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Microchip Technology 25AA040X-I/ST
- Part No.:
- 25AA040X-I/ST
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
25AA040X-I/ST.pdf
- Description:
- IC EEPROM 4KBIT SPI 1MHZ 8TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:3,460
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Product details
Overview
25AA040X-I/ST from Microchip Technology Inc. is a 4 Kbit (512 × 8) SPI-compatible serial EEPROM with 1.8–5.5 V supply range, 1 MHz max clock frequency, and industrial temperature rating (–40°C to +85°C). It features hardware write protection (WP), hold functionality (HOLD), and 16-byte page write capability. Used for nonvolatile parameter storage in microcontroller-based embedded systems requiring low-power, reliable data retention.
For engineers reviewing the 25AA040X-I/ST datasheet, 25AA040X-I/ST pinout, 25AA040X-I/ST application, or 25AA040X-I/ST equivalent, this page delivers verified electrical specs, validated TSSOP-8 pin mapping, confirmed endurance (1M cycles), real-world use cases, and two technically documented alternative parts - all aligned to Microchip's DS21204E specification.
Technical Context
The 25AA040X-I/ST implements a standard SPI Mode 0,0 or Mode 1,1 interface with separate SI (data in) and SO (data out) lines, controlled by CS, SCK, WP, and HOLD. Its internal architecture includes an 8-bit instruction register, STATUS register with WIP/WEL/BP bits, and page-based write logic limiting writes to 16-byte boundaries within the same memory page.
It supports sequential read with automatic address increment, self-timed internal write cycles (≤5 ms), and dual-layer write protection: hardware via WP pin and software via WREN/WRSR commands. The device powers up with write enable latch reset and SO in high-impedance state, ensuring safe default behavior on system startup.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory size | 4 Kbit (512 × 8-bit array), sufficient for firmware configuration, calibration data, or device ID storage in space-constrained designs |
| Supply voltage | 1.8–5.5 V - enables direct interfacing with 1.8 V, 3.3 V, and 5 V microcontrollers without level-shifting |
| Max clock frequency | 1 MHz at VCC ≥ 4.5 V - defines maximum SPI transaction speed for time-critical parameter updates |
| Write cycle time | ≤5 ms per page - determines minimum latency between successive write operations; no external delay required |
| Endurance | 1 million erase/write cycles - supports long-term logging or frequent field-updatable settings in industrial equipment |
| Data retention | >200 years at +25°C - ensures persistent storage of critical calibration or security keys over product lifetime |
| ESD protection | >4 kV HBM - provides robustness against handling and board-level electrostatic discharge events |
Pinout & Package
25AA040X-I/ST is packaged in an 8-pin Thin Shrink Small Outline Package (TSSOP) with 0.65 mm pitch, 4.4 mm width, and lead-free matte tin finish. Pin numbering follows JEDEC-standard TSSOP orientation (pin 1 marked).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | HOLD | Active-low suspend signal - pauses ongoing SPI transfer without resetting sequence; requires SCK low to activate |
| 2 | VCC | Power supply input - must be stable within 1.8–5.5 V; decoupling capacitor recommended near pin |
| 3 | CS | Chip Select - active-low enable; deselecting forces SO into high-impedance to share SPI bus |
| 4 | SO | Serial Output - data-out line; tri-stated when CS high or HOLD low; MSB-first timing synchronized to SCK falling edge |
| 5 | WP | Write-Protect - hardware lock; low disables all writes to memory and STATUS register regardless of WREN state |
| 6 | VSS | Ground reference - must be connected to system common ground; low-impedance path critical for noise immunity |
| 7 | SI | Serial Input - data-in line; latches instructions, addresses, and data on SCK rising edge |
| 8 | SCK | Serial Clock - synchronous timing source; rising edge clocks data in, falling edge clocks data out |
Key Features
| Feature | Design Value |
|---|---|
| 16-byte page write | Enables efficient burst writes within page boundaries; prevents accidental cross-page overwrite during partial updates |
| Block write protection | Configurable via STATUS register (BP0/BP1) to protect 0%, 25%, 50%, or 100% of memory - supports secure boot loader or factory calibration regions |
| Low-power operation | 500 nA standby current and 3 mA typical write current - extends battery life in portable or energy-harvesting applications |
| HOLD functionality | Allows host MCU to service higher-priority interrupts mid-transfer without losing SPI context or reinitializing communication |
| Power-on write disable | Write enable latch resets at power-up, preventing spurious writes during supply ramp-up or brownout conditions |
Applications
| Industrial Sensor Calibration Storage | Medical Device Configuration Memory |
|---|---|
Use Scenario: Storing factory-calibrated sensor offset/gain coefficients and linearization tables in programmable logic controllers or environmental monitors. IC Role / Device Role / Timing Role: Nonvolatile parameter storage accessed during system initialization; SPI reads occur once per power cycle with no timing constraints. Use Value: Eliminates need for external trimming components; enables field recalibration and firmware updates without hardware modification. | Use Scenario: Holding user-configurable therapy parameters, alarm thresholds, and device serialization data in portable infusion pumps or diagnostic handhelds. IC Role / Device Role / Timing Role: Secure, low-power configuration store accessed via SPI during boot and on-demand; WP pin physically tied low during normal operation. Use Value: Ensures regulatory-compliant data integrity; >200-year retention meets medical device lifecycle requirements. |
| Automotive Body Control Module Settings | Consumer Appliance User Preference Storage |
Use Scenario: Retaining seat/mirror position presets, lighting profiles, and door lock configurations in automotive BCMs operating across –40°C to +85°C. IC Role / Device Role / Timing Role: Industrial-grade EEPROM interfaced to 3.3 V MCU SPI; HOLD used during CAN interrupt servicing to avoid bus contention. Use Value: Meets AEC-Q100 ambient temperature requirement; 1M-cycle endurance supports 10+ years of daily user adjustments. | Use Scenario: Saving cooking modes, timer values, and language preferences in smart ovens or washing machines with touch UIs. IC Role / Device Role / Timing Role: Low-cost, low-pin-count nonvolatile memory sharing SPI bus with display driver and temperature sensor. Use Value: 1.8 V compatibility allows direct connection to modern ultra-low-power MCUs; TSSOP-8 footprint minimizes PCB area. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 25AA040A-I/ST | Enhanced revision with improved ESD performance (>6 kV HBM) and updated AC timing; pinout and functionality identical | Recommended for new designs per Microchip notice; suitable where higher ESD robustness or latest characterization is required | Select 25AA040A-I/ST for production releases; 25AA040X-I/ST remains valid for legacy BOM continuity |
| AT25040B-MAHL-T | 4 Kbit SPI EEPROM from Microchip (acquired Atmel); 2.5–5.5 V supply, 20 MHz max clock, SOIC-8/TSSOP-8 package options | Higher speed and wider VCC range but lacks HOLD pin; requires software-managed transaction suspension | Choose AT25040B-MAHL-T only if clock speed >1 MHz is needed and HOLD functionality is not required |
Compared with 25AA040X-I/ST, the 25AA040A-I/ST offers identical pinout and function with enhanced reliability, while the AT25040B-MAHL-T trades HOLD support for higher throughput - making the original part optimal for interrupt-sensitive, low-power embedded control where deterministic pause capability matters.
Availability
25AA040X-I/ST is available at Aetrix Electronics and suitable for industrial sensor calibration, medical device configuration, and automotive body control module applications requiring stable component supply, long-term data retention, and industrial temperature operation.
Supply support for 25AA040X-I/ST 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 and sales operations.
The 25AA040X-I/ST belongs to Microchip's legacy 25XX040 serial EEPROM family, designed specifically for cost-sensitive, low-power embedded systems needing reliable, SPI-accessible nonvolatile storage with hardware write protection and industrial temperature support.
FAQ
What is the supply voltage range supported by the 25AA040X-I/ST?
The 25AA040X-I/ST supports a supply voltage range of 1.8 V to 5.5 V, enabling interoperability with 1.8 V, 3.3 V, and 5 V microcontrollers without level translation. This wide VCC range is specified for industrial temperature operation (–40°C to +85°C) and is validated per Microchip DS21204E Section 1.0 DC Characteristics.
Does the 25AA040X-I/ST include hardware write protection?
Yes, the 25AA040X-I/ST includes dedicated hardware write protection via the WP (Write-Protect) pin. When WP is held low, all writes to both memory array and STATUS register are disabled - even if the write enable latch is set. This feature is electrically validated and documented in DS21204E Section 2.3 and Table 3-3.
What package type and pin count does the 25AA040X-I/ST use?
The 25AA040X-I/ST uses an 8-pin Thin Shrink Small Outline Package (TSSOP) with 0.65 mm pitch and JEDEC-standard pinout. Package dimensions and mechanical drawings are defined in DS21204E Section 4.1 and Drawing No. C04-086, confirming its compatibility with automated SMT assembly.
How many write/erase cycles is the 25AA040X-I/ST rated for?
The 25AA040X-I/ST is rated for 1 million write/erase cycles, as specified in DS21204E Table 1-2 Note 2 and Section 3.3. This endurance rating is ensured by characterization and supports long-term field updates in applications such as industrial calibration storage and medical device configuration.
Is the 25AA040X-I/ST compatible with standard SPI interfaces?
Yes, the 25AA040X-I/ST is fully compatible with standard SPI interfaces operating in Mode 0,0 or Mode 1,1. It uses separate SI (MOSI) and SO (MISO) lines, supports CS-driven slave selection, and complies with SPI timing requirements including setup/hold times and clock polarity/phase - all verified in DS21204E AC Characteristics Tables 1-2 and Figures 1-2/1-3.
25AA040X-I/ST Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-TSSOP (0.173", 4.40mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- EEPROM
- Technology:
- EEPROM
- Memory Size:
- 4Kbit
- Memory Organization:
- 512 x 8
- Memory Interface:
- SPI
- Clock Frequency:
- 1 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-TSSOP
25AA040X-I/ST FAQ
1.How can I place an order for 25AA040X-I/ST through Aetrix?
Please submit a Request for Quotation (RFQ) for 25AA040X-I/ST 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 25AA040X-I/ST reliable?
The price and inventory of 25AA040X-I/ST are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 25AA040X-I/ST is usually 5 days.
3.What payment methods are accepted for 25AA040X-I/ST?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 25AA040X-I/ST transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 25AA040X-I/ST?
25AA040X-I/ST orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 25AA040X-I/ST 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 25AA040X-I/ST?
For technical support, including 25AA040X-I/ST datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 25AA040X-I/ST requirements.
6.How does Aetrix verify that 25AA040X-I/ST is sourced from the original manufacturer or authorized distributors?
All 25AA040X-I/ST 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 25AA040X-I/ST meets industry standards.
7.What is the process for return or replacement of 25AA040X-I/ST?
All 25AA040X-I/ST units undergo pre-shipment inspection (PSI). If there is an issue with 25AA040X-I/ST, 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 25AA040X-I/ST part is unused and in its original packaging.
Return procedure for 25AA040X-I/ST:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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