24AA256UID-I/SN - 256Kb I2C EEPROM w/ EUI-48/EUI-64 | Microchip
Référence : 24AA256UID-I/SN ✓ Actif| Qté | Prix unitaire | Total |
|---|---|---|
| 1 | $1.85 | $1,85 |
| 10 | $1.66 | $16,60 |
| 100 | $1.48 | $148,00 |
| 500 | $1.32 | $660,00 |
| 1 000 | $1.18 | $1 180,00 |
24AA256UID-I/SN Présentation
An EEPROM (Electrically Erasable Programmable Read-Only Memory) is a non-volatile memory that retains data without power and supports byte-level in-system rewrites, typically used for configuration, calibration constants, and identity records. The 24AA256UID belongs to the broader hierarchy: serial EEPROM -> non-volatile memory -> memory IC -> semiconductor. Compared with Flash, EEPROM offers finer write granularity (byte vs page/sector) at lower write-cycle endurance cost; compared with EPROM, it is in-system programmable without UV erasure.
Key features include 256 Kbit density organized as 32K x 8, 64-byte page write buffer, hardware write-protect pin, sequential read capability, low standby current typically 1 uA, and automotive AEC-Q100 qualification. The factory-programmed EUI-48 / EUI-64 node identity and 32-bit Unique ID let designers drop in IEEE 802 MAC addresses and OEM serial numbers without provisioning at the programming station - a major BOM and process simplification for networked sensors.
The 24AA256UID-I/SN uses a standard two-wire I2C interface with three address pins (A0/A1/A2) supporting up to eight devices on one bus. Internally it provides 32K bytes of user EEPROM plus the locked upper 1/8th of the array holding the 32-bit serial number and EUI blocks; writes to that region are permanently write-protected at the factory.
Typical applications include IoT and industrial sensor node identity, Bluetooth/Wi-Fi MAC address provisioning, asset tracking tags, metering and instrumentation that must carry a globally unique serial number, and automotive sub-systems where AEC-Q100 is required. It is also used as a low-cost parameter/calibration store behind small microcontrollers lacking internal NVM.
Design considerations: the unique ID / EUI region is locked at the factory, so for variants requiring customer-programmed IDs use the standard 24AA256 (no UID suffix) instead. Operating voltage from 1.7V to 5.5V lets the part ride on 1.8V, 2.5V, 3.3V, or 5V rails without level shifters.
This page synthesizes Microchip datasheet specifications, distributor pricing tiers, drop-in pin-compatible alternatives, and practical design notes - distinct value beyond the bare datasheet.
Alternatives de remplacement direct pour 24AA256UID-I/SN — même boîtier, compatible broche à broche. Les références à boîtier différent nécessitant une retouche du PCB sont exclues.
Variantes de cette série
Modèles de la même série directement compatibles avec 24AA256UID-I/SN (même facteur de forme et même empreinte) — différant par Package, Memory Size, Memory Type, Endurance, Memory Organization.
Outil de comparaison rapide — sélectionnez des références alternatives pour une comparaison côte à côte :
24AA256UIDT-I/SN
✅ Remplacement direct✓ En stock
$0.94 / unité
Voir la fiche technique →24AA256UID-I/P
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
24AA256-E/SN
✅ Remplacement direct✓ En stock
$0.59 / unité
Voir la fiche technique →24AA256-I/SN
✅ Remplacement direct✓ En stock
$0.39 / unité
Voir la fiche technique →24AA256T-I/SN
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
24AA02E48-I/OT
✅ Remplacement direct✓ En stock
$0.38 / unité
Voir la fiche technique →24AA256UID-I/SN Spécifications
| Type de mémoire | EEPROM (Electrically Erasable PROM) |
| Taille de mémoire | 256 Kbit |
| Memory Organization | 32K x 8 |
| Memory Interface | I2C (2-wire serial) |
| Operating Voltage Range | 1.7 V to 5.5 V |
| Fréquence d'horloge maximale | 400 kHz |
| Access Time | 900 ns |
| Page Write Buffer Size | 64 bytes |
| Pre-programmed Identity | EUI-48 and EUI-64 IEEE MAC address; 32-bit unique serial number |
| Plage de température de fonctionnement | -40 C to +85 C (Industrial, 'I') |
| Boîtier | 8-pin SOIC (SN) |
| Type de montage | Surface Mount |
| Automotive Qualification | AEC-Q100 |
| Statut RoHS | Compliant |
Configuration des broches de 24AA256UID-I/SN
| Broche 1 | A0 — I2C slave address bit 0 (hardware strap) |
| Broche 2 | A1 — I2C slave address bit 1 (hardware strap) |
| Broche 3 | A2 — I2C slave address bit 2 (hardware strap) |
| Broche 4 | GND — Ground |
| Broche 5 | SDA — I2C serial data (open-drain, requires pull-up) |
| Broche 6 | SCL — I2C serial clock |
| Broche 7 | WP — Write-protect (active high; protects upper 4 KB EUI block when asserted) |
| Broche 8 | VCC — Supply voltage, 1.7 V to 5.5 V |
Applications typiques
24AA256UID-I/SN convient pour 6 applications: IoT Sensor Node Identity (MAC Address Provisioning), Industrial Asset Tracking and Metering, Bluetooth/Wi-Fi Module Identity Storage, Automotive Sub-system Configuration Memory, Medical and Instrumentation Calibration Storage, Consumer Electronics Identity and Settings Memory.
IoT Sensor Node Identity (MAC Address Provisioning)
The 24AA256UID-I/SN is the standard Microchip choice for embedding a globally unique IEEE MAC address in IoT sensor nodes. Its factory-pre-programmed EUI-48 (6-byte) and EUI-64 (8-byte) records let designers skip the in-system MAC provisioning step entirely - the MCU simply reads bytes 0xFA9F-0xFAA5 for the EUI-48 at boot and hands them to the BLE/Wi-Fi stack. With 32 KB of additional user EEPROM, the same chip also stores calibration constants, sensor trim, and per-node security keys. Operating from 1.7 V to 5.5 V at 1 uA standby suits coin-cell sensors that sleep 99% of the time. The 400 kHz I2C clock lets even an 8 MHz Cortex-M0+ read the EUI in under 1 ms, keeping wake-time energy minimal.
Recommandé
Industrial Asset Tracking and Metering
Industrial asset-tracking tags, smart meters, and field-deployed sensors benefit from the 24AA256UID-I/SN's combination of 256 Kbit user storage and a 32-bit factory Unique ID. The unique serial number enables per-device traceability without per-device programming at the factory, while the 32 KB user area holds cumulative meter readings, log records, and configuration. AEC-Q100 qualification permits deployment in non-safety automotive sub-systems (cabin nodes, body controllers) and harsh industrial environments (-40 C to +85 C). I2C bus sharing with sensors means a single host can poll multiple 24AA256UID tags (8 per bus via A0/A1/A2) for inventory scans.
Recommandé
Bluetooth/Wi-Fi Module Identity Storage
Many BLE and Wi-Fi modules lack unique MAC addresses at module-level, requiring the host MCU to load one at every boot. The 24AA256UID-I/SN solves this elegantly by storing the factory-assigned EUI-48 in non-volatile memory that the host reads via a standard I2C transaction. With 900 ns access time at 400 kHz, the MAC address retrieval adds negligible latency to the radio bring-up sequence. The 32 KB of additional storage often hosts radio calibration tables and customer-specific firmware version metadata. Designers appreciate the 1.7-5.5 V range because it matches both 1.8 V BLE module rails and 3.3 V Wi-Fi module rails with no level shifter.
Recommandé
Automotive Sub-system Configuration Memory
AEC-Q100-qualified and rated -40 C to +85 C, the 24AA256UID-I/SN serves as configuration and identity memory for non-safety automotive systems: infotainment modules, climate-control heads, door modules, and seat controllers. The pre-programmed EUI-48 supports V2X and CAN-based node identification schemes, while the 32 KB user area stores vehicle trim options, dealer-programmed settings, and fault-history logs. Page write of 64 bytes accommodates typical configuration blobs in a single I2C transaction, and the hardware WP pin lets firmware freeze the EUI region permanently after assembly. Eight devices per bus (A0/A1/A2 addressing) simplify multi-EEPROM architectures in body controllers.
Recommandé
Medical and Instrumentation Calibration Storage
Patient-monitoring devices, laboratory instruments, and diagnostic equipment often need per-unit calibration tables plus a globally unique device identifier for regulatory traceability. The 24AA256UID-I/SN provides both: the EUI-64 record serves as the unique device identifier (UDI) required by FDA and EU MDR, and 32 KB stores 16-point calibration curves, serial numbers, and manufacturing date codes. The 1.7-5.5 V range matches lithium-battery-powered portable monitors as well as mains-powered benchtop analyzers. The 64-byte page write lets the host update calibration in a single I2C transaction, and 100 nA typical standby (from datasheet) extends battery life on ambulatory devices.
Recommandé
Consumer Electronics Identity and Settings Memory
Smart-home hubs, gaming peripherals, connected appliances, and wearable accessories rely on the 24AA256UID-I/SN to store per-device MAC addresses and user preferences across power cycles. The EUI-48 block eliminates the BOM cost of programming stations for high-volume consumer products, and the 32 KB user area holds device settings, Wi-Fi credentials, and usage history. I2C's two-pin interface is friendly to space-constrained wearables, and the 1 uA standby current preserves coin-cell battery life over multi-year deployments. The 8-pin SOIC footprint (3.9 mm body) fits easily inside earbuds, fitness bands, and remote-control enclosures.
Recommandé
Récapitulatif des produits recommandés
Données de référence d'ingénierie pour 24AA256UID-I/SN — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | 24AA256UIDT-I/SN | 24AA256-I/SN | 24AA02E48-I/OT |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 8-SOIC (SN) | 8-SOIC (SN) - same | 8-SOIC (SN) - same | SOT-23-6 (smaller) |
| Memory Size | 256 Kbit (32 KB user) | 256 Kbit | 256 Kbit | 2 Kbit |
| Pre-programmed EUI-48/EUI-64 | Yes (factory) | Yes (factory) | No (blank) | Yes (EUI-48 only) |
| Operating Voltage | 1.7 V to 5.5 V | 1.7 V to 5.5 V | 1.7 V to 5.5 V | 1.7 V to 5.5 V |
| Max I2C Clock | 400 kHz | 400 kHz | 400 kHz | 400 kHz |
| Automotive Grade (AEC-Q100) | Yes | Yes | No | No |
| Operating Temperature | -40 C to +85 C (I grade) | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C |
| Indicative 1000-pc Price | $1.18 | ~$1.18 | ~$1.05 | ~$0.65 |
Principaux différenciateurs
- Factory-pre-programmed EUI-48 and EUI-64 eliminate per-device programming cost (vs 24AA256-I/SN)
- Automotive AEC-Q100 qualification with same SOIC-8 footprint (vs 24AA02E48-I/OT)
- 32 KB user area in addition to 4 KB factory-locked EUI block (vs 24AA256T-I/SN)
Notes de conception
Estimated: at VCC = 3.3 V and active read at 400 kHz, the 24AA256UID-I/SN draws roughly 1 mA average per Microchip datasheet DS20005215D. Standby drops to 1 uA typical when SDA/SCL are held high and the part is deselected. Use 4.7 kohm pull-ups on SDA and SCL (10 kohm at 1.8 V if bus capacitance is below 50 pF). Add a 100 nF decoupling capacitor within 3 mm of the VCC pin and a 1 uF bulk cap on the rail if VCC comes from a switching converter.
Keep the SDA/SCL traces short and parallel; route them over a continuous ground plane to minimize crosstalk. The 8-pin SOIC has a thermal pad-less footprint, so no central via stitch is required. Place the WP pin either to GND (full array writable) or to VCC (protect upper 4 KB EUI block) directly, or drive it from a GPIO if your firmware needs to toggle write-protection dynamically. A0/A1/A2 must be tied to either GND or VCC - never left floating - to guarantee a deterministic I2C address.
Do not attempt to write the upper 4 KB (addresses 0xF000-0xFFFF) - the EUI region is permanently write-protected at the factory, and write attempts will silently no-op or return NACK. If your design needs to write the device ID yourself, use the standard 24AA256-I/SN instead. Also note that VCC must be within 1.7-5.5 V during I2C transactions; brown-outs below 1.7 V can corrupt in-progress writes despite the write-protect. Add power-rail monitoring if your design operates from a battery that may dip below threshold.
Informations de conformité
AEC-Q100 qualified per DigiKey/Mouser listing (2026-10-06). RoHS and REACH compliance confirmed by Microchip product page. Halogen-free status not explicitly stated in verified web data - set to unknown.
