The ICODE SLIX-L is the reduced-memory version of the SLIX generation from NXP Semiconductors, the replacement for the ICODE SLI-L, designed for high-volume object identification with a strong focus on privacy: factory automation, industrial and laundry, asset management, libraries and rental. Compliant with the ISO/IEC 15693 standard (known as vicinity) and compatible with the NFC Forum Type 5 format, it offers 32 bytes of user memory along with privacy and destroy modes. It can be read and written by the vast majority of recent NFC smartphones.
Information
| Manufacturer | NXP Semiconductors |
| Family | ICODE (SLIX generation) |
| References | SL2S5002 and SL2S5102 |
| Standard | ISO/IEC 15693 (vicinity cards) |
| NFC Forum type | Type 5 Tag compatible |
| Operating frequency | 13.56 MHz |
| Data rate | Up to 53 kbit/s |
| Unique identifier (UID) | 8 bytes (64 bits), factory programmed |
| Operating distance | Up to 1.5 m with a long-range reader; a few centimeters with a smartphone |
| Data retention | 50 years |
| Write endurance | 100,000 cycles |
| Total memory (EEPROM) | 64 bytes (512 bits) |
| User memory | 32 bytes |
Memory
The EEPROM memory of the ICODE SLIX-L is organized into 16 blocks of 4 bytes; only the 8 user blocks can be addressed with the read and write commands:
| Area | Content | Access |
|---|---|---|
| Configuration area | 64-bit UID, passwords, locks, AFI, EAS and DSFID | No direct access; managed through dedicated commands |
| Blocks 0 to 7 | User memory (32 bytes) | Read / write, lockable block by block |
In practice, the 32 bytes of user memory only leave room for a minimal NDEF record: a URL of around 20 characters once the Capability Container (written into the first block during formatting) and the NDEF envelope are taken into account. The chip is primarily designed for identification through its UID, with most of the information residing on the system side; for a consumer NFC tag intended to hold a link, an NTAG213 remains the appropriate choice.
Features & security
- Privacy mode: the Enable Privacy command silences the chip (it only responds to the Get Random Number and Set Password commands) until the 32-bit privacy password is presented, in order to protect the holder's privacy.
- Destroy command: protected by a 32-bit password, it disables the chip permanently and irreversibly; it will never respond to any command again.
- Protected EAS and AFI: the EAS anti-theft feature (with its identifier for selective alarm) and the AFI filtering are covered by the 32-bit EAS/AFI password, with a protection that is enabled separately and irreversibly, a capability the SLI-L did not offer for the AFI.
- Locking and inventory: irreversible block-by-block locking (AFI, DSFID and EAS can also be locked) and multi-tag inventory with page reading during anticollision.
- Symmetrical range: the write distance is equal to the read distance, an asset for encoding tags on the fly on a logistics line.
The ICODE SLIX-L is limited to three passwords (privacy, destroy and EAS/AFI) and does not offer the memory read and write passwords of the ICODE SLIX-S. The chip comes in two antenna tuning versions, SL2S5002 (23.5 pF) and SL2S5102 (97 pF) for small labels.
Compatibility
The ICODE SLIX-L uses NFC-V technology (ISO/IEC 15693), supported by the vast majority of recent NFC smartphones. On Android, reading and writing work natively with NFC Tools, without any particular restriction. On iPhone, automatic background reading is available from the iPhone XS and XR onwards; models from the iPhone 7 can read and write the chip via NFC Tools on iOS 15.6 or later, by starting the scan manually from the app.
With NFC Tools, the ICODE SLIX-L chip supports reading technical information, writing records, erasing and permanent locking. The passwords are managed through the chip's dedicated commands. The list of compatible models is available in the article on compatibility.
ICODE SLIX-L vs SLIX vs SLIX-S
| Chip | User memory | Security | Typical use |
|---|---|---|---|
| ICODE SLIX-L | 32 bytes | Privacy, destroy, protected EAS and AFI | High-volume identification, privacy |
| ICODE SLIX | 112 bytes | EAS and AFI protectable by password | Libraries, general logistics |
| ICODE SLIX-S | 160 bytes | Five passwords, privacy, destroy | Secured supply chain |
All three chips share the ISO/IEC 15693 protocol, the 50-year data retention and the same smartphone compatibility. The SLIX-L favors cost and privacy with minimal memory; the SLIX is the versatile choice of the generation; the SLIX-S adds the memory read and write passwords. The ICODE SLIX2 completes the range with the largest memory.
Frequently asked questions
How much data can be stored on an ICODE SLIX-L?
The chip has 32 bytes of user memory, which corresponds to a URL of only around 20 characters once the Capability Container and the NDEF envelope are taken into account. It is primarily designed for identification through its UID rather than for storing content.
What is the privacy mode for?
Once enabled, it silences the chip: it no longer responds to any command, except the random number request and the presentation of the privacy password. This mode protects the holder's privacy, for example for a rented item or a textile in a laundry between two cycles.
Is the ICODE SLIX-L compatible with iPhones?
Yes. Background reading works from the iPhone XS and XR onwards, and both reading and writing are possible via NFC Tools from the iPhone 7 on iOS 15.6 or later.
Can an ICODE SLIX-L be protected against rewriting?
A permanent, irreversible lock is possible block by block, including from NFC Tools. The chip does not offer a memory write password: for that feature, the ICODE SLIX-S is the chip to consider.
Useful links
