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Microchip Technology 25LC640T-I/SNG
- Part No.:
- 25LC640T-I/SNG
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
25LC640T-I/SNG.pdf
- Description:
- IC EEPROM 64KBIT SPI 2MHZ 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,238
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Product details
Overview
25LC640T-I/SNG from Microchip Technology Inc. is a 64 Kbit SPI Serial EEPROM with 8192 × 8-bit organization, 32-byte page write capability, and industrial temperature range (−40°C to +85°C). It operates at up to 2 MHz clock frequency with 2.5–5.5 V supply, features hardware write protection via WP pin and STATUS register, and supports HOLD for interrupt-safe serial communication. It is used in embedded systems for nonvolatile parameter storage in smart sensors and industrial controllers.
For engineers reviewing the 25LC640T-I/SNG datasheet, 25LC640T-I/SNG pinout, 25LC640T-I/SNG application, or 25LC640T-I/SNG equivalent, key selection criteria include SPI interface compatibility, 5 ms max write cycle time, 1 million endurance cycles, low standby current (500 nA), and TSSOP-8 package suitability for space-constrained PCB layouts.
Technical Context
The 25LC640T-I/SNG implements a standard SPI Mode 0,0/Multi-Master-compatible serial bus with separate SI (data in) and SO (data out) lines, CS-controlled device selection, and HOLD-driven pause/resume functionality. Its internal architecture includes an 8-bit instruction register, status register with WIP/WEL/BP0/BP1 bits, and high-voltage generator for EEPROM programming.
It supports four block protection levels (none, 1/4, 1/2, or full array) via BP0/BP1 bits, hardware write protection enabled only when WPEN=1 and WP=low, and automatic address pointer increment during sequential read. Write operations require explicit WREN instruction and CS high-to-low transition to initiate self-timed 5 ms internal erase/write cycle.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 64 Kbit (8192 × 8-bit) - provides sufficient nonvolatile storage for firmware configuration, calibration data, and event logs in resource-limited microcontroller systems. |
| Interface | SPI (Mode 0,0) - ensures plug-and-play compatibility with PIC, AVR, ARM Cortex-M, and other MCU families featuring native SPI peripherals. |
| Max Clock Frequency | 2 MHz at VCC = 2.5–5.5 V - enables fast read/write throughput (up to 32 bytes/page) without requiring high-speed MCU clock scaling. |
| Write Cycle Time | 5 ms maximum - defines worst-case latency for persistent data commit; critical for real-time logging and fail-safe state capture. |
| Data Retention | >200 years - guarantees long-term reliability of stored parameters across product lifecycle without refresh requirements. |
| Endurance | 1 million erase/write cycles - supports frequent updates in telemetry, metering, or adaptive control applications. |
| Supply Voltage | 2.5 V to 5.5 V - allows direct integration with 3.3 V and 5 V logic domains without level-shifting circuitry. |
| Standby Current | 500 nA typical - minimizes power budget impact in battery-powered or energy-harvesting edge devices. |
Pinout & Package
25LC640T-I/SNG is housed in an 8-lead TSSOP package (4.4 mm body width, JEDEC MO-153 compliant) with gull-wing leads, optimized for automated SMT assembly and compact board layout.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS (Pin 3) | Chip Select Input | Active-low enable signal; deselects device and places SO in high-impedance state to allow multi-device SPI bus sharing. |
| SO (Pin 4) | Serial Data Output | Tri-state output delivering memory contents MSB-first on falling edge of SCK; high-Z when CS high or HOLD active. |
| WP (Pin 5) | Write-Protect Input | Hardware lock for STATUS register nonvolatile bits when WPEN=1; no effect on array writes unless BP bits are set. |
| VSS (Pin 6) | Ground Reference | Primary return path for all internal circuitry and I/O; must be low-impedance connection to system ground plane. |
| SI (Pin 7) | Serial Data Input | Accepts instructions, addresses, and write data MSB-first on rising edge of SCK; latched synchronously to clock. |
| SCK (Pin 8) | Serial Clock Input | Master-generated clock controlling timing of all SPI transactions; rise/fall times ≤2 μs required for reliable operation. |
| HOLD (Pin 1) | Communication Pause Input | Active-low suspend signal; freezes ongoing SPI sequence without reset; requires SCK low before assertion/deassertion. |
| VCC (Pin 2) | Power Supply | 2.5–5.5 V operating voltage; bypass capacitor (0.1 μF ceramic) required within 10 mm of pin for noise immunity. |
Key Features
| Feature | Design Value |
|---|---|
| Page Write Capability | 32-byte burst writes within same page boundary (XXX0 0000–XXX1 1111) reduce transaction overhead vs. byte-by-byte programming. |
| Block Write Protection | Selectable protection of none, upper 1/4 (1800h–1FFFh), upper 1/2 (1000h–1FFFh), or full array (0000h–1FFFh) via BP0/BP1 bits. |
| Built-in Power-On Protection | Write enable latch resets at power-up, and WREN must be issued before any write - prevents spurious writes during brown-out conditions. |
| HOLD Functionality | Enables host MCU to service higher-priority interrupts mid-transaction; resumes from exact point without retransmission. |
| ESD Robustness | 4 kV HBM rating on all pins - enhances field reliability in industrial environments with frequent handling or cable hot-plug events. |
| Low-Voltage Operation | Functional down to 2.5 V VCC - supports direct interfacing with 3.3 V systems and extends battery life in portable instrumentation. |
Applications
| Smart Sensor Calibration Storage | Industrial PLC Configuration Memory |
|---|---|
|
Use Scenario: Storing factory-calibrated sensor offset/gain coefficients and temperature compensation tables in MEMS pressure or humidity sensors. IC Role / Device Role / Timing Role: Nonvolatile parameter repository accessed during power-up initialization and runtime correction routines via SPI. Use Value: Eliminates need for external calibration EEPROM; 200-year data retention ensures accuracy over product lifetime without recalibration. |
Use Scenario: Holding user-defined I/O mapping, PID loop parameters, and alarm thresholds in modular programmable logic controllers. IC Role / Device Role / Timing Role: Persistent configuration store updated infrequently but read on every scan cycle; accessed via deterministic SPI timing. Use Value: Enables field reconfiguration without firmware reload; 1M endurance supports hundreds of commissioning iterations over 10+ years. |
| Medical Device Usage Logs | Energy Meter Firmware Patch Storage |
|
Use Scenario: Recording timestamped operational events (e.g., power cycles, error codes, maintenance alerts) in portable diagnostic equipment. IC Role / Device Role / Timing Role: Circular buffer implemented in EEPROM pages; write operations triggered by critical state transitions. Use Value: 5 ms write time allows logging within 10 ms interrupt latency budgets; 500 nA standby current preserves battery charge between events. |
Use Scenario: Storing signed firmware patches and update metadata in utility-grade electricity meters deployed in remote substations. IC Role / Device Role / Timing Role: Secure boot auxiliary storage holding patch validity flags and version counters; accessed during secure boot verification. Use Value: Hardware write protection (WP + BP bits) prevents tampering with update control flags; 4 kV ESD rating withstands harsh substation EMI. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar SPI EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 25AA640T-I/SN | 1.8–5.5 V supply range; 1 MHz max clock; SOIC-8 package (wider 3.9 mm body vs. TSSOP's 4.4 mm width). | Better suited for mixed-voltage systems (e.g., 1.8 V logic domains); lower speed tolerance reduces timing margin requirements. | Select when board layout accommodates SOIC footprint and system VCC may dip below 2.5 V. |
| 25LC640A-I/SNG | Enhanced revision with improved ESD (6 kV HBM), tighter AC timing specs, and extended qualification per AEC-Q100 Grade 2 for automotive use. | Qualified for under-hood automotive applications; not recommended for new designs unless legacy 25LC640T-I/SNG footprint must be retained. | Prefer for new designs requiring higher reliability; note that 25LC640A-I/SNG is pin-compatible but not identical in marking or traceability. |
Compared with 25LC640T-I/SNG, the 25AA640T-I/SN offers broader voltage flexibility at reduced speed, while the 25LC640A-I/SNG delivers enhanced robustness and automotive qualification - both serve as functional alternatives but require validation of supply, timing, and environmental requirements.
Availability
25LC640T-I/SNG is available at Aetrix Electronics and suitable for industrial control systems, medical instrumentation, smart metering, and embedded sensor modules requiring stable component supply and long-term obsolescence management.
Supply support for 25LC640T-I/SNG 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, and Flash-IP solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.
The 25LC640 series belongs to Microchip's SPI Serial EEPROM product line, designed specifically for cost-sensitive, low-power embedded applications requiring reliable nonvolatile storage with minimal pin count and software overhead.
FAQ
What is the maximum clock frequency supported by the 25LC640T-I/SNG?
The 25LC640T-I/SNG supports a maximum SPI clock frequency of 2 MHz when operated within its specified VCC range of 2.5 V to 5.5 V and industrial temperature range (−40°C to +85°C). At VCC = 4.5–5.5 V, it can operate up to 3 MHz, but this is limited to the automotive-grade variant (25LC640-E/SNG), not the 25LC640T-I/SNG. The 2 MHz rating ensures timing compliance across full voltage and temperature ranges.
Does the 25LC640T-I/SNG support hardware write protection?
Yes, the 25LC640T-I/SNG supports hardware write protection through the WP pin in conjunction with the WPEN bit in the STATUS register. When WPEN = 1 and WP = low, writes to nonvolatile STATUS register bits are disabled. Block-level array protection is controlled separately via BP0/BP1 bits. This dual-layer scheme prevents accidental corruption of critical configuration data during power transients or firmware bugs.
How many write/erase cycles can the 25LC640T-I/SNG endure?
The 25LC640T-I/SNG is rated for 1 million erase/write cycles per memory location, as established by characterization (not 100% tested). This endurance enables frequent updates in applications like usage logging, adaptive calibration, or field-upgradable parameter sets without premature wear-out concerns over typical product lifetimes.
What package type is used for the 25LC640T-I/SNG?
The 25LC640T-I/SNG uses an 8-lead TSSOP package (designated "SNG" per Microchip's part numbering system), with 0.65 mm lead pitch and 4.4 mm body width. It is RoHS-compliant, Pb-free, and optimized for high-density surface-mount assembly using standard reflow profiles.
Is the 25LC640T-I/SNG compatible with SPI Mode 0,0?
Yes, the 25LC640T-I/SNG is fully compatible with SPI Mode 0,0 (CPOL = 0, CPHA = 0): data is sampled on the rising edge of SCK and shifted out on the falling edge. Its SI, SO, SCK, and CS timing specifications align with standard SPI master peripherals found in PIC, STM32, and NXP microcontrollers without requiring custom bit-banging or mode translation.
25LC640T-I/SNG Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Programmable:
- Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- EEPROM
- Technology:
- EEPROM
- Memory Size:
- 64Kbit
- Memory Organization:
- 8K 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:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
25LC640T-I/SNG FAQ
1.How can I place an order for 25LC640T-I/SNG through Aetrix?
Please submit a Request for Quotation (RFQ) for 25LC640T-I/SNG 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 25LC640T-I/SNG reliable?
The price and inventory of 25LC640T-I/SNG are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 25LC640T-I/SNG is usually 5 days.
3.What payment methods are accepted for 25LC640T-I/SNG?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 25LC640T-I/SNG transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 25LC640T-I/SNG?
25LC640T-I/SNG orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 25LC640T-I/SNG 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 25LC640T-I/SNG?
For technical support, including 25LC640T-I/SNG datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 25LC640T-I/SNG requirements.
6.How does Aetrix verify that 25LC640T-I/SNG is sourced from the original manufacturer or authorized distributors?
All 25LC640T-I/SNG 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 25LC640T-I/SNG meets industry standards.
7.What is the process for return or replacement of 25LC640T-I/SNG?
All 25LC640T-I/SNG units undergo pre-shipment inspection (PSI). If there is an issue with 25LC640T-I/SNG, 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 25LC640T-I/SNG part is unused and in its original packaging.
Return procedure for 25LC640T-I/SNG:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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