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Microchip Technology 25AA02UID-I/SN
- Part No.:
- 25AA02UID-I/SN
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
25AA02UID-I/SN.pdf
- Description:
- IC EEPROM 2KBIT SPI 10MHZ 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:302
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Product details
Overview
25AA02UID-I/SN from Microchip Technology is a 2 Kbit SPI serial EEPROM with factory-programmed 32-bit unique ID stored at addresses 0xFC–0xFF, 256 × 8-bit memory organization, 16-byte page write capability, and industrial temperature range (−40°C to +85°C). It operates from 1.8V to 5.5V and supports up to 10 MHz clock frequency for embedded device authentication and secure configuration storage.
For engineers reviewing the 25AA02UID-I/SN datasheet, 25AA02UID-I/SN pinout, 25AA02UID-I/SN application, or 25AA02UID-I/SN equivalent, key selection considerations include UID persistence across power cycles, hardware write-protection via WP pin, HOLD functionality for interrupt-safe SPI bus sharing, and factory-set BP1/BP0 bits protecting the upper 1/4 array containing the serial number.
Technical Context
The 25AA02UID-I/SN implements a standard SPI Mode 0,0 interface with separate SI and SO lines, CS-controlled selection, and HOLD-assisted transaction suspension. Its internal architecture includes an 8-bit instruction register, page latches, and HV generator for EEPROM programming.
It features nonvolatile STATUS register bits (WIP, WEL, BP0, BP1) controlling write enable state and block protection of 0x00–0xFF memory space - with factory default BP1=0/BP0=1 locking 0xC0–0xFF (including UID) against writes. Write cycles complete in ≤5 ms with automatic erase-before-write and no external high-voltage supply required.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 256 × 8-bit (2 Kbit), organized as one contiguous array with UID preprogrammed in upper 1/4 (0xFC–0xFF) |
| Interface | SPI-compatible serial bus (Mode 0,0), requiring CS, SCK, SI, SO, WP, HOLD - no I²C or UART support |
| Max Clock Frequency | 10 MHz at VCC ≥ 4.5V; scales down to 5 MHz (2.5V ≤ VCC < 4.5V) and 3 MHz (1.8V ≤ VCC < 2.5V) |
| Write Endurance | 1,000,000 erase/write cycles per byte, validated at 25°C and 5.5V - critical for firmware update logging |
| Data Retention | >200 years at 25°C - ensures UID and calibration data persist over full product lifecycle |
| Supply Voltage | 1.8V to 5.5V operation - enables direct interfacing with 1.8V, 3.3V, and 5V microcontrollers without level shifters |
| ESD Protection | >4000V HBM on all pins - supports robust deployment in handheld and industrial environments |
Pinout & Package
25AA02UID-I/SN is packaged in 8-lead SOIC (SN) with JEDEC MS-012AC footprint (body size 3.9mm × 4.9mm, lead pitch 1.27mm). Pin 1 marked by laser dot; RoHS-compliant matte tin finish.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS (Pin 1) | Chip Select Input | Active-low enable: drives device into active mode when low; forces SO to high-Z when high - enables multi-device SPI bus sharing |
| SO (Pin 2) | Serial Data Output | Tri-state output shifting data on SCK falling edge - requires external pull-up if shared with other SO lines |
| WP (Pin 3) | Hardware Write-Protect | Low = blocks all writes to memory and STATUS register; overrides WEL state - provides fail-safe UID protection |
| VSS (Pin 4) | Ground Reference | Primary return path for all digital and internal charge-pump currents - must be low-impedance connection |
| SI (Pin 5) | Serial Data Input | Latches instruction/address/data on SCK rising edge - timing-critical input requiring controlled slew rate |
| SCK (Pin 6) | Serial Clock Input | Master-generated clock synchronizing all SPI transactions - rise/fall times ≤100 ns required for 10 MHz operation |
| HOLD (Pin 7) | Transaction Pause Control | Low = suspends ongoing SPI sequence without resetting address pointer - allows MCU to service higher-priority interrupts |
| VCC (Pin 8) | Power Supply | 1.8–5.5V input powering logic, EEPROM array, and internal HV generator - bypass capacitor (0.1 µF) required at pin |
Key Features
| Feature | Design Value |
|---|---|
| Factory-Preprogrammed 32-bit UID | Guaranteed globally unique identifier stored at fixed 0xFC–0xFF addresses - eliminates need for post-manufacture serialization |
| Hardware Block Write Protection | BP1/BP0 bits in STATUS register allow selective lock of none / upper 1/4 / upper 1/2 / entire array - prevents accidental UID overwrite |
| Self-Timed Internal Write Cycle | ≤5 ms byte/page write time with no external timing control needed - simplifies firmware and guarantees completion before next CS assertion |
| Power-On Write Disable | Write enable latch resets at power-up and after every successful write - prevents spurious writes during brown-out or reset conditions |
| HOLD Functionality | Pauses active SPI transfer while preserving internal state - enables deterministic interrupt latency without reinitializing communication |
Applications
| Secure Device Authentication | Firmware Version Tracking |
|---|---|
|
Use Scenario: Embedded system verifies authenticity of peripheral module during boot using cryptographically signed challenge-response with UID as secret seed. IC Role / Device Role / Timing Role: UID source and persistent storage for cryptographic keys - accessed once per boot via SPI read at fixed 0xFC–0xFF addresses. Use Value: Eliminates external secure element; UID's 200+ year retention ensures lifetime identity binding without battery backup. |
Use Scenario: Industrial controller logs firmware revision, build timestamp, and calibration coefficients after each field update. IC Role / Device Role / Timing Role: Nonvolatile configuration store supporting 1M write cycles - writes occur only during OTA updates or manual recalibration. Use Value: Page write mode (16 bytes) minimizes write time per update; BP bits protect UID region while allowing full array use for application data. |
| Calibration Data Storage | IoT Node Identity Management |
|
Use Scenario: Sensor node stores factory-trimmed ADC offset/gain values and temperature compensation coefficients. IC Role / Device Role / Timing Role: Read-mostly memory accessed at startup and during self-test - write occurs only during production calibration. Use Value: 1.8V operation enables direct connection to low-power sensor MCUs; 4 kV ESD rating withstands handling in test fixtures. |
Use Scenario: Smart meter embeds UID-derived EUI-64 address for IEEE 802.15.4 network registration and cloud device onboarding. IC Role / Device Role / Timing Role: Immutable identity anchor - UID extended to 48-bit (0xFA–0xFF) or 64-bit (0xF8–0xFF) per Table 3-1 for standardized addressing. Use Value: Factory-programmed uniqueness removes provisioning step; scalable length supports evolving IoT addressing requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM with UID applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 25LC02UID-I/SN | Same 2 Kbit capacity and 32-bit UID, but uses older 25LC process - lower max clock (4 MHz vs. 10 MHz) and higher ICC (6 mA vs. 5 mA at 5.5V) | Not suitable for high-speed SPI masters or ultra-low-power systems requiring sub-5 mA active current | Select only if legacy design compatibility or cost sensitivity outweighs performance and efficiency gains |
| AT25DF021A-SSH-T | 2 Mbit SPI flash with no factory UID - requires external UID storage or software-based serialization | Supports execute-in-place (XIP) and sector erase, but lacks guaranteed unique ID for device identity | Choose when code storage dominates requirement and UID can be managed separately - not a drop-in UID replacement |
Compared with 25AA02UID-I/SN, 25LC02UID-I/SN trades speed and power efficiency for process maturity, while AT25DF021A-SSH-T offers density and flash flexibility at the cost of integrated UID assurance - making 25AA02UID-I/SN optimal for identity-critical, low-power, SPI-constrained designs.
Availability
25AA02UID-I/SN is available at Aetrix Electronics and suitable for secure device authentication, firmware version tracking, and calibration data storage requiring stable component supply, long-term traceability, and industrial-grade reliability.
Supply support for 25AA02UID-I/SN includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Microchip Technology Inc. is a leading provider of microcontroller, analog, and Flash-IP solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.
The 25AA02UID belongs to Microchip's UID-family of serial EEPROMs, designed specifically for secure device identification, anti-counterfeiting, and trusted configuration storage in industrial, automotive, and IoT endpoints.
FAQ
What is the exact memory organization and UID location for 25AA02UID-I/SN?
The 25AA02UID-I/SN contains 256 bytes (2 Kbit) arranged as a single linear array from 0x00 to 0xFF. Its factory-programmed 32-bit unique ID occupies addresses 0xFC through 0xFF - four consecutive bytes readable via standard SPI READ command. Manufacturer code (0x29) and device identifier (0x51) reside at 0xFA and 0xFB respectively, confirming authentic Microchip UID-family origin.
How does the write protection mechanism work on 25AA02UID-I/SN?
The 25AA02UID-I/SN implements dual-layer write protection: hardware via the WP pin (low = full write disable), and software via BP0/BP1 bits in the STATUS register. At power-up, BP1=0/BP0=1 is factory-set, protecting addresses 0xC0–0xFF - including the UID region. This protection persists until explicitly cleared via WRSR instruction, ensuring UID integrity unless deliberately modified.
Can 25AA02UID-I/SN operate reliably at 1.8V supply voltage?
Yes, 25AA02UID-I/SN is fully specified for 1.8V to 5.5V operation across the industrial temperature range (−40°C to +85°C). At 1.8V, it supports up to 3 MHz clock frequency, draws ≤3 mA during write, and maintains 1 µA standby current - enabling direct integration with 1.8V microcontrollers and ultra-low-power sensor nodes without level-shifting circuitry.
What is the purpose and behavior of the HOLD pin on 25AA02UID-I/SN?
The HOLD pin on 25AA02UID-I/SN pauses ongoing SPI communication without resetting the internal address counter or instruction state. When pulled low (while SCK is low), SI/SO/SCK enter high-impedance and all inputs except CS are ignored - allowing the host MCU to service urgent interrupts. Resuming requires bringing HOLD high while SCK remains low, after which transmission continues seamlessly from the suspended point.
Is the 32-bit UID truly unique across all 25AA02UID-I/SN units?
Yes, the 32-bit serial number programmed into each 25AA02UID-I/SN is globally unique across all Microchip UID-family EEPROMs - guaranteed by Microchip's factory serialization infrastructure. This uniqueness is maintained even when extending the UID to 48-bit, 64-bit, or longer lengths using adjacent memory locations (e.g., 0xFA–0xFF for 48-bit), as the base 32-bit value ensures overall uniqueness.
25AA02UID-I/SN Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- EEPROM
- Technology:
- EEPROM
- Memory Size:
- 2Kbit
- Memory Organization:
- 256 x 8
- Memory Interface:
- SPI
- Clock Frequency:
- 10 MHz
- Write Cycle Time - Word, Page:
- 5ms
- Access Time:
- -
- Voltage - Supply:
- 1.8V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
25AA02UID-I/SN FAQ
1.How can I place an order for 25AA02UID-I/SN through Aetrix?
Please submit a Request for Quotation (RFQ) for 25AA02UID-I/SN on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for 25AA02UID-I/SN reliable?
The price and inventory of 25AA02UID-I/SN are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 25AA02UID-I/SN is usually 5 days.
3.What payment methods are accepted for 25AA02UID-I/SN?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 25AA02UID-I/SN transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 25AA02UID-I/SN?
25AA02UID-I/SN orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 25AA02UID-I/SN order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for 25AA02UID-I/SN?
For technical support, including 25AA02UID-I/SN datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 25AA02UID-I/SN requirements.
6.How does Aetrix verify that 25AA02UID-I/SN is sourced from the original manufacturer or authorized distributors?
All 25AA02UID-I/SN products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that 25AA02UID-I/SN meets industry standards.
7.What is the process for return or replacement of 25AA02UID-I/SN?
All 25AA02UID-I/SN units undergo pre-shipment inspection (PSI). If there is an issue with 25AA02UID-I/SN, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The 25AA02UID-I/SN part is unused and in its original packaging.
Return procedure for 25AA02UID-I/SN:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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