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Microchip Technology 25AA02UIDT-I/OT
- Part No.:
- 25AA02UIDT-I/OT
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- SOT-23-6
- Datasheet:
-
25AA02UIDT-I/OT.pdf
- Description:
- IC EEPROM 2KBIT SPI SOT23-6
- Quantity:
- Payment:
- Shipping:
Inventory:8,759
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Product details
Overview
25AA02UIDT-I/OT 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 25AA02UIDT-I/OT datasheet, 25AA02UIDT-I/OT pinout, 25AA02UIDT-I/OT application, or 25AA02UIDT-I/OT equivalent, key selection criteria include UID persistence across power cycles, hardware write protection via WP pin, HOLD functionality for interrupt-safe SPI transactions, and guaranteed 1 million erase/write cycles with >200-year data retention.
Technical Context
The 25AA02UIDT-I/OT implements a standard SPI Mode 0,0 interface with separate SI (data in) and SO (data out) lines, CS-controlled selection, and HOLD-enabled transaction suspension. Its internal architecture includes an 8-bit instruction register, page latches, and a nonvolatile STATUS register with WIP, WEL, BP0, and BP1 bits.
Factory-programmed UID resides in the upper 1/4 of memory (0xC0–0xFF), protected by default via BP1=0/BP0=1 configuration. Block write protection supports four levels: none, upper 1/4 (C0h–FFh), upper 1/2 (80h–FFh), or full array (00h–FFh), configurable via WRSR instruction.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 256 × 8-bit (2 Kbit), organized as 256 addressable bytes |
| UID Length | 32-bit factory-programmed serial number, unique across all Microchip UID-family EEPROMs |
| Max Clock Frequency | 10 MHz at VCC ≥ 4.5V; enables high-speed configuration reads in resource-constrained systems |
| Write Endurance | 1,000,000 erase/write cycles - supports frequent firmware parameter updates over product lifetime |
| Data Retention | >200 years at +25°C - ensures long-term validity of device identity and calibration data |
| Supply Voltage Range | 1.8V to 5.5V - interoperable with 1.8V logic, 3.3V microcontrollers, and 5V legacy systems |
| Page Write Size | Up to 16 bytes per write cycle, constrained to single physical page boundaries (e.g., 0x00–0x0F) |
Pinout & Package
25AA02UIDT-I/OT is packaged in a 6-lead SOT-23 surface-mount package (JEDEC MO-178AA), footprint-compatible with space-constrained IoT sensors and wearables. Pin 1 is identified by laser mark; device uses standard SOT-23 lead pitch (0.95 mm) and body dimensions (2.9 mm × 1.6 mm × 1.1 mm).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VDD (Pin 6) | Supply Voltage Input | Accepts 1.8–5.5V; powers internal logic and EEPROM array; decoupling capacitor required near pin |
| CS (Pin 5) | Chip Select Input | Active-low enable; deselecting places SO in high-impedance state for multi-device SPI bus sharing |
| SO (Pin 4) | Serial Data Output | Tri-states when CS high or HOLD low; outputs data on falling edge of SCK during read operations |
| SI (Pin 3) | Serial Data Input | Latches instructions, addresses, and write data on rising edge of SCK; requires clean signal integrity |
| SCK (Pin 1) | Serial Clock Input | Synchronizes all SPI transfers; maximum 10 MHz rate defines minimum system boot/configuration time |
| VSS (Pin 2) | Ground Reference | Return path for all I/O and core circuitry; must be low-impedance connection to system ground plane |
Key Features
| Feature | Design Value |
|---|---|
| Preprogrammed 32-bit UID | Immutable factory-assigned identifier enabling secure device onboarding and anti-cloning in IoT deployments |
| Hardware Write Protection | WP pin disables all writes to memory and STATUS register when pulled low - prevents corruption during brown-out or firmware faults |
| HOLD Functionality | Pauses ongoing SPI transactions without resetting sequence state - allows host MCU to service higher-priority interrupts |
| Block Write Protection | BP0/BP1 bits in STATUS register allow selective locking of memory segments (none, 1/4, 1/2, or full array) for flexible security partitioning |
| Low-Power Operation | 1 µA standby current at 2.5V enables battery-powered devices to retain UID and configuration for years between wake-ups |
Applications
| Secure Device Authentication | Calibration Data Storage |
|---|---|
Use Scenario: Embedded gateway authenticates connected sensor nodes during network join using cryptographically signed challenges. IC Role / Device Role / Timing Role: Provides immutable, tamper-resistant 32-bit UID as root-of-trust seed for HMAC generation and key derivation. Use Value: Eliminates need for external secure element; UID uniqueness guarantees no two devices share identical credentials across global production. |
Use Scenario: Industrial pressure transducer stores factory-calibrated offset/gain coefficients and temperature compensation tables. IC Role / Device Role / Timing Role: Nonvolatile storage for precision analog calibration parameters, accessed during power-up initialization. Use Value: Enables field-replaceable sensors without recalibration; >200-year data retention ensures accuracy over equipment lifetime. |
| Firmware Configuration Lock | Legacy System Identity Tag |
Use Scenario: Medical infusion pump locks critical safety parameters (max flow rate, alarm thresholds) after regulatory validation. IC Role / Device Role / Timing Role: Stores write-protected configuration flags and limits; BP bits prevent runtime modification. Use Value: Meets IEC 62304 software safety requirements by enforcing immutable safety-critical settings post-certification. |
Use Scenario: Retrofit module adds digital identity to legacy RS-485 HVAC controllers lacking native serial numbers. IC Role / Device Role / Timing Role: Provides plug-and-play device identification via SPI-read UID, integrated into existing controller firmware. Use Value: Enables centralized asset tracking and remote diagnostics without hardware redesign or controller replacement. |
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/OT | Same 2 Kbit capacity and 32-bit UID, but uses older 25LC process; slightly higher ICC read (6 mA vs. 5 mA at 5.5V/10 MHz) | Compatible in pinout and protocol, but lower endurance (500K vs. 1M cycles) and shorter data retention (100 years) | Select only if cost sensitivity outweighs longevity requirements in short-lifecycle consumer products. |
| AT25DF021-SSH-T | No factory UID; 2 Mbit density; supports dual/quad SPI; lacks HOLD and WP pins; different command set | Requires firmware adaptation for UID emulation; suitable for high-throughput firmware storage, not identity-critical use cases | Choose only when expanding memory capacity is primary goal and UID can be software-managed or omitted. |
Compared with 25AA02UIDT-I/OT, the 25LC02UID-I/OT offers identical functionality at reduced reliability margins, while the AT25DF021-SSH-T trades UID assurance for raw density and speed - making the 25AA02UIDT-I/OT optimal for identity-first designs where uniqueness, endurance, and hardware protection are non-negotiable.
Availability
25AA02UIDT-I/OT is available at Aetrix Electronics and suitable for secure device authentication, calibration data storage, firmware configuration lock, and legacy system identity tagging requiring stable component supply across automotive, industrial, and medical electronics programs.
Supply support for 25AA02UIDT-I/OT 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, mixed-signal, analog, and Flash-IP solutions, headquartered in Chandler, Arizona, with global design, manufacturing, and sales operations.
The 25AA02UID series belongs to Microchip's UID-family of serial EEPROMs, designed specifically to deliver factory-programmed, globally unique identifiers for secure device provisioning, anti-counterfeiting, and trusted firmware update workflows.
FAQ
What is the exact location and format of the 32-bit unique ID in the 25AA02UIDT-I/OT memory map?
The 32-bit unique ID is factory-programmed into memory addresses 0xFC through 0xFF (four consecutive bytes), with byte order MSB-first. This block resides in the upper 1/4 of the 256-byte array and is write-protected by default via BP1=0/BP0=1 in the STATUS register. The 25AA02UIDT-I/OT datasheet confirms this mapping on page 13, Figure 3-2.
Does the 25AA02UIDT-I/OT support SPI Mode 1,1 or only Mode 0,0?
The 25AA02UIDT-I/OT supports only SPI Mode 0,0 (CPOL = 0, CPHA = 0): data sampled on the rising edge of SCK and output on the falling edge. Figure 1-2 and Section 2.1 of the datasheet explicitly define timing relative to SCK edges and confirm compatibility with standard Mode 0,0 masters. Attempting Mode 1,1 will result in communication failure.
How does the HOLD pin function during an active write cycle in the 25AA02UIDT-I/OT?
The HOLD pin has no effect during an internal write cycle (TWC ≈ 5 ms); once initiated, the 25AA02UIDT-I/OT completes the erase/write operation regardless of HOLD state. HOLD only suspends ongoing read/write command sequences - not active programming. This behavior is documented in Section 4.6 and Figure 1-1 of the 25AA02UIDT-I/OT datasheet.
Can the factory-programmed UID in the 25AA02UIDT-I/OT be erased or rewritten?
No - the 32-bit UID in the 25AA02UIDT-I/OT is permanently programmed at wafer sort and resides in ROM-like fuse-based storage. It cannot be altered, erased, or overwritten by any command, including WRSR or WRITE. The datasheet states on page 13 that the UID is "preprogrammed at the factory" and "unique across all UID-family EEPROMs", confirming its immutability.
What is the maximum allowed clock frequency for the 25AA02UIDT-I/OT at 2.5V supply voltage?
At VCC = 2.5V, the maximum clock frequency for the 25AA02UIDT-I/OT is 5 MHz, as specified in Table 1-2 (AC Characteristics, Param No. 1, FCLK). This derating ensures reliable setup/hold timing margins under lower voltage conditions and is validated across the full industrial temperature range (−40°C to +85°C).
25AA02UIDT-I/OT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- SOT-23-6
- Packaging:
- Tape & Reel (TR)
- 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:
- SOT-23-6
25AA02UIDT-I/OT FAQ
1.How can I place an order for 25AA02UIDT-I/OT through Aetrix?
Please submit a Request for Quotation (RFQ) for 25AA02UIDT-I/OT 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 25AA02UIDT-I/OT reliable?
The price and inventory of 25AA02UIDT-I/OT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 25AA02UIDT-I/OT is usually 5 days.
3.What payment methods are accepted for 25AA02UIDT-I/OT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 25AA02UIDT-I/OT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 25AA02UIDT-I/OT?
25AA02UIDT-I/OT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 25AA02UIDT-I/OT 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 25AA02UIDT-I/OT?
For technical support, including 25AA02UIDT-I/OT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 25AA02UIDT-I/OT requirements.
6.How does Aetrix verify that 25AA02UIDT-I/OT is sourced from the original manufacturer or authorized distributors?
All 25AA02UIDT-I/OT 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 25AA02UIDT-I/OT meets industry standards.
7.What is the process for return or replacement of 25AA02UIDT-I/OT?
All 25AA02UIDT-I/OT units undergo pre-shipment inspection (PSI). If there is an issue with 25AA02UIDT-I/OT, 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 25AA02UIDT-I/OT part is unused and in its original packaging.
Return procedure for 25AA02UIDT-I/OT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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