DS1971 EEPROM iButton
256-bit EEPROM — non-volatile without a battery.
The smallest and cheapest rewritable memory in the family, and the only one that pairs its EEPROM with a separate 64-bit one-time-programmable register. Write your permanent identifier into the OTP register and lock it forever, while the 256-bit EEPROM stays free for data you still need to change — a fixed asset number alongside a rewritable status field, in one battery-free button that keeps its contents for decades.
Rewritable data plus a permanently lockable ID
The 64-bit OTP register is what sets it apart. Every other EEPROM part here gives you memory you can change; only the DS1971 also gives you a small block you can burn once and never alter, sitting in the same device. That is exactly what asset tagging wants — an immutable serial that survives every field update, next to a scratch area the technician can rewrite. If you need more room, step up to the DS1972 (1 Kb) or DS1973 (4 Kb); if you need everything to be permanent, use the DS1982 add-only EPROM.
Key features
- Rewritable 256-bit EEPROM over 1-Wire — non-volatile with no battery.
- Extra 64-bit one-time-programmable register auto-locks after writing — for permanent calibration or ID data.
- Very high endurance: 200,000 write cycles at +25 °C; 40-year data retention at +85 °C (shared DS2430A die).
- Family code 14h; unique 64-bit ROM ID; parasite-powered; 2.8–6.0 V, −40 to +85 °C.
- Original imported dies, canned and assembled at our own line — original-chip reliability at a sharper price; laser-etched custom marking and logos to order.
Specifications
| Chip / compatibility | DS1971 · family code 14h · shares its die with the DS2430A chip form |
|---|---|
| Memory | 256-bit EEPROM organized as a single 256-bit page + separate 64-bit one-time-programmable (OTP) register + 256-bit scratchpad · reads and writes from 2.8 V to 6.0 V |
| Operating temperature | −40 to +85 °C · battery-free, decades of retention |
| Package | Rugged stainless MicroCan, F5 size, Ø16.25 × 5.89 mm · approx. 3 g — built to survive harsh application environments |
| Protocol | 1-Wire® |
| Options | Laser-etched custom marking / logo on the can |
Product dimensions
Inside the stainless can
A 0.25 mm solid stainless shell, a UV-stable polypropylene grommet isolating lid from base, and the die bonded inside. Lid = data contact, base = ground return.
Which memory iButton do you need?
The whole memory range side by side, grouped by storage technology — capacities and family codes per the Analog Devices datasheets.
| Model | Family code | Capacity | Memory technology | Pick it for |
|---|---|---|---|---|
| DS1971 | 14h | 256 bit + 64-bit OTP | EEPROM — battery-free | Asset tag: a locked ID beside rewritable data |
| DS1972 | 2Dh | 1 Kbit (128 B) | EEPROM — battery-free | Per-page write-protect or EPROM-emulation modes |
| DS1973 | 23h | 4 Kbit (512 B) | EEPROM — battery-free | Largest battery-free memory; production travellers |
| DS1982 | 09h | 1 Kbit (128 B) | EPROM — add-only, cannot be erased | Tamper-evident checkpoints and certificates |
| DS1985 | 0Bh | 16 Kbit (2 KB) | EPROM — add-only, cannot be erased | Full append-only service history |
| DS1992 / DS1993 | 08h / 06h | 1 Kbit / 4 Kbit | NV RAM — battery-backed, unlimited writes | Data that changes constantly on the key |
| DS1996 | 0Ch | 64 Kbit (8 KB) | NV RAM — battery-backed, unlimited writes | Portable database — the largest capacity here |
| DS1994 | 04h | 4 Kbit + RTC | NV RAM + clock, timer, counter, alarms | Time- or usage-limited access that expires by itself |
| DS1904L | 24h | No user memory | Real-time clock only | Give a microcontroller an accurate timebase |
| DS1991 | 02h | 1152 bit = 3 × 384 bit | Secure NV RAM — three password zones | Legacy multi-tenant systems (not for new secure designs) |
| DS1961S | 33h | 1 Kbit + 64-bit secret | EEPROM + SHA-1 challenge–response | The anti-cloning choice — proves it knows a secret |
Ordering information
| MOQ | 100 pcs |
|---|---|
| Lead time | 3–7 days for stock items, 10–15 days for OEM |
| Packing | Bulk ESD bags (100–200 pcs/bag, 2 bags/carton); blister or header cards for retail on request |
| Samples | Free samples for volume buyers — courier at cost |
| Payment | T/T bank transfer; other terms negotiable for repeat orders |
| Shipping | DHL / FedEx / UPS air express; sea or rail freight for pallet volumes |
| Customization | ROM ranges · housing colours · laser logo · private label |
Typical applications
Related products
DS1991 MultiKey iButton
Three password-protected 384-bit subkeys in one button.
DS1992 / DS1993 Memory iButton
1 Kb and 4 Kb NV RAM tokens for carrying data on the key.
DS1996 64 Kb Memory iButton
The large-memory token — 64 Kb of rewritable NV RAM.
DS1961S SHA-1 Authentication iButton
1 Kb EEPROM with on-chip SHA-1 challenge–response.