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Microchip Technology 25LC040AT-E/MS
- Part No.:
- 25LC040AT-E/MS
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
25LC040AT-E/MS.pdf
- Description:
- IC EEPROM 4KBIT SPI 10MHZ 8MSOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,001
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Product details
Overview
25LC040AT-E/MS from Microchip Technology Inc. is a 4 Kbit SPI Serial EEPROM with 512 × 8-bit organization, 16-byte page write capability, and industrial-temperature operation (–40°C to +85°C). It supports up to 10 MHz clock frequency at 4.5–5.5 V, features hardware write protection via WP pin, and delivers 1 million erase/write cycles with >200-year data retention. It is used in microcontroller-based systems for storing calibration data, configuration settings, and firmware parameters.
For engineers reviewing the 25LC040AT-E/MS datasheet, 25LC040AT-E/MS pinout, 25LC040AT-E/MS application, or 25LC040AT-E/MS equivalent, key selection criteria include SPI interface compatibility, 2.5–5.5 V supply range, MSOP-8 package footprint, block-level write protection (BP0/BP1), and HOLD functionality for interrupt-safe serial communication.
Technical Context
The 25LC040AT-E/MS 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, and optional HOLD. Its internal architecture includes an 8-bit instruction register, status register with WIP/WEL/BP bits, and page latches enabling up to 16-byte writes within a single 16-byte physical page boundary.
Write operations require explicit WREN instruction followed by CS high to latch enable state; subsequent WRITE commands must stay within page-aligned boundaries to avoid wraparound. The device supports sequential read, self-timed internal write cycles (≤5 ms), and power-on reset of the write enable latch - all critical for robust embedded firmware storage.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 4 Kbit (512 × 8-bit array), sufficient for small configuration tables or sensor calibration offsets in space-constrained designs. |
| Interface | SPI-compatible serial bus (Mode 0,0 / Mode 1,1), requiring only CS, SCK, SI, SO, WP, HOLD - minimal GPIO usage on host MCU. |
| Max Clock Frequency | 10 MHz at VCC ≥ 4.5 V, enabling fast read/write transfers (e.g., ~1.6 µs per byte at max speed) without demanding MCU timing margins. |
| Write Cycle Time | ≤5 ms per byte or page, deterministic internal timing eliminates need for external delay loops during firmware updates. |
| Endurance & Retention | 1,000,000 erase/write cycles and >200 years data retention at 25°C, validated for long-life industrial logging and field-upgrade applications. |
| Supply Voltage Range | 2.5 V to 5.5 V, compatible with both 3.3 V and 5 V logic domains - no level-shifting required in mixed-voltage systems. |
| Operating Temperature | –40°C to +85°C (Industrial grade), qualified for deployment in automotive body control modules and industrial PLC I/O expanders. |
Pinout & Package
25LC040AT-E/MS is housed in an 8-lead MSOP package (3.0 mm × 4.9 mm, 0.65 mm pitch), optimized for high-density PCB layouts and automated assembly. Pin 1 is marked by laser indentation at top-left corner.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS (Pin 1) | Chip Select Input | Active-low enable signal; drives device into active mode and initiates internal write cycle on rising edge after valid command sequence. |
| SO (Pin 2) | Serial Data Output | Tri-state output delivering memory contents on falling edge of SCK; high-impedance when CS high or HOLD low. |
| WP (Pin 3) | Write-Protect Input | Hardware lock: low disables all writes to memory and STATUS register regardless of WEL state - failsafe against voltage glitch corruption. |
| VSS (Pin 4) | Ground Reference | Primary return path for all internal circuitry; must be connected to system ground plane with low-inductance routing. |
| SI (Pin 5) | Serial Data Input | Accepts instructions, addresses, and data on rising edge of SCK; sampled synchronously to avoid metastability in noisy environments. |
| SCK (Pin 6) | Serial Clock Input | Master-generated clock controlling all data transfers; rise/fall times ≤100 ns required for reliable timing at 10 MHz. |
| HOLD (Pin 7) | Hold Input | Pauses ongoing SPI transaction (e.g., during MCU interrupt servicing); requires low-to-high transition while SCK is low to resume. |
| VCC (Pin 8) | Supply Voltage | Power input for core logic and EEPROM array; bypass capacitor (0.1 µF ceramic) required within 5 mm of this pin. |
Key Features
| Feature | Design Value |
|---|---|
| Page Write Mode (16 bytes) | Reduces firmware update time by up to 16× vs. byte-write; requires software enforcement of page-aligned address boundaries to prevent data wrap. |
| Block Write Protection (BP0/BP1) | Four configurable protection levels (none, upper 1/4, upper 1/2, or full array) stored nonvolatilely in STATUS register - enables secure boot code partitioning. |
| HOLD Functionality | Enables deterministic pause/resume of SPI transfers without reinitializing CS or losing internal address pointer state - critical for real-time interrupt handling. |
| Power-On Write Disable | Write enable latch resets automatically at power-up, preventing spurious writes during brown-out or supply ramp - eliminates need for external POR circuitry. |
| ESD Robustness | ≥4 kV HBM rating on all pins ensures reliability in manual handling and board-level ESD events without additional protection components. |
Applications
| Industrial Sensor Calibration | Automotive Body Control Module |
|---|---|
Use Scenario: Storing factory-trimmed offset/gain coefficients for analog sensor front-ends in programmable logic controllers. IC Role / Device Role / Timing Role: Nonvolatile configuration storage accessed once per power cycle during ADC initialization. Use Value: Enables field-replaceable sensor modules without recalibration; 1M endurance supports lifetime recalibration during maintenance. |
Use Scenario: Holding seat position memory, mirror angle presets, and lighting configuration in vehicle door modules. IC Role / Device Role / Timing Role: SPI-connected parameter store interfaced to 8-bit automotive MCU with limited internal NVM. Use Value: Survives 125°C under-hood thermal cycling; WP pin prevents accidental overwrites during CAN bus firmware updates. |
| Medical Device Configuration | Smart Energy Meter Firmware Patch |
Use Scenario: Saving user-defined alarm thresholds and operational modes in portable diagnostic equipment. IC Role / Device Role / Timing Role: Secure, low-power EEPROM accessed via SPI during GUI setup or battery-backed sleep wake-up. Use Value: <2 µA standby current extends battery life; >200-year retention meets FDA long-term device traceability requirements. |
Use Scenario: Storing delta patches applied to main flash firmware during remote OTA updates in utility meters. IC Role / Device Role / Timing Role: Dedicated patch storage buffer decoupled from main program memory to enable atomic update rollback. Use Value: Page write mode allows full 16-byte patch blocks to be written in one atomic operation, reducing risk of partial corruption. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar SPI EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 25AA040AT-I/MS | Wider VCC range (1.8–5.5 V); same pinout, timing, and memory map; lower 1.8 V operation enables direct interface with ultra-low-power MCUs. | Preferred for battery-powered IoT nodes where supply may dip below 2.5 V; not rated for automotive temperature range. | Select when operating below 2.5 V is required; verify hold-time and setup-time margins at 1.8 V per DS21827H Table 1-2. |
| AT25040B-MAU-T | Same 4 Kbit density and MSOP-8 package; supports 20 MHz clock (at 5 V); different status register bit layout and write-protection scheme. | Higher-speed read/write useful in high-throughput data loggers; requires firmware adaptation for status polling and BP bit handling. | Choose for performance-critical applications needing faster access; confirm compatibility of HOLD timing and WP behavior with existing driver stack. |
Compared with 25LC040AT-E/MS, the 25AA040AT-I/MS offers broader voltage flexibility but lacks automotive temp qualification, while the AT25040B-MAU-T provides higher bandwidth at the cost of firmware porting effort - making 25LC040AT-E/MS optimal for cost-sensitive industrial designs requiring guaranteed –40°C to +85°C operation and drop-in Microchip ecosystem support.
Availability
25LC040AT-E/MS is available at Aetrix Electronics and suitable for industrial automation, automotive subsystems, and medical instrumentation requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.
Supply support for 25LC040AT-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 devices, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.
The 25LC040A family was designed specifically for reliable, low-pin-count nonvolatile storage in resource-constrained embedded systems - emphasizing SPI simplicity, robust write protection, and extended endurance for mission-critical firmware and calibration data.
FAQ
What is the maximum clock frequency supported by the 25LC040AT-E/MS?
The 25LC040AT-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 it is not rated - though the 25LC040AT-E/MS is specified only down to 2.5 V per its datasheet. This graded timing ensures signal integrity across voltage ranges without requiring external clock dividers.
Does the 25LC040AT-E/MS support page write operations, and what is the page size?
Yes, the 25LC040AT-E/MS supports page write mode with a fixed page size of 16 bytes. Up to 16 consecutive bytes can be loaded into the page latch before initiating the internal write cycle. Writing across a 16-byte boundary causes wraparound within the same page - so firmware must validate address alignment prior to issuing the WRITE command to prevent unintended overwrites.
How does the WP pin function on the 25LC040AT-E/MS, and is it active-high or active-low?
The WP (Write-Protect) pin on the 25LC040AT-E/MS is active-low: when pulled to VSS (GND), it disables all write operations to both memory array and STATUS register, regardless of the WEL bit state. When held high (VCC), normal write functionality is restored. This hardware-level protection remains effective even during power transients, providing fail-safe data integrity.
What is the operating temperature range for the 25LC040AT-E/MS, and how is it designated in the part number?
The 25LC040AT-E/MS is rated for industrial temperature range: –40°C to +85°C. The "I" in the suffix denotes Industrial grade; the "E" in "25LC040A" refers to the automotive-grade variant (25LC040A-E), but the specific part number 25LC040AT-E/MS uses "T" for tape-and-reel packaging and "E" in the base type indicates eligibility for extended temp screening - however, per DS21827H Device Selection Table, this MSOP variant is specified for Industrial (I) range only.
Can the 25LC040AT-E/MS be used with 3.3 V microcontrollers, and what are the voltage compatibility considerations?
Yes, the 25LC040AT-E/MS operates fully within 2.5–5.5 V, making it directly compatible with standard 3.3 V logic systems. Its VIH threshold is 0.7×VCC (min), so at 3.3 V it accepts ≥2.31 V as high - comfortably above typical 3.3 V MCU VOH. VOL is ≤0.4 V at IOL = 2.1 mA, ensuring clean low-level recognition. No level-shifting is needed for SPI signals.
25LC040AT-E/MS Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Packaging:
- Tape & Reel (TR)
- 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
25LC040AT-E/MS FAQ
1.How can I place an order for 25LC040AT-E/MS through Aetrix?
Please submit a Request for Quotation (RFQ) for 25LC040AT-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 25LC040AT-E/MS reliable?
The price and inventory of 25LC040AT-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 25LC040AT-E/MS is usually 5 days.
3.What payment methods are accepted for 25LC040AT-E/MS?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 25LC040AT-E/MS transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 25LC040AT-E/MS?
25LC040AT-E/MS orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 25LC040AT-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 25LC040AT-E/MS?
For technical support, including 25LC040AT-E/MS datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 25LC040AT-E/MS requirements.
6.How does Aetrix verify that 25LC040AT-E/MS is sourced from the original manufacturer or authorized distributors?
All 25LC040AT-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 25LC040AT-E/MS meets industry standards.
7.What is the process for return or replacement of 25LC040AT-E/MS?
All 25LC040AT-E/MS units undergo pre-shipment inspection (PSI). If there is an issue with 25LC040AT-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 25LC040AT-E/MS part is unused and in its original packaging.
Return procedure for 25LC040AT-E/MS:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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