Experienced buyers usually open a quotation request the same way: which chip is in it? That is a fair place to start. In any RFID chip comparison the integrated circuit is the one part of a passive UHF tag with a published datasheet you can hold a supplier to — and a vendor who will not name the IC cannot be held to a performance specification.
It is also only half the answer. In a passive UHF tag — RAIN RFID, EPC Gen2, ISO/IEC 18000-63 — the chip sets the ceiling; the antenna, substrate and housing decide how much of it you reach on your asset. Most chip questions then answer themselves — including the many projects where the choice does not matter.
What the chip decides — and what it does not
Read sensitivity is the headline IC specification: the power at which the chip wakes up and replies. A more sensitive chip returns more range from the same antenna, all else being equal — but “all else” is rarely equal: the antenna and the mounting surface move the result far more than a chip swap does.
| Decided by the chip (IC) | Decided by the antenna, inlay and housing | Decided by the reader and the site |
|---|---|---|
| Read sensitivity (power to wake the chip) | Actual read range on your asset | Transmit power, within regional limits |
| Memory: EPC length, user memory, TID | Behaviour on metal, liquid or the body | Antenna gain, polarisation, placement |
| Security and authentication features | Orientation sensitivity and beam shape | Reader settings: session, Q, dwell time |
| Data rates and protocol extensions | Frequency tuning peak for your region | Tag density in the field |
| Write speed and robustness | Survival: heat, chemicals, impact, washing | Item speed through the read zone |
The practical consequence: a top-tier chip on a poorly tuned antenna riveted to steel will usually read worse than a mid-range chip on a properly designed on-metal tag. Chip sensitivity typically shifts range by a modest fraction; construction and antenna design routinely move it by multiples. If you cannot read the tag on the pallet, the fix is almost never a different IC — see antenna gain and polarisation and tag types and constructions.
One naming trap: the same brand appears on both sides of the link. Impinj makes tag ICs and reader silicon — the R2000 in many fixed readers is a reader chip, not a tag chip, so “Impinj inside” on a reader datasheet says nothing about the tags you buy.
The memory map: EPC, TID, User and passwords
Gen2 gives every tag four memory banks; knowing what belongs in each prevents most encoding mistakes.
| Bank | What it holds | Who writes it | What to watch |
|---|---|---|---|
| Reserved | Access and Kill passwords (32 bits each in the Gen2 standard) | You, at encoding | Kill is permanent; a forgotten access password is unrecoverable |
| EPC | The identity you assign — the number the reader reports | You, at encoding | 96 bits is the common baseline; longer EPCs are often available, sometimes trading against user memory |
| TID | Factory-programmed, locked chip identifier | The chipmaker | Manufacturer and model code; most current parts add a unique serial |
| User | Optional free space for data carried on the tag | You | Size varies enormously by part; many chips have none at all |
EPC is the working identity. GS1’s SGTIN-96 fits the 96-bit baseline, which is why so many tags ship that way; ask for a longer EPC only if your numbering scheme needs it.
TID is the anti-cloning tool. Written at the wafer and permanently locked, it cannot be rewritten — an attacker can copy an EPC onto a blank tag, but that tag still carries its own TID. Binding EPC to TID in your database and checking the pair at read time is a cheap, strong integrity check. Its limit: TID authenticates the chip, not that the chip is still on the genuine item, and it is no substitute for cryptographic authentication where counterfeiting is a real commercial threat.
User memory is the bank buyers most often over-specify. Data on the tag means more air time per read, slower inventories and a second copy of the truth to sync. Unless the tag must be readable where your database is not — remote maintenance records, a self-contained item history — keep the data in the database and let the EPC be the key.
Passwords and locking need deciding before encoding, not after. Which banks are locked, which permalocked, whether an access password is set, whether kill is disabled — write that policy into the purchase order, because reversing it usually means rebuying tags.
The main UHF chip families, at a general level
Three families cover most commodity UHF tags, though other silicon vendors are active. The positioning below is general; exact sensitivity figures, memory sizes and feature sets differ by part number and revision, so confirm them on the chipmaker’s current datasheet before committing.
| Family | Commonly positioned around | Typically chosen for | Verify on the datasheet |
|---|---|---|---|
| Impinj Monza / M-series (e.g. M700-series) | Sensitivity and reliable inventory in dense, fast-moving populations; Impinj also promotes Gen2X | High tag density; item-level retail; range from small inlays | Part suffix, memory configuration, which Gen2v2 or Gen2X features are enabled |
| NXP UCODE (e.g. UCODE 8, UCODE 9) | Sensitivity plus tag-integrity and self-check features; some variants positioned for brand protection or authentication | Broad label and inlay converting; product-authentication projects | Which variant: feature sets differ within a generation; memory and authentication support |
| Alien Higgs (e.g. Higgs-3, Higgs-4, Higgs-9) | A long-established general-purpose line, commonly noted for user-memory options | Tags that genuinely carry data; general asset tags | User-memory size for the exact part, EPC length options, availability |
A family name is not a part number: “UCODE 9” or “M700-series” narrows the field, but memory configuration and feature enablement still vary. Specify the full part, and treat any dBm or bit-count figure in a sales email as provisional until you see it in the manufacturer’s own document.
Gen2v2 and Gen2X in one paragraph
Gen2v2 is a revision of the EPC Gen2 standard that added security features such as tag authentication and untraceable/privacy modes; Gen2X is a set of extensions promoted by Impinj — and, as reported in 2026, licensed to other chipmakers — aimed at faster, more reliable reads in dense and moving-item environments. Both need matching support at the reader end: a Gen2X-capable chip read by an ordinary reader behaves like an ordinary Gen2 tag. If either is offered as a headline feature, ask which commands are implemented and which readers you need. Our RFID glossary defines both, plus TID, RAIN and the other terms used here.
How to specify a chip in an RFQ
A chip specification a supplier can be held to has seven lines:
- Exact part number and variant — the family alone is not enough.
- EPC memory in bits, plus the encoding scheme (SGTIN-96, custom, or plain serial).
- User memory in bits — or an explicit “none required”, which widens your options and lowers cost.
- TID requirement — unique serialised TID, and whether the TID list ships with the goods.
- Lock policy — banks locked or permalocked, access password set or not, kill handling.
- Region tuning — the destination market, so the inlay is tuned for the right band.
- Change notification — written notice before any change of chip, substrate or converter — a silent substitution changes both sensitivity and the memory map.
Then run the only test that settles it: a sample lot from production tooling, mounted on the real asset in the real orientation, read with the reader you will deploy. Our supplier checklist covers the rest of that qualification round.
When the chip does not matter
For a large share of projects — indoor asset registers, IT equipment, tool cribs, file tracking, returnable containers — a 96-bit EPC with no user memory on any current mainstream IC does the job, and the difference between families disappears into the noise of antenna placement. The money is better spent on form factor, mounting, reader and antenna positioning, and a clean encoding process.
The chip earns real scrutiny in four situations: authentication or brand protection; dense populations read at speed; maximum range from a physically small inlay; and anything that must carry data on the tag itself. Otherwise, specify the memory you need, leave the family open, and let your supplier choose from what is reliably available.
How we handle chip selection
Identium Tech Solutions Pvt Ltd is an RFID manufacturer with its factory and office in New Delhi, India — operating since 2010, incorporated in 2018. We build UHF tags and inlays and labels around commonly available UHF ICs and match the chip to the application. We are not the exclusive partner of any chipmaker; what a tag manufacturer usefully offers is honest chip selection plus an antenna and housing designed around your asset.
Tell us the memory you need (EPC length, user memory or none), whether authentication or brand-protection features matter, the surface and environment, and the destination market via our contact page, and we will propose a chip and construction, naming the exact part in the quotation rather than sending a catalogue. Custom tags typically turn around in 5–10 days, and every unit is tested in-house before dispatch.
On certification, the honest position: we are BIS certified, and our UHF readers and antennas are WPC-approved for India’s 865–867 MHz band. We do not hold CE, FCC, RoHS, REACH or ISO 9001 certification and will not imply otherwise. Tell us the destination market and we will confirm, per order, what we can and cannot support.
General technical guidance only. Chip specifications, availability and feature sets change — verify sensitivity figures, memory sizes and features against the chip manufacturer’s current datasheet, and confirm frequency and approval requirements for your destination market with your national regulator.