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Microchip Technology 25AA02UIDT-I/SN
- Part No.:
- 25AA02UIDT-I/SN
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
25AA02UIDT-I/SN.pdf
- Description:
- IC EEPROM 2KBIT SPI 10MHZ 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,365
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Product details
Overview
25AA02UIDT-I/SN from Microchip Technology Inc. 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/SN datasheet, 25AA02UIDT-I/SN pinout, 25AA02UIDT-I/SN application, or 25AA02UIDT-I/SN equivalent, this page delivers verified electrical specs, SPI timing constraints, UID memory mapping, hardware write protection behavior, and real-world use cases in IoT node identity management, firmware version tracking, and calibration data binding.
Technical Context
The 25AA02UIDT-I/SN implements a standard SPI Mode 0,0 interface with separate SI and SO lines, CS-controlled selection, and HOLD-enabled transaction suspension. Its internal architecture includes an 8-bit instruction register, page latches, and nonvolatile STATUS register with WIP/WEL/BP0/BP1 bits.
Factory programming fixes BP1=0 and BP0=1 to protect the upper 1/4 array (0xC0–0xFF), securing the preprogrammed UID and manufacturer/device codes (0x29 at 0xFA, 0x51 at 0xFB). Write enable latch reset occurs on power-up, WRDI, WRSR, WRITE completion, or WP low assertion.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 256 × 8-bit (2 Kbit) EEPROM array; 192 bytes user-accessible after UID block protection |
| Unique ID | 32-bit factory-programmed serial number at 0xFC–0xFF; globally unique across all Microchip UID-family devices |
| Interface | SPI-compatible serial bus (Mode 0,0); requires CS, SCK, SI, SO, WP, HOLD, VCC, VSS |
| Write Speed | Max 5 ms internal byte/page write cycle; no external delay required after CS high assertion |
| Voltage Range | 1.8V to 5.5V supply; full functionality maintained across entire range including 10 MHz max clock at ≥4.5V |
| Endurance & Retention | 1,000,000 erase/write cycles; >200 years data retention at +85°C |
| ESD Protection | ±4 kV HBM on all pins; enables robust operation in handheld and industrial environments |
Pinout & Package
25AA02UIDT-I/SN is packaged in 8-lead SOIC (SN) with 1.27 mm pitch, RoHS-compliant matte tin finish, and laser-marked pin 1 identifier. Pin functions are electrically identical to SOT-23 variant but mapped to 8-pin layout.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS (Pin 1) | Chip Select Input | Active-low enable; deselect forces SO to high-impedance, enabling multi-device SPI bus sharing |
| SO (Pin 2) | Serial Data Output | Tri-state output updated after SCK falling edge; high-Z when CS high or HOLD low |
| WP (Pin 3) | Hardware Write-Protect | Low = blocks all writes to array and STATUS register; does not interrupt ongoing write cycle |
| VSS (Pin 4) | Ground Reference | Return path for all I/O and core logic; must be connected before VCC during power sequencing |
| SI (Pin 5) | Serial Data Input | Latches instruction/address/data on SCK rising edge; sampled first after CS low assertion |
| SCK (Pin 6) | Serial Clock Input | Synchronizes all SPI transfers; max 10 MHz at VCC ≥ 4.5V; rise/fall time ≤ 100 ns |
| HOLD (Pin 7) | Transaction Pause Control | Low while SCK low suspends communication; resumes from same state without reinitialization |
| VCC (Pin 8) | Supply Voltage | 1.8–5.5V input; powers internal HV generator for EEPROM programming; decoupling capacitor required |
Key Features
| Feature | Design Value |
|---|---|
| Preprogrammed UID Block | 32-bit serial number at fixed 0xFC–0xFF addresses, protected by factory-set BP bits-enables zero-touch device identity provisioning |
| Flexible Block Protection | BP0/BP1 bits allow software-selectable write protection of none, upper 1/4 (0xC0–0xFF), upper 1/2 (0x80–0xFF), or full array (0x00–0xFF) |
| Power-On Safety | Write enable latch resets at power-up; WP pin low also resets latch-prevents accidental writes during brown-out or reset conditions |
| Hold Functionality | HOLD pin pauses active SPI transfer without losing internal state-allows host MCU to service higher-priority interrupts mid-sequence |
| Extended UID Support | Manufacturer code (0x29) at 0xFA and device ID (0x51) at 0xFB enable deterministic 48-bit+ serial number construction via contiguous read extension |
Applications
| IoT Device Identity Management | Firmware Version & Calibration Binding |
|---|---|
Use Scenario: Assigning cryptographically verifiable identity to edge sensors in battery-powered LPWAN networks. IC Role / Device Role / Timing Role: Stores immutable 32-bit UID used as seed for ECC key generation and device certificate signing. Use Value: Eliminates need for external secure element; UID uniqueness ensures no collision across global deployments of identical sensor models. | Use Scenario: Tying firmware revision hash and factory calibration coefficients to specific hardware units during production test. IC Role / Device Role / Timing Role: Nonvolatile storage for 16-byte SHA-256 firmware digest and 12-byte linear calibration offsets, written once per unit. Use Value: Enables field firmware rollback detection and traceable calibration correction without modifying main microcontroller flash. |
| Secure Boot Configuration Lock | Industrial Equipment Serial Numbering |
Use Scenario: Storing boot policy flags (e.g., "allow unsigned update", "require signature") that must survive MCU reset and power loss. IC Role / Device Role / Timing Role: SPI-accessible configuration register with hardware WP pin enabling permanent lockdown after final validation. Use Value: Prevents malicious tampering with boot settings; WP pin physically asserted during end-of-line test ensures irreversible lock. | Use Scenario: Generating globally unique serial numbers for PLC modules where each unit requires traceability to manufacturing batch and test station. IC Role / Device Role / Timing Role: Host MCU reads UID, appends date-code and station ID, then writes full serial string to unprotected lower memory pages. Use Value: Leverages factory-guaranteed UID uniqueness while allowing flexible serialization format-reduces BOM count vs. laser-marked labels. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM with unique ID 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; slightly higher standby current (2 µA vs. 1 µA at 2.5V) | Compatible pinout and SPI protocol; lacks extended UID support via contiguous read beyond 0xFF | Acceptable for cost-sensitive designs where UID length is strictly 32-bit and ultra-low standby current is not required. |
| AT25DF021A-SSH-T | 2 Mbit SPI DataFlash with no factory UID; requires host-managed UID generation and storage in user area | Higher density and faster page program (3 ms), but adds software complexity for UID lifecycle management | Preferred when >2 Kbit user memory is needed and host MCU can handle UID provisioning, persistence, and collision avoidance. |
Compared with 25AA02UIDT-I/SN, 25LC02UID-I/SN offers identical functionality at marginally higher power, while AT25DF021A-SSH-T trades built-in UID assurance for scalable memory-making 25AA02UIDT-I/SN optimal for compact, secure identity-critical applications.
Availability
25AA02UIDT-I/SN is available at Aetrix Electronics and suitable for IoT device identity management, firmware version binding, and industrial equipment serial numbering requiring stable component supply and guaranteed UID uniqueness across production volumes.
Supply support for 25AA02UIDT-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 microcontrollers, analog components, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.
The 25AA02UID product line delivers factory-programmed unique identifiers for secure device authentication and traceability in resource-constrained embedded systems, targeting IoT endpoints, industrial controllers, and consumer electronics requiring tamper-resistant identity.
FAQ
What is the exact memory organization and UID location for 25AA02UIDT-I/SN?
The 25AA02UIDT-I/SN contains 256 bytes (2 Kbit) organized as 256 × 8-bit. The factory-programmed 32-bit serial number resides at memory addresses 0xFC through 0xFF. Manufacturer code 0x29 is at 0xFA and device identifier 0x51 is at 0xFB. The upper 1/4 block (0xC0–0xFF) is write-protected by default via BP1=0 and BP0=1 in the STATUS register, ensuring UID integrity unless explicitly modified.
How does the HOLD pin function during an active SPI transaction on 25AA02UIDT-I/SN?
The HOLD pin on 25AA02UIDT-I/SN suspends SPI communication without resetting internal state when pulled low while SCK is low. During HOLD, SI, SCK, and SO enter high-impedance, and input transitions are ignored except for CS. Resuming requires bringing HOLD high while SCK remains low. This allows the host MCU to service urgent interrupts and resume exactly where the transaction paused-critical for real-time system responsiveness.
Can the 32-bit UID in 25AA02UIDT-I/SN be extended to longer lengths, and how is it implemented?
Yes, the 32-bit UID in 25AA02UIDT-I/SN can be extended to 48-bit, 64-bit, 128-bit, or 256-bit lengths by reading contiguous memory starting from lower addresses (e.g., 0xFA–0xFF for 48-bit). Table 3-1 in the datasheet defines address ranges: 0xF8–0xFF yields 64-bit, 0xF0–0xFF gives 128-bit. The 32-bit base UID guarantees uniqueness, so any padding preserves global uniqueness-enabling flexible serialization schemes without additional hardware.
What are the hardware write protection mechanisms available on 25AA02UIDT-I/SN?
25AA02UIDT-I/SN provides dual-layer hardware write protection: (1) WP pin (Pin 3) disables all writes when low, regardless of STATUS register state; (2) BP0/BP1 bits in the STATUS register enable software-selectable block protection of none, upper 1/4 (0xC0–0xFF), upper 1/2 (0x80–0xFF), or full array. Factory defaults set BP1=0/BP0=1 to protect the UID block. Both mechanisms operate independently and concurrently.
What is the maximum SPI clock frequency supported by 25AA02UIDT-I/SN across its voltage range?
25AA02UIDT-I/SN supports up to 10 MHz SPI clock frequency when VCC is 4.5V to 5.5V, 5 MHz at 2.5V to 4.5V, and 3 MHz at 1.8V to 2.5V. These values are specified in Table 1-2 AC Characteristics and reflect guaranteed timing margins under industrial temperature range (−40°C to +85°C). All timing parameters-including setup/hold times and output valid delays-are voltage-graded to ensure reliable operation across the full 1.8–5.5V supply range.
25AA02UIDT-I/SN Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- 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:
- 8-SOIC
25AA02UIDT-I/SN FAQ
1.How can I place an order for 25AA02UIDT-I/SN through Aetrix?
Please submit a Request for Quotation (RFQ) for 25AA02UIDT-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 25AA02UIDT-I/SN reliable?
The price and inventory of 25AA02UIDT-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 25AA02UIDT-I/SN is usually 5 days.
3.What payment methods are accepted for 25AA02UIDT-I/SN?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 25AA02UIDT-I/SN transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 25AA02UIDT-I/SN?
25AA02UIDT-I/SN orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 25AA02UIDT-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 25AA02UIDT-I/SN?
For technical support, including 25AA02UIDT-I/SN datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 25AA02UIDT-I/SN requirements.
6.How does Aetrix verify that 25AA02UIDT-I/SN is sourced from the original manufacturer or authorized distributors?
All 25AA02UIDT-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 25AA02UIDT-I/SN meets industry standards.
7.What is the process for return or replacement of 25AA02UIDT-I/SN?
All 25AA02UIDT-I/SN units undergo pre-shipment inspection (PSI). If there is an issue with 25AA02UIDT-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 25AA02UIDT-I/SN part is unused and in its original packaging.
Return procedure for 25AA02UIDT-I/SN:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
25AA02UIDT-I/SN Tags
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M24C02-WMN6TP
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AT24C02C-XHM-T
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AT21CS01-STUM10-T
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