ST25TV02KC Explained: ST's NFC Type 5 Chip for Authentication and Tiny Tags

Our chip-guides series has mostly covered the workhorses of B2B tagging: NXP's NTAG family on the NFC side, and the RAIN RFID flagships from NXP and Impinj on the UHF side. This one covers a chip that plays a different game: STMicroelectronics' ST25TV02KC, an ISO/IEC 15693 tag IC positioned for product identification and protection — origin verification, anti-cloning, and tamper evidence — in a package small enough for jewelry, pharma vials, and bottle caps. If your project is less "link to my website" and more "prove this product is genuine," this is the silicon that segment is built on. Here is what is verified in ST's datasheet, and what it means for tag buyers.

What the ST25TV02KC Is

The ST25TV02KC is a 13.56 MHz tag IC compliant with ISO/IEC 15693 and certified by the NFC Forum as a Type 5 tag, currently in volume production at ST. It can be operated by an NFC smartphone or a 13.56 MHz long-range RFID reader, letting it straddle consumer authentication and industrial logistics. It ships in a 5-pin ECOPACK2 (RoHS-compliant) package — UFDFPN5, 1.7 × 1.4 mm — as well as bumped and sawn wafer for customers (like us) who build custom inlays. It has a smaller-memory sibling, the ST25TV512C, with the same feature set minus the tamper interface.

The verified numbers, straight from the datasheet:

The Security Feature Set — Why This Chip Exists

Three datasheet-level features separate the ST25TV02KC from a commodity Type 2 NFC chip:

• TruST25 digital signature. Each chip holds a digital signature generated by ST's TruST25 process, letting a reader verify the chip is genuine ST silicon — the foundation of clone detection. When counterfeiters copy a genuine tag's data onto cheap lookalike chips, signature verification fails.
• Tamper detection with event memory (ST25TV02KC-T only). The -T variant exposes a tamper interface that records open and resealed events — the same digital-seal concept we covered in our tamper-evident NFC guide, implemented in the chip rather than the antenna. The -A variant omits it; check which one your design needs before ordering.
• A real memory-protection system. User memory can be partitioned into one area protected by a 64-bit password, or two areas each protected by a 32-bit password; the system configuration block has its own 32-bit password. Passwords support cover coding, recovery, and a failed-attempt counter, and blocks can be permanently or temporarily write-locked. Compared with the 32-bit password of an NTAG21x chip, this is a materially harder tag to tamper with.

Augmented NDEF: Dynamic Content Without Rewriting the Tag

The chip's most unusual feature is what ST calls Augmented NDEF — a "contextual automatic NDEF message service." In plain terms, the tag can return dynamic content to the reader without anyone explicitly rewriting its EEPROM. ST's use case: the same physical tag serves different content depending on context — before and after a tamper event, for instance, or across product lifecycle stages — without a field-update campaign across millions of tags, which matters for brand-protection programs that cannot recall products to rewrite labels. Which contexts trigger which messages is configured in the chip; if your program needs this, it is worth a dedicated engineering conversation with your tag supplier rather than a datasheet-only decision.

Privacy Modes the Datasheet Gets Right

Consumer-facing authentication tags increasingly get privacy scrutiny, and the ST25TV02KC addresses it at the silicon level: a configurable kill mode for permanent deactivation, Silent and Discreet modes for reversible deactivation, and an untraceable mode with configurable responsiveness. For luxury and pharma programs in privacy-regulated markets, having these modes in the chip simplifies the compliance story.

Why Two Tuning Capacitances Matter

The 23 pF / 99.7 pF tuning-capacitance choice is easy to skim past, but it decides what tags you can build. The higher the tuning capacitance, the smaller the antenna loop needed to resonate at 13.56 MHz — so the 99.7 pF option is what makes very small form factors practical: a tag on a jewelry piece, a label inside a pharma vial cap, a band around a premium bottle neck. The 23 pF option suits conventional label antennas where read range matters more than footprint. When you RFQ "small ST25TV02KC tags," the antenna designer is really choosing between these two variants — specify target size and read distance, and let the antenna engineering follow.

ST25TV02KC vs NTAG213: Different Tools for Different Jobs

Both run at 13.56 MHz and both are readable by NFC phones — but they are not interchangeable:

The NTAG213 remains the sensible default for ordinary NFC labeling (our NTAG comparison guide covers that family in depth). The ST25TV02KC earns its premium when the tag's job is to prove something — origin, integrity, or authenticity. Memory sizing follows the usual logic: 320 bytes is plenty for a UID plus a URL and signature data — if you are counting bytes, revisit our NFC memory guide first.

An RFQ Checklist for ST25TV02KC Tags

• Variant: -T if you need the tamper interface, -A if you do not — and confirm the tuning capacitance (23 pF or 99.7 pF) matches the antenna design, or ask us to design around your target size.
• Certification: the chip is NFC Forum Type 5 certified; typical programs rely on chip-level certification — confirm what your brand team requires.
• Memory map: decide single-area (64-bit password) vs dual-area (two 32-bit) protection before encoding, and which blocks get permanently locked at the factory.
• Reader ecosystem: NFC phones work out of the box; long-range 15693 readers are needed for industrial read zones — verify both if your program spans retail and warehouse.
• Encoding: confirm your encoder supports ISO 15693, and ask about factory pre-encoding of signatures, NDEF, and memory locks — the features are only as good as the initialization that sets them.

ST has kept this family in volume production and it is widely available through distribution — a genuine alternative if your program is built on a single NTAG supply line and you want a second source on a different protocol family. For the broader picture on sourcing risk, see our NFC chip supply guide.

What We Do With This Chip

As an OEM/ODM tag factory we build custom inlays and finished labels on the ST25TV02KC — small-form-factor constructions enabled by the 99.7 pF variant, specialty constructions for brand-protection programs, and factory initialization of memory partitions, locks, and NDEF as part of our OEM/ODM service. If you are designing an authentication program around this chip, send the target tag size, read scenario (phone tap, gate, or handheld), and annual volume — we will tell you what the antenna can realistically do at that size.

FAQ

Can a smartphone read an ST25TV02KC tag?

Yes. It is an NFC Forum Type 5 (ISO/IEC 15693) tag, readable by modern NFC phones — Apple added ISO 15693 support in iOS 13, and Android has supported it longer. Industrial workflows can also use 13.56 MHz long-range readers.

Can my NTAG encoder write ST25TV02KC tags?

No. NTAG chips are Type 2 and use a different command set. You need ISO 15693-capable encoding hardware and software — standard for industrial HF encoders, absent from consumer NTAG tools.

What's the difference between ST25TV02KC-T and -A?

The tamper detection interface exists only on the -T variant, which memorizes open and resealed events. The -A variant omits it. Both share the same memory and security features — and the smaller-memory sibling ST25TV512C never has the tamper interface.