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Microchip Technology 25LC040A-E/MS
- Part No.:
- 25LC040A-E/MS
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
25LC040A-E/MS.pdf
- Description:
- IC EEPROM 4KBIT SPI 10MHZ 8MSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,330
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Product details
Overview
25LC040A-E/MS from Microchip Technology is a 4 Kbit (512 × 8) SPI serial EEPROM with 16-byte page write capability, 10 MHz max clock frequency at 4.5–5.5 V, and automotive-grade temperature support (−40°C to +125°C). It features hardware write protection (WP pin), HOLD suspend functionality, and block-level array protection (none/¼/½/all). Used for nonvolatile parameter storage in engine control units, battery management systems, and industrial sensor calibration.
For engineers reviewing the 25LC040A-E/MS datasheet, 25LC040A-E/MS pinout, 25LC040A-E/MS application, or 25LC040A-E/MS equivalent, key selection criteria include its 2.5–5.5 V VCC range, 5 µA standby current at +125°C, 1 M endurance cycles, >200-year data retention, and MSOP-8 package compatibility with space-constrained automotive PCBs.
Technical Context
The 25LC040A-E/MS implements a standard SPI Mode 0,0/Master-Slave interface with separate SI (MOSI) and SO (MISO) lines, requiring CS, SCK, WP, HOLD, VCC, and VSS. Its internal architecture includes a 512-byte EEPROM array, page latches, status register (WIP/WEL/BP0/BP1), and HV generator for write/erase operations.
Write operations require explicit WREN instruction followed by CS high to initiate self-timed internal write cycle (≤5 ms); read operations support sequential addressing with automatic address roll-over. The HOLD pin suspends ongoing transfers without resetting the sequence, enabling host interrupt servicing while preserving bus state.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 4 Kbit (512 × 8 bits) - stores firmware configuration, calibration coefficients, or fault logs in embedded controllers. |
| Interface | SPI-compatible serial bus (Mode 0,0) - interoperable with PIC® MCU SPI peripherals and generic GPIO bit-banged implementations. |
| Max Clock Frequency | 10 MHz at VCC ≥ 4.5 V - enables fast parameter reads during boot or diagnostics without CPU bus contention. |
| Page Write Size | 16 bytes per page - minimizes write latency when updating multi-byte settings (e.g., PID tuning tables). |
| Endurance | 1,000,000 erase/write cycles - supports frequent logging in telematics or battery cycle counters over 10+ years. |
| Data Retention | >200 years at +25°C - ensures long-term reliability of stored calibration data across product lifetime. |
| Operating Temp | −40°C to +125°C (Automotive E grade) - qualified for under-hood and powertrain applications per AEC-Q100 stress requirements. |
Pinout & Package
25LC040A-E/MS is housed in an 8-lead MSOP (Mini Small Outline Package) with 0.65 mm pitch, 3.0 mm × 3.0 mm body, and exposed pad (optional VSS connection). Pin 1 marked by laser dot; pin numbering follows standard MSOP convention.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS (Pin 1) | Chip Select Input | Active-low enable: drives device into active mode; rising edge initiates internal write cycle after valid command. |
| SO (Pin 2) | Serial Data Output | MISO line: outputs memory data on falling SCK edge; tri-states when CS high or HOLD low. |
| WP (Pin 3) | Write-Protect Input | Hardware lock: disables all writes (array and STATUS) when pulled low; overrides WEL state. |
| VSS (Pin 4) | Ground Reference | Primary return path for I/O and core logic; exposed pad may be connected to VSS for thermal/mechanical stability. |
| SI (Pin 5) | Serial Data Input | MOSI line: accepts instructions, addresses, and write data on rising SCK edge; sampled after CS low. |
| SCK (Pin 6) | Serial Clock Input | Master-generated clock: synchronizes all data transfers; rise/fall times ≤100 ns required for 10 MHz operation. |
| HOLD (Pin 7) | Hold Input | Suspends ongoing SPI transfer: must be asserted low while SCK is low to avoid bus corruption. |
| VCC (Pin 8) | Supply Voltage | 2.5–5.5 V operating range: supports direct connection to 3.3 V or 5 V microcontroller I/O rails without level shifting. |
Key Features
| Feature | Design Value |
|---|---|
| Block Write Protection | Selective 0%/25%/50%/100% array protection via BP0/BP1 bits - prevents accidental overwrite of critical bootloader or safety-critical parameters. |
| Self-Timed Write Cycle | ≤5 ms internal erase/write completion - eliminates need for external timing delays; WIP bit polling confirms readiness. |
| Power-On Write Disable | WEL reset at power-up - ensures EEPROM remains read-only until firmware explicitly enables writes, preventing corruption during brown-out. |
| HOLD Functionality | Bus pause/resume without reinitialization - allows microcontroller to service higher-priority interrupts (e.g., CAN error frames) mid-transfer. |
| ESD Robustness | >4 kV HBM on all pins - withstands handling and board-level ESD events in automotive manufacturing and field repair environments. |
Applications
| Engine Control Unit (ECU) | Industrial PLC Configuration |
|---|---|
Use Scenario: Storing adaptive fuel trim values, knock sensor thresholds, and diagnostic trouble codes (DTCs) that persist across ignition cycles. IC Role / Device Role / Timing Role: Nonvolatile parameter storage with deterministic 5 ms write latency and guaranteed data integrity during voltage transients. Use Value: Enables closed-loop engine optimization and regulatory-compliant OBD-II logging without external backup capacitors or supervisory ICs. |
Use Scenario: Holding user-defined I/O mapping, PID controller gains, and alarm setpoints in modular automation controllers. IC Role / Device Role / Timing Role: SPI-configurable memory accessed during startup and runtime via real-time OS tasks. Use Value: Eliminates factory programming steps; allows field updates via HMI or engineering software without firmware reflashing. |
| Battery Management System (BMS) | Medical Infusion Pump Calibration |
Use Scenario: Recording cell voltage balancing history, cycle count, and thermal derating profiles across thousands of charge/discharge cycles. IC Role / Device Role / Timing Role: High-endurance data logger interfaced to ADC and MCU over shared SPI bus with HOLD support. Use Value: Supports ISO 26262 ASIL-B functional safety requirements through verified 1M-cycle endurance and >200-year retention. |
Use Scenario: Storing flow rate calibration coefficients, motor step compensation tables, and usage audit logs traceable to FDA 21 CFR Part 11. IC Role / Device Role / Timing Role: Secure, tamper-resistant memory with hardware WP pin and block protection for regulatory compliance. Use Value: Meets medical device data integrity mandates without requiring cryptographic co-processors or external secure elements. |
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/MS | Wider VCC range (1.8–5.5 V); Industrial temp only (−40°C to +85°C); identical pinout and instruction set. | Not qualified for automotive under-hood use; suitable for consumer/industrial products with lower voltage rails. | Select 25AA040A-I/MS only if operating below 2.5 V or outside automotive temperature requirements. |
| AT25040B-MAHL-T | Same 4 Kbit SPI EEPROM, but with 20 MHz max clock, 1.8–5.5 V supply, and different STATUS register layout (no BP bits). | Lacks hardware block protection; requires software-managed write locking; not AEC-Q100 qualified. | Choose AT25040B-MAHL-T only when higher speed is critical and hardware write protection is unnecessary. |
Compared with 25AA040A-I/MS, the 25LC040A-E/MS trades wider voltage flexibility for automotive qualification and hardware-based block protection; versus AT25040B-MAHL-T, it prioritizes safety-critical write security and temperature robustness over raw speed.
Availability
25LC040A-E/MS is available at Aetrix Electronics and suitable for automotive powertrain control, industrial programmable logic controllers, and medical device calibration requiring stable component supply across extended product lifecycles.
Supply support for 25LC040A-E/MS 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 25LC040A belongs to Microchip's serial EEPROM product line, engineered specifically for automotive and industrial applications demanding high reliability, extended temperature operation, and robust data integrity under electrical stress.
FAQ
What is the maximum clock frequency supported by the 25LC040A-E/MS?
The 25LC040A-E/MS supports up to 10 MHz clock frequency when VCC is between 4.5 V and 5.5 V. At 2.5–4.5 V, the maximum clock drops to 5 MHz, and at 1.8–2.5 V (not applicable to this E-grade part), it is 3 MHz. These limits ensure reliable setup/hold timing across voltage and temperature ranges.
Does the 25LC040A-E/MS require external pull-up resistors on SI, SO, or SCK lines?
No, the 25LC040A-E/MS does not require external pull-ups on SI, SO, or SCK. Its inputs (CS, WP, HOLD, SI) have internal weak pull-downs, and SO is actively driven or tri-stated. Pull-ups are only needed if bus sharing with open-drain devices or specific noise immunity requirements dictate them.
How does the HOLD function behave during an active write cycle in the 25LC040A-E/MS?
The HOLD pin has no effect during an internal write cycle (TWC) in the 25LC040A-E/MS. Once CS rises to initiate the 5 ms self-timed write, the device ignores HOLD transitions until the cycle completes. HOLD only suspends ongoing SPI communication - not internal flash operations.
Can the 25LC040A-E/MS be used with a 1.8 V microcontroller SPI interface?
No, the 25LC040A-E/MS requires a minimum VCC of 2.5 V and is not rated for 1.8 V operation. For 1.8 V systems, consider the 25AA040A-I/MS variant, which supports 1.8–5.5 V but lacks automotive temperature qualification and has different DC characteristics.
What happens to the write enable latch (WEL) after a successful write operation in the 25LC040A-E/MS?
In the 25LC040A-E/MS, the write enable latch (WEL) is automatically reset after any successful WRITE, WRSR, or WRDI instruction, or when WP is pulled low. This ensures write operations are never enabled by default after power-up or incomplete sequences, enforcing safe-by-default behavior.
25LC040A-E/MS Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Programmable:
- Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- EEPROM
- Technology:
- EEPROM
- Memory Size:
- 4Kbit
- Memory Organization:
- 512 x 8
- Memory Interface:
- SPI
- Clock Frequency:
- 10 MHz
- Write Cycle Time - Word, Page:
- 5ms
- Access Time:
- -
- Voltage - Supply:
- 2.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-MSOP
25LC040A-E/MS FAQ
1.How can I place an order for 25LC040A-E/MS through Aetrix?
Please submit a Request for Quotation (RFQ) for 25LC040A-E/MS 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 25LC040A-E/MS reliable?
The price and inventory of 25LC040A-E/MS are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 25LC040A-E/MS is usually 5 days.
3.What payment methods are accepted for 25LC040A-E/MS?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 25LC040A-E/MS transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 25LC040A-E/MS?
25LC040A-E/MS orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 25LC040A-E/MS 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 25LC040A-E/MS?
For technical support, including 25LC040A-E/MS datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 25LC040A-E/MS requirements.
6.How does Aetrix verify that 25LC040A-E/MS is sourced from the original manufacturer or authorized distributors?
All 25LC040A-E/MS 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 25LC040A-E/MS meets industry standards.
7.What is the process for return or replacement of 25LC040A-E/MS?
All 25LC040A-E/MS units undergo pre-shipment inspection (PSI). If there is an issue with 25LC040A-E/MS, 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 25LC040A-E/MS part is unused and in its original packaging.
Return procedure for 25LC040A-E/MS:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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