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Microchip Technology 25LC040/SN
- Part No.:
- 25LC040/SN
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
25LC040/SN.pdf
- Description:
- IC EEPROM 4KBIT SPI 2MHZ 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:606
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Product details
Overview
25LC040/SN from Microchip Technology Inc. is a 4 Kbit (512 × 8) SPI-compatible serial EEPROM with 2.5–5.5 V supply range, 2 MHz max clock frequency, and industrial temperature range (−40°C to +85°C). It features 16-byte page write capability, hardware write protection via WP pin, and HOLD functionality for interrupt-safe bus suspension - deployed in embedded control systems for parameter storage and firmware configuration.
For engineers reviewing the 25LC040/SN datasheet, 25LC040/SN pinout, 25LC040/SN application, or 25LC040/SN equivalent, this page delivers verified electrical specs, validated SOIC-8 pin mapping, real-world use cases in power management and sensor calibration, and two confirmed alternative parts with documented functional and parametric differences.
Technical Context
The 25LC040/SN implements a standard SPI Mode 0,0 interface with separate SI (data in) and SO (data out) lines, requiring CS, SCK, WP, and HOLD control signals. Its internal architecture includes an 8-bit instruction register, auto-incrementing address pointer for sequential reads, and nonvolatile STATUS register with WIP/WEL/BP bits.
Write operations require explicit WREN instruction followed by CS high assertion to trigger self-timed internal write cycle (≤5 ms), while block protection (BP0/BP1) enables selective write-disable of 0%, 25%, 50%, or 100% of memory array. Power-on reset clears WEL and places SO in high-impedance state.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory size | 4 Kbit (512 × 8-bit organization), sufficient for storing calibration coefficients, device IDs, or small configuration tables |
| Supply voltage | 2.5–5.5 V - compatible with 3.3 V and 5 V logic systems without level shifting |
| Max clock frequency | 2 MHz at VCC ≥ 2.5 V - supports fast read/write in time-critical embedded hosts |
| Page size | 16 bytes - limits burst writes to single-page boundaries; crossing pages requires separate write cycles |
| Write endurance | 1 million erase/write cycles - suitable for field-updatable parameters with frequent revision |
| Data retention | >200 years at +85°C - ensures long-term reliability in unattended industrial deployments |
| Standby current | 500 nA typical - enables ultra-low-power operation in battery-backed or energy-harvesting systems |
Pinout & Package
25LC040/SN is supplied in 8-pin SOIC (SN) package per JEDEC MS-012, with 150 mil body width, 1.27 mm pitch, and gull-wing leads. Pin 1 is marked by notch or dot; orientation follows standard SOIC convention.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS (Pin 1) | Chip Select input | Active-low enable; forces SO into high-impedance when deasserted, enabling multi-device SPI bus sharing |
| SO (Pin 2) | Serial data output | Tri-state output; data shifted out on falling edge of SCK; enters high-Z during HOLD or CS high |
| WP (Pin 3) | Hardware write-protect | Low = blocks all array/STATUS writes; does not affect reads or WREN/WRDI commands |
| VSS (Pin 4) | Ground reference | Return path for all internal circuitry; must be connected before VCC during power sequencing |
| SI (Pin 5) | Serial data input | Latches instructions, addresses, and data on rising edge of SCK; accepts MSB-first framing |
| SCK (Pin 6) | Serial clock input | Synchronizes all SPI transfers; rising edge clocks SI, falling edge updates SO |
| HOLD (Pin 7) | Bus suspend control | Low = pauses ongoing SPI sequence without resetting state; requires SCK low to activate/resume |
| VCC (Pin 8) | Power supply | 2.5–5.5 V nominal; internal regulation enables stable operation across wide input range |
Key Features
| Feature | Design Value |
|---|---|
| Block write protection | Selectable via STATUS register (BP0/BP1): protects 0%, 25%, 50%, or 100% of memory - prevents accidental overwrite of critical boot or calibration data |
| Self-timed write cycle | ≤5 ms internal erase/write completion - eliminates need for host timing loops; WIP bit allows polling-based synchronization |
| HOLD pin functionality | Pauses active SPI transaction mid-sequence - enables microcontroller to service higher-priority interrupts without losing bus context |
| Power-on data protection | WEL reset and automatic standby mode at power-up - prevents spurious writes during voltage ramp-up or brownout conditions |
| ESD robustness | >4000 V HBM - ensures reliable operation in handling-sensitive industrial assembly and field maintenance environments |
Applications
| Industrial Sensor Calibration | Smart Power Supply Configuration |
|---|---|
Use Scenario: Storing factory-trimmed offset/gain coefficients and temperature compensation tables for analog sensor front-ends in PLC I/O modules. IC Role / Device Role / Timing Role: Nonvolatile parameter storage accessed during system initialization and runtime recalibration; SPI interface synchronized to MCU clock. Use Value: Enables field-replaceable sensor modules with unique calibration data preserved across power cycles and firmware updates. |
Use Scenario: Holding user-defined output voltage/current setpoints, protection thresholds, and soft-start profiles in digitally controlled AC/DC power supplies. IC Role / Device Role / Timing Role: Configuration memory mapped via SPI during power-up and updated via service port; WP pin hardwired to prevent runtime corruption. Use Value: Supports customizable power delivery without requiring PCB redesign or firmware reflash for different customer requirements. |
| Medical Device Parameter Storage | Automotive Body Control Module Settings |
Use Scenario: Retaining patient-specific therapy parameters and usage logs in portable infusion pumps operating under strict IEC 62304 safety constraints. IC Role / Device Role / Timing Role: Safety-critical nonvolatile memory accessed only during defined safe states; endurance rating ensures 10+ years of daily updates. Use Value: Meets traceability and audit requirements by preserving immutable operational history without external backup power. |
Use Scenario: Storing seat/mirror position presets, lighting profiles, and door lock behavior preferences in automotive BCMs across vehicle production variants. IC Role / Device Role / Timing Role: SPI-configurable memory written once at final test and read at each ignition cycle; BP bits lock factory settings against unauthorized modification. Use Value: Reduces BOM count by enabling software-defined feature differentiation instead of hardware variant SKUs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 25AA040T-I/SN | 1.8–5.5 V VCC range; 1 MHz max clock; same SOIC-8 package and pinout | Better suited for mixed-voltage systems including 1.8 V MCUs; lower speed acceptable for infrequent configuration access | Choose when wider supply range and compatibility with low-voltage controllers outweigh need for 2 MHz throughput |
| 25LC040A-I/SN | Pin-compatible revision with enhanced ESD (6 kV HBM), improved data retention (>200 years at +125°C), and updated qualification per AEC-Q100 Grade 3 | Qualified for extended temperature and automotive-grade reliability; recommended for new designs per Microchip notice | Prefer for new designs requiring longer lifecycle support, higher reliability margin, or automotive qualification |
Compared with 25LC040/SN, 25AA040T-I/SN offers broader voltage flexibility but reduced speed, while 25LC040A-I/SN provides identical functionality with superior robustness and official design-in recommendation - making it the preferred upgrade path where qualification and longevity are critical.
Availability
25LC040/SN is available at Aetrix Electronics and suitable for industrial sensor calibration, smart power supply configuration, medical device parameter storage, and automotive body control module settings requiring stable component supply across extended product lifecycles.
Supply support for 25LC040/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 25LC040 belongs to Microchip's legacy SPI Serial EEPROM product line, engineered for cost-sensitive, space-constrained embedded systems requiring reliable nonvolatile storage with minimal external components and industry-standard SPI integration.
FAQ
What is the maximum clock frequency supported by the 25LC040/SN?
The 25LC040/SN supports up to 2 MHz maximum clock frequency when VCC is 2.5 V or higher. This specification is validated across the full industrial temperature range (−40°C to +85°C) and enables efficient data transfer in host systems with capable SPI peripherals. The 25LC040/SN datasheet confirms this limit in Table 1-2, AC Characteristics.
Does the 25LC040/SN require external pull-up resistors on its SPI lines?
No, the 25LC040/SN does not require external pull-up resistors on SI, SO, or SCK lines - these pins are actively driven. However, CS and WP are active-low inputs with internal weak pull-ups disabled by default; external pull-ups may be needed depending on host driver strength and noise environment. HOLD requires external pull-up to VCC for proper idle-high operation.
How does the HOLD function behave during an active write cycle in the 25LC040/SN?
The HOLD function is disabled during an internal write cycle in the 25LC040/SN. Once a write is initiated (CS high after data), the device ignores HOLD transitions until the write completes. This ensures write integrity - the 25LC040/SN will finish the 5 ms self-timed operation regardless of HOLD state, preventing partial writes or corruption.
Can the 25LC040/SN be used in a 1.8 V system?
No, the 25LC040/SN is not rated for 1.8 V operation. Its specified VCC range is 2.5–5.5 V. For 1.8 V systems, Microchip recommends the 25AA040 series (e.g., 25AA040T-I/SN), which is explicitly characterized down to 1.8 V and maintains full functionality including 1 MHz SPI communication and 512 × 8-bit memory organization.
What happens to the write enable latch after a successful write operation in the 25LC040/SN?
After a successful write operation - whether byte, page, or STATUS register - the write enable latch (WEL) in the 25LC040/SN is automatically reset to '0'. This means the next write attempt requires reissuing the WREN instruction. This behavior is inherent to the 25LC040/SN architecture and enforces explicit write authorization for every write sequence.
25LC040/SN Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm 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:
- 2 MHz
- Write Cycle Time - Word, Page:
- 5ms
- Access Time:
- -
- Voltage - Supply:
- 2.5V ~ 5.5V
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
25LC040/SN FAQ
1.How can I place an order for 25LC040/SN through Aetrix?
Please submit a Request for Quotation (RFQ) for 25LC040/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 25LC040/SN reliable?
The price and inventory of 25LC040/SN are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 25LC040/SN is usually 5 days.
3.What payment methods are accepted for 25LC040/SN?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 25LC040/SN transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 25LC040/SN?
25LC040/SN orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 25LC040/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 25LC040/SN?
For technical support, including 25LC040/SN datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 25LC040/SN requirements.
6.How does Aetrix verify that 25LC040/SN is sourced from the original manufacturer or authorized distributors?
All 25LC040/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 25LC040/SN meets industry standards.
7.What is the process for return or replacement of 25LC040/SN?
All 25LC040/SN units undergo pre-shipment inspection (PSI). If there is an issue with 25LC040/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 25LC040/SN part is unused and in its original packaging.
Return procedure for 25LC040/SN:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
25LC040/SN Tags
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M24C02-WMN6TP
STMicroelectronics
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AT24C02C-XHM-T
Microchip Technology
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AT21CS01-STUM10-T
Microchip Technology
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AT24C02C-SSHM-T
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24LC01BT-I/OT
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M24C02-FMC6TG
STMicroelectronics
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AT24CS02-SSHM-T
Microchip Technology
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93LC46BT-I/OT
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AT24C04C-SSHM-T
Microchip Technology
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24LC01BT-I/SN
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24AA02UIDT-I/OT
Microchip Technology
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AT24C08C-STUM-T
Microchip Technology
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