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Microchip Technology 25LC040AT-E/SN
- Part No.:
- 25LC040AT-E/SN
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
25LC040AT-E/SN.pdf
- Description:
- IC EEPROM 4KBIT SPI 10MHZ 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,921
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Product details
Overview
25LC040AT-E/SN from Microchip Technology Inc. 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 industrial/automotive 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 firmware parameter storage in automotive control modules.
For engineers reviewing the 25LC040AT-E/SN datasheet, 25LC040AT-E/SN pinout, 25LC040AT-E/SN application, or 25LC040AT-E/SN equivalent, key selection criteria include VCC range (2.5–5.5 V), page write timing (≤5 ms), endurance (1 million cycles), data retention (>200 years), and SOIC-8 (SN) package compatibility with legacy SPI bus designs.
Technical Context
The 25LC040AT-E/SN implements a standard SPI Mode 0,0/Master-Slave interface with separate SI (data in) and SO (data out) lines, requiring CS, SCK, WP, HOLD, VCC, and VSS. Its internal architecture includes a 9-bit address counter, page latches, and a nonvolatile STATUS register controlling BP0/BP1 block protection bits and WEL/WIP flags.
Write operations require explicit WREN instruction followed by CS high-to-low transition to initiate self-timed internal write cycle (TWC ≤ 5 ms); reads support sequential addressing with automatic rollover at 1FFh. HOLD suspends ongoing transfers while preserving internal state, enabling interrupt servicing without reinitialization.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 4 Kbit (512 × 8 bits) - supports small configuration tables or calibration data in space-constrained embedded systems. |
| Interface | SPI-compatible serial bus (Mode 0,0) - interoperable with PIC® and other MCU SPI peripherals without protocol translation. |
| Max Clock Frequency | 10 MHz at VCC ≥ 4.5 V - enables fast read/write bursts in real-time control loops. |
| Page Write Size | 16 bytes per page - reduces write overhead vs. byte-wise writes; requires software boundary checking to avoid wraparound. |
| Endurance & Retention | 1,000,000 erase/write cycles; >200 years data retention - suitable for infrequently updated but mission-critical settings (e.g., vehicle VIN storage). |
| VCC Range | 2.5 V to 5.5 V - compatible with both 3.3 V and 5 V logic domains, simplifying power domain integration. |
| Temp Range | −40°C to +125°C (Automotive E grade) - qualified for under-hood and powertrain applications per AEC-Q100 requirements. |
Pinout & Package
25LC040AT-E/SN is packaged in an 8-lead SOIC (SN) with 150 mil width, RoHS-compliant matte tin finish, and standard JEDEC MS-012AC footprint. Pin 1 marked by laser dot; pin 1 ID corner indicated by beveled edge.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS (Pin 1) | Chip Select Input | Active-low enable; must go high after final data bit to trigger internal write cycle; deselects device into high-Z SO state. |
| SO (Pin 2) | Serial Data Output | Tri-state output; data valid on falling SCK edge; enters high-impedance when CS high or HOLD low. |
| WP (Pin 3) | Hardware Write-Protect | Low = all writes inhibited (array + STATUS); overrides WEL; does not abort in-progress writes. |
| VSS (Pin 4) | Ground Reference | Return path for all I/O and core logic; must be low-impedance connection to minimize noise coupling. |
| SI (Pin 5) | Serial Data Input | Latches instruction/address/data on rising SCK edge; accepts MSb-first SPI framing including RDSR/WRSR commands. |
| SCK (Pin 6) | Serial Clock Input | Synchronizes all data transfers; rise/fall times ≤100 ns required for 10 MHz operation. |
| HOLD (Pin 7) | Transfer Suspend Control | Low = pauses active SPI sequence; SO/SI/SCK tri-stated; resumes from exact point on HOLD high (SCK low required). |
| VCC (Pin 8) | Supply Voltage | 2.5–5.5 V operating range; decoupling capacitor (0.1 µF) required near pin for stable read/write margins. |
Key Features
| Feature | Design Value |
|---|---|
| Block Write Protection | BP0/BP1 bits in STATUS register allow selective protection of none, upper 1/4 (180h–1FFh), upper 1/2 (100h–1FFh), or entire array (000h–1FFh). |
| Power-On Write Safety | Write enable latch resets at power-up; WP pin low forces protection; prevents corruption during brown-out or reset sequences. |
| Hold Functionality | Enables host MCU to service higher-priority interrupts mid-transfer without losing context or retransmitting command sequences. |
| Self-Timed Internal Writes | 5 ms max write cycle eliminates need for external timing control; WIP bit polling via RDSR allows precise completion detection. |
| ESD Robustness | 4 kV HBM rating on all pins - enhances reliability in automotive assembly and field environments with high static potential. |
Applications
| Engine Control Unit (ECU) | Infotainment System Settings |
|---|---|
Use Scenario: Storing adaptive fuel trim values, fault codes, and calibration offsets that persist across ignition cycles. IC Role / Device Role / Timing Role: Nonvolatile parameter storage interfaced directly to ECU's SPI master port; accessed during boot and runtime diagnostics. Use Value: 1M-cycle endurance ensures >15 years of reliable updates under typical vehicle duty cycles; −40°C to +125°C rating matches engine bay thermal profile. | Use Scenario: Retaining user preferences (volume, EQ, display brightness) and Bluetooth pairing IDs across power-down events. IC Role / Device Role / Timing Role: SPI-configurable memory mapped to infotainment SoC's peripheral bus; read at startup, written on setting change. Use Value: Page write mode (16 B) minimizes update latency vs. byte writes; WP pin prevents accidental overwrites during firmware OTA updates. |
| Advanced Driver Assistance Systems (ADAS) | Industrial Motor Drive Firmware |
Use Scenario: Saving camera lens calibration coefficients and radar sensor alignment parameters after factory setup or field recalibration. IC Role / Device Role / Timing Role: Secure configuration store accessed only during initialization or maintenance mode; protected via BP bits against runtime corruption. Use Value: >200-year data retention guarantees parameter integrity over full vehicle lifetime; HOLD function allows safe interruption during CAN message processing. | Use Scenario: Holding motor commutation tables, PID tuning constants, and safety interlock states in variable-frequency drives. IC Role / Device Role / Timing Role: SPI EEPROM co-located with motor control MCU; updated during commissioning or field service via isolated debug interface. Use Value: 2.5–5.5 V VCC range interfaces seamlessly with 3.3 V control logic and 5 V analog sensing rails; SOIC-8 package enables automated PCB assembly. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 25AA040AT-I/SN | VCC range 1.8–5.5 V; Industrial temp only (−40°C to +85°C); same pinout and instruction set. | Not qualified for automotive under-hood use; lower minimum voltage enables battery-powered sensors. | Select when operating below 2.5 V or where automotive temp grade is unnecessary. |
| AT25040B-MAHL-T | Same 4 Kbit size, SPI interface, and SOIC-8 package; 2.5–5.5 V VCC; 1M endurance; but no HOLD pin. | Lacks suspend capability - unsuitable for interrupt-driven hosts requiring transfer pausing. | Choose if HOLD is unused and Atmel/Dialog supply chain preference applies. |
Compared with 25AA040AT-I/SN, the 25LC040AT-E/SN adds automotive temperature qualification and removes 1.8 V operation; versus AT25040B-MAHL-T, it retains HOLD functionality critical for deterministic real-time SPI arbitration - making it the only option supporting interrupt-safe parameter updates in safety-critical automotive nodes.
Availability
25LC040AT-E/SN is available at Aetrix Electronics and suitable for automotive control units, infotainment systems, and industrial motor drives requiring stable component supply with long-term lifecycle assurance.
Supply support for 25LC040AT-E/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 microcontroller, mixed-signal, analog, and Flash-IP solutions, serving automotive, industrial, consumer, and communications markets with high-reliability silicon and development tools.
The 25LC040A product line delivers SPI EEPROMs optimized for automotive-grade reliability, featuring extended temperature operation, robust ESD protection, and hardware-based write safeguards for mission-critical data storage.
FAQ
What is the maximum clock frequency supported by the 25LC040AT-E/SN?
The 25LC040AT-E/SN 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 part), it would be 3 MHz. These limits ensure reliable setup/hold timing for SI/SO transitions and internal state machine operation.
Does the 25LC040AT-E/SN have built-in write protection features beyond the WP pin?
Yes, the 25LC040AT-E/SN includes multiple write protection layers: the hardware WP pin (Pin 3), a volatile write-enable latch (WEL bit) set via WREN instruction, and nonvolatile block protection bits (BP0/BP1) in the STATUS register. These can be combined - e.g., WP high + BP1/BP0 = 11 protects the full array even if WEL is set.
How does the HOLD function operate in the 25LC040AT-E/SN during an active SPI transfer?
When HOLD is pulled low while SCK is low, the 25LC040AT-E/SN immediately suspends SPI communication: SI, SO, and SCK enter high-impedance states, and internal sequencing pauses. The device retains its current address and instruction state. Resuming requires bringing HOLD high while SCK remains low - then normal transfer continues from the exact bit position where it paused.
What package type is used for the 25LC040AT-E/SN, and what are its key mechanical features?
The 25LC040AT-E/SN uses an 8-lead SOIC (SN) package per JEDEC MS-012AC, 150 mil width, with matte tin (Pb-free) termination. It features a laser-marked pin 1 indicator, standard 1.27 mm lead pitch, and is optimized for reflow soldering. The SN suffix explicitly denotes this SOIC-8 variant.
Can the 25LC040AT-E/SN be used in systems powered by 3.3 V logic supplies?
Yes, the 25LC040AT-E/SN operates reliably from 2.5 V to 5.5 V, fully covering standard 3.3 V ±10% supply ranges. Its DC characteristics (e.g., VIH = 0.7×VCC, VOL = 0.4 V at 2.1 mA) and AC timing (5 MHz max at 2.5–4.5 V) are specified and tested across this range, ensuring interoperability with 3.3 V MCUs without level shifting.
25LC040AT-E/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:
- 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-SOIC
25LC040AT-E/SN FAQ
1.How can I place an order for 25LC040AT-E/SN through Aetrix?
Please submit a Request for Quotation (RFQ) for 25LC040AT-E/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 25LC040AT-E/SN reliable?
The price and inventory of 25LC040AT-E/SN 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/SN is usually 5 days.
3.What payment methods are accepted for 25LC040AT-E/SN?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 25LC040AT-E/SN transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 25LC040AT-E/SN?
25LC040AT-E/SN orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 25LC040AT-E/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 25LC040AT-E/SN?
For technical support, including 25LC040AT-E/SN datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 25LC040AT-E/SN requirements.
6.How does Aetrix verify that 25LC040AT-E/SN is sourced from the original manufacturer or authorized distributors?
All 25LC040AT-E/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 25LC040AT-E/SN meets industry standards.
7.What is the process for return or replacement of 25LC040AT-E/SN?
All 25LC040AT-E/SN units undergo pre-shipment inspection (PSI). If there is an issue with 25LC040AT-E/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 25LC040AT-E/SN part is unused and in its original packaging.
Return procedure for 25LC040AT-E/SN:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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