The LRI2K is a historical NFC chip from STMicroelectronics: a member of the manufacturer's first generation of long-range contactless memories, it equipped item labeling, logistics, access control and industrial traceability long before the arrival of the ST25 range, to which it is now attached. Compliant with the ISO/IEC 15693 and ISO 18000-3 Mode 1 standards, it offers 256 bytes of EEPROM lockable block by block, a kill code for permanent deactivation and inventory commands optimized for moving tags. Its modern heir is the ST25TV02K; it remains readable and writable by the vast majority of recent NFC smartphones.
Information
| Manufacturer | STMicroelectronics |
| Family | LRI (first generation, attached to the ST25 range) |
| Reference | LRI2K (sometimes listed as ST LRI2K) |
| Standard | ISO/IEC 15693 and ISO 18000-3 Mode 1 (vicinity cards) |
| NFC Forum type | Type 5 Tag compatible |
| Operating frequency | 13.56 MHz |
| Data rate | Up to 53 kbit/s (fast commands) |
| Unique identifier (UID) | 8 bytes (64 bits), factory programmed |
| Tuning capacitance | 21 pF or 97 pF depending on the version |
| Operating distance | Long range with a dedicated RFID reader; a few centimeters with a smartphone |
| Data retention | 40 years minimum |
| Write endurance | 1,000,000 cycles minimum |
| User memory | 256 bytes (2,048 bits) |
Memory
The memory of the LRI2K is exemplary in its simplicity: 64 blocks of 4 bytes, all dedicated to the user and always readable, alongside a few system registers:
| Area | Content | Access |
|---|---|---|
| User memory (blocks 0 to 63) | 256 bytes in 32-bit blocks | Free reading; block-by-block writing, individual permanent locking |
| AFI and DSFID registers | Application family and data format | Writable, then permanently lockable |
| System area | 8-byte UID and 32-bit kill code | UID set at the factory; kill code writable then lockable |
Used as a Type 5 NFC tag, the 256 bytes host an NDEF record representing a URL of around 240 characters, with the first block hosting the Capability Container. Writing a block takes around 5 ms.
Features & security
- Permanent block-by-block locking: each 32-bit block can be locked individually and irreversibly with the Lock Block command; the locking status of the whole memory remains readable at any time by the reader.
- Deactivation kill code: a 32-bit code, written and then locked by the issuer, makes it possible to permanently deactivate the chip (the Kill command, executed with the right code, silences it forever): the direct ancestor of the kill mode of the ST25TV.
- AFI and DSFID application sorting: the AFI (application family) and DSFID (data format) registers, writable and then lockable, let readers query only the tags of their application during inventory.
- Inventory optimized for moving tags: the Initiate and Inventory Initiated commands (with their fast variants at 53 kbit/s) inventory in small batches the tags passing in front of the reader, on a conveyor for example, without waiting for the full anticollision tree walk.
- The long-range legacy: compliant with the ISO/IEC 15693 and ISO 18000-3 Mode 1 standards, the LRI2K can be read at a distance by vicinity RFID readers, with an endurance of one million cycles and 40 years of retention, guarantees of its longevity in service.
Still offered in wafer form, the LRI2K comes in two tuning capacitances (21 pF and 97 pF) and lends itself to software-controlled electronic article surveillance (EAS). Its secure sibling, the LRIS2K, added extra protections; its modern heir is the ST25TV02K, which carries over its 256 bytes while adding today's protections.
Compatibility
The LRI2K 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 LRI2K chip supports reading technical information, writing records, erasing and locking. The kill code and the AFI and DSFID registers are managed through the chip's dedicated commands. The list of compatible models is available in the article on compatibility.
LRI2K vs ST25TV02K
| Chip | User memory | Security | Typical use |
|---|---|---|---|
| LRI2K | 256 bytes | Block locking, kill code | The historical generation, existing fleets |
| ST25TV02K | 256 bytes | Encrypted passwords, TruST25, kill and untraceable, EAS | The current heir |
With equal memory, the ST25TV02K takes over the role of the LRI2K while adding modern protections (encrypted passwords, TruST25 signature, reversible untraceable mode, hardware EAS anti-theft) and retention raised to 60 years. The LRI2K remains relevant for systems already deployed; for a new ISO 15693 project, the ST25TV family is the way to go, with the ICODE SLIX covering the same ground on the NXP side.
Frequently asked questions
How much data can be stored on an LRI2K?
The chip offers 256 bytes, entirely dedicated to the user, in 64 blocks of 4 bytes. In NDEF usage, that represents a URL of around 240 characters, enough for an enriched link or a small vCard.
What is the kill code of the LRI2K for?
To permanently deactivate the chip: the issuer writes a 32-bit code and then locks it; the Kill command, presented with this code, then silences the chip forever (at the end of the product's life or for confidentiality). It is the direct ancestor of the kill mode of today's ST25TV.
Is the LRI2K 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 LRI2K be protected against rewriting?
Yes: each block can be locked individually and permanently, including from NFC Tools, and the AFI and DSFID registers can be locked in the same way. There is however no reversible password protection: for that feature, the ST25TV family is the way to go.
