||✓|
Memory vs. user memory
Memory is the total amount of memory within the chip. Worth noting that relative to other memory devices such as USB sticks, etc, this is very, very small. In fact, most NFC tags can store no more than roughly a single sentence of text. However, within that memory space there are sections which are reserved for the function of the tag. For example, information regarding permission to change the data, the UID of the chip (which can’t be changed on genuine chips), and so on. This means that a user wishing to store data onto the tag can’t use all the available memory space and only the space minus this important data – the ‘user memory’.
To make it easier to understand what can actually be stored in this user memory space, the table shows the maximum length of a URL (web address) that can be stored on that tag. This is the number of characters in your web address without the ‘https://’ or ‘https://www.’ part. Use our NFC tag memory calculator to find out which chips you might be able to use.
*Note that for the NTAG203 and NTAG213, we’ve used available memory by excluding the encoding of a lock control TLV for dynamic lock bytes. These would take an additional 5 bytes but if dynamic locking is not required (it’s extremely rare that it is), then these 5 bytes can be used to increase the possible length of the URL.
Some NFC tags reserve a small amount of memory and have a feature which allows the tag to automatically store how many times it has been scanned. Note that if you are using the tag to count the number of visits to, say, a web page, then this isn’t a good way to do it. It is possible for a user to scan the tag, increase the count, but not visit the URL stored on the tag. For example, maybe the user didn’t have internet access or cancelled the pageview before the page got a chance to load. In this instance, the scan count will increase at a higher rate than the number of actual page views resulting in incorrect data. The scan counter tends to be more useful for certain security or monitoring applications than for marketing.
Some NFC tags have a password feature which allows controlled access to view or change the data on the tag. From a mobile phone, an App is required for this. It’s a fairly low level of security but would stop a casual viewer changing data.
The new NTAG413 DNA tag contains a special feature allowing sections of data to be encrypted and securely appended to the URL of the tag. This then allows the tags to be used for NFC Tag authentication where the tags cannot easily be replicated. It’s a very advanced feature and requires substantial knowledge to both encode the tags and to authenticate the tags. However, the NTAG413 DNA is one of the first chips in the latest generation of authentication tags and we’d expect to see more variants soon.
All the NTAG series and the MIFARE Ultralight® chips have a common set of features such as a seven byte (14 character) unique ID (UID), universal compatibility across all current mobile phones, tag locking ability and NFC Forum compatibility.
Other NFC chips
Obviously, the NTAG and MIFARE Ultralight® chips aren’t the only NFC chips on the market. And of course, NXP isn’t the only manufacturer with companies such as Infineon and STMicroelectronics also making NFC chips.
The reason NFC.Today tend to focus on the NTAG series is simply because they are the most widely available and universally compatible. Some of the other chips, such as the MIFARE Classic® for example, are not NFC Forum compatible. Most of the others would only be available as a specialist order in very high quantities.
MIFARE, MIFARE Ultralight, MIFARE Classic and MIFARE DESFire are registered trademarks of NXP B.V.