UHF Recommendation 
Impinj M700
For retail, inventory and item-level tagging.
Security PWD
Memory 96–496 bit EPC
NXP UCODE® DNA: Technical Data, Security and Use
NXP UCODE® DNA is a passive UHF RFID chip for RAIN RFID applications. It supports GS1 UHF RFID Gen2 v2.0 and AES-based authentication according to ISO/IEC 29167-10. The chip has 224 bits of EPC memory, a factory-locked 96-bit TID and, depending on IC version and configuration, up to 3,072 bits of user memory.
UCODE DNA is aimed at applications in which the range of UHF is to be combined with cryptographic tag authentication. NXP names automatic vehicle identification, asset tagging, access management as well as inventory and supply chain management, among others. NXP still lists SL3S5002N0FUD with the product status “Active”.
| Feature | Value |
|---|---|
| Manufacturer | NXP Semiconductors |
| Product family | UCODE® DNA |
| Type designation | SL3S5002N0FUD |
| RFID class | UHF / RAIN RFID |
| Frequency | 860–960 MHz |
| Standard | GS1 UHF RFID Gen2 v2.0 |
| Security standard | ISO/IEC 29167-10 |
| EPC Memory | 224 bits |
| User Memory | Up to 3,072 bits, depending on IC version and configuration |
| TID | 96 bits, factory-locked; includes 48-bit serial number |
| Authentication | AES-based cryptographic tag authentication |
| Encryption | AES-128 for authentication; no encryption of user data specified |
| AES keys | Up to two 128-bit AES keys |
| Access password | 32 bits |
| Kill password | 32 bits |
| Privacy | Untraceable function according to GS1 UHF RFID Gen2 v2.0 |
| Memory protection | BlockPermalock |
| Anti-collision | Yes, according to the UHF RFID Gen2 protocol |
| Read Sensitivity | −19 dBm |
| AES Authentication Sensitivity | −18 dBm |
| Write Sensitivity | −11 dBm |
| Read range | Application-dependent; NXP specifies up to 15 m with suitable tag and reader configurations |
| Write cycles | At least 100,000 |
| Data retention | 20 years |
| Operating temperature | −40 °C to +85 °C |
| Smartphone NFC | No, not directly via the NFC interface |
| Product status at NXP | Active |
| Typical media | UHF label, RFID label, hard tag, windshield label and special transponders |
| Security rating | AES-128 |
| Recommendation | Track and trace and identification with increased requirements for tag authentication |
Technically, UCODE DNA differs from simple UHF tags primarily in its AES-based authentication. The chip also supports a 32-bit access password and a 32-bit kill password, BlockPermalock and the Untraceable command of the Gen2 v2 standard. NXP specifies a read sensitivity of −19 dBm, an AES authentication sensitivity of −18 dBm and a write sensitivity of −11 dBm.
Typical Applications
UCODE DNA is suitable for applications in which objects or vehicles are to be identified over a greater distance and a pure EPC identifier is not sufficient as a security feature. The official NXP product page names several fields of application.
- automatic vehicle identification
- asset tagging
- access management
- inventory management
- supply chain management
- baggage tagging
- brand protection and authenticatable product labeling
Particularly suitable media are UHF labels, RFID labels and application-specific hard tags. For vehicle applications, NXP names windshield labels and electronic license plate carriers, among others. The actual read range depends heavily on antenna, tag construction, reader, transmission power and environment. NXP specifies up to 15 meters for suitable reference applications.
Security
Security level: High
UCODE DNA adds cryptographic authentication with AES-128 to the usual access functions of a UHF tag. NXP describes up to two 128-bit AES keys protected in the IC. This allows a reader to check whether a tag possesses the expected cryptographic secret instead of relying only on the EPC or TID as an identification feature.
The implementation is based on GS1 UHF RFID Gen2 v2.0 and ISO/IEC 29167-10. For privacy, the chip also supports the Untraceable command, which can be used to restrict readable identification information depending on the configuration. The access password and kill password are each 32 bits long.
However, AES authentication does not automatically prevent every form of tracking or misuse. Key management, reader configuration and backend are decisive. For this purpose, NXP offers Trust Provisioning, among other things, in which individual passwords and cryptographic keys can be derived and injected into the chip during manufacturing.
For pure stock and inventory applications without cryptographic authentication, simpler UHF chips may be sufficient. UCODE DNA is particularly relevant when a UHF tag is also to be verified cryptographically or its readable data is to be controlled.
Advantages and Disadvantages of NXP UCODE DNA
| Advantages | Disadvantages |
|---|---|
| AES-128-based tag authentication | Higher unit price than simple UHF tags |
| Up to 3,072 bits of user memory | AES functions require suitable reader and backend support |
| Untraceable function for additional privacy protection | Not directly readable with smartphone NFC |
| BlockPermalock for permanently write-protected memory areas | Read range highly dependent on antenna, reader and environment |
| At least 100,000 write cycles and 20 years of data retention | Key management increases the integration effort compared to simple EPC tags |
Alternatives to NXP UCODE DNA
Depending on security requirements, memory needs, read range and costs, other chip types may be better suited.
UHF 
Alien Higgs-9
For asset tracking, automotive, aviation and mass tagging with additional user memory.
Security PWD
Memory 96–496 bit EPC
HF / NFC Recommendation 
MIFARE DESFire EV3
For secure company ID cards and multi-application cards with a short read distance.
Security AES-128
Memory 2 / 4 / 8 / 16 KB
Frequently Asked Questions about NXP UCODE DNA
How much memory does NXP UCODE DNA have?
The current NXP product page states 224 bits of EPC memory, a factory-locked 96-bit TID and, depending on IC version and configuration, up to 3,072 bits of user memory. In addition, the chip has memory for the 32-bit access password and the 32-bit kill password as well as internally protected cryptographic keys. EPC memory, TID and user memory serve different purposes and should therefore not be added together to give a supposed total memory.
How secure is NXP UCODE DNA?
UCODE DNA supports AES-based tag authentication. NXP describes two 128-bit AES keys that can be stored in protected memory of the IC. Authentication follows the mechanisms provided for this purpose in GS1 UHF RFID Gen2 v2.0 and ISO/IEC 29167-10. UCODE DNA therefore has a significantly different security architecture than simple UHF tags, which essentially work with EPC, access password and kill password. Nevertheless, the security of the entire application depends on key management, reader and backend.
Can NXP UCODE DNA be read with a smartphone?
Not directly with a smartphone's usual NFC module. UCODE DNA is a UHF or RAIN RFID chip, not an NFC tag. Reading requires a reader that supports the regional UHF frequency range used and GS1 UHF RFID Gen2. If a smartphone is to be part of the application, an external UHF reader or a corresponding system solution is usually required.
Which readers support NXP UCODE DNA?
The basic requirement is a UHF RFID reader for GS1 UHF RFID Gen2 v2.0 or the corresponding RAIN RFID communication. If AES authentication is also to be used, the system side must support the Authenticate function and the key concept used. A reader that can only inventory ordinary EPC Gen2 tags therefore does not automatically use the security functions of UCODE DNA.
What is the read range of NXP UCODE DNA?
There is no fixed read range, because it depends on the finished transponder and the reader system. NXP cites applications with read ranges of up to 15 meters for UCODE DNA. The original UCODE DNA fact sheet gives examples of up to 15 meters for an electronic license plate carrier and 10 meters for a windshield label. These values are not a general guarantee for every UCODE DNA label. Antenna, installation location, reader power and environment influence the actual read range.
What is the difference between NXP UCODE DNA and Impinj M700?
Both belong to the UHF RFID range, but have different focuses. The Impinj M700 series is geared toward retail, inventory and item-level tagging and works with a 96- or 128-bit EPC and password protection. UCODE DNA, on the other hand, is positioned for track and trace with increased security requirements and adds AES-128-based authentication to the UHF functions. The decisive factor for the selection is therefore whether ordinary identification is sufficient or the tag is to be cryptographically authenticated.
Can the memory of NXP UCODE DNA be permanently locked?
Yes. UCODE DNA supports BlockPermalock, which allows designated memory blocks to be permanently locked against further changes. In addition, there is a 32-bit kill password with which a tag can be permanently deactivated. Since both functions can have irreversible effects, they should only be used within a defined encoding and key concept.
Is NXP UCODE DNA still being produced?
Yes. NXP currently lists the type SL3S5002N0FUD with the status “Active”. This should be distinguished from UCODE DNA Track with the type designation SL3S5050N0FUD, which NXP now labels as “No Longer Manufactured”. For procurement and system planning, the exact type designation should therefore be checked and not just the name “UCODE DNA”.
Request RFID Media with NXP UCODE DNA
Do you need UHF labels, RFID labels or special transponders with NXP UCODE DNA?
For the selection, media format, quantity, operating environment, desired read range, existing UHF reader and requirements for EPC encoding and AES authentication are particularly relevant. For existing systems, it should also be checked which Gen2 v2 and security functions the reader supports.
Technical sources
Data as of: September 2026
The technical information is based on the current NXP product page for UCODE® DNA: UHF Tag IC for Secure Authentication, SL3S5002N0FUD, which NXP currently lists with the product status “Active”, and on the NXP fact sheet UCODE DNA tag IC – A breakthrough in RAIN RFID security, document 75017646, Rev. 0 dated 15 November 2016. For the classification of the variants, the current NXP product information on UCODE DNA Track was also used.
The information on GS1 UHF RFID Gen2 v2.0, AES authentication, ISO/IEC 29167-10, memory, write cycles and data retention comes from the NXP documents mentioned. No newer complete public data sheet for UCODE DNA is currently listed on the public product page; NXP provides product information, a brochure and an application note there.
Trademark notice
NXP, the NXP logo and UCODE are trademarks of NXP B.V.