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Microchip Technology 25LC640AT-I/MNY
- Part No.:
- 25LC640AT-I/MNY
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-WFDFN Exposed Pad
- Datasheet:
-
25LC640AT-I/MNY.pdf
- Description:
- IC EEPROM 64KBIT SPI 10MHZ 8TDFN
- Quantity:
- Payment:
- Shipping:
Inventory:19,518
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Product details
Overview
25LC640AT-I/MNY from Microchip Technology Inc. is a 64-Kbit SPI Serial EEPROM with 8192 × 8-bit organization, 32-byte page size, and 10 MHz max clock (at VCC ≥ 4.5V). It features hardware write protection via WP pin, HOLD function for interrupt-safe pausing, and AEC-Q100 qualification for automotive applications.
For engineers reviewing the 25LC640AT-I/MNY datasheet, 25LC640AT-I/MNY pinout, 25LC640AT-I/MNY application, or 25LC640AT-I/MNY equivalent, this device supports reliable nonvolatile data storage in microcontroller-based systems requiring industrial-temperature operation (–40°C to +85°C), low-power standby (1 µA), and robust write endurance (1 million cycles).
Technical Context
The 25LC640AT-I/MNY implements a standard SPI Mode 0,0/Multi-Mode 1,1 interface with separate SI (data-in) and SO (data-out) lines, controlled by CS, SCK, and optional HOLD/WP signals. Its internal architecture includes a 32-byte page latch, status register with BP0/BP1 block protection bits, and HV generator for EEPROM programming.
It operates across 2.5V–5.5V supply, with voltage-dependent AC timing: 10 MHz max at 4.5–5.5V, 5 MHz at 2.5–4.5V, and 3 MHz below 2.5V. Internal write cycle time is fixed at ≤5 ms, independent of voltage or temperature within rated range.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 64 Kbit (8192 × 8-bit), enabling storage of firmware parameters, calibration data, or configuration settings in space-constrained designs. |
| Interface | SPI-compatible serial bus (Mode 0,0 / Mode 1,1), allowing direct connection to PIC® and other MCU SPI peripherals without glue logic. |
| Page Size | 32 bytes - defines maximum contiguous write length per command; crossing page boundaries wraps data within same physical page. |
| Write Endurance | 1,000,000 erase/write cycles - supports frequent logging or dynamic parameter updates over product lifetime. |
| Data Retention | >200 years at +85°C - ensures long-term integrity of stored calibration, serial numbers, or security keys without refresh. |
| Supply Voltage | 2.5V to 5.5V - compatible with both 3.3V and 5V system rails, eliminating need for level shifters in mixed-voltage designs. |
| Operating Temp | –40°C to +85°C (Industrial grade) - validated for use in automotive ECUs, industrial controllers, and outdoor equipment. |
Pinout & Package
25LC640AT-I/MNY is packaged in an 8-lead MSOP (150 mil), marked "5LCAT" on top, with exposed pad connected to VSS or left floating. Pin numbering follows standard MSOP orientation (pin 1 = CS, pin 8 = VCC).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS (Pin 1) | Chip Select Input | Active-low enable: asserts SPI communication; rising edge after WRITE initiates internal 5 ms write cycle. |
| SO (Pin 2) | Serial Data Output | Tri-state output driven on falling SCK edge; high-impedance when CS high or HOLD low. |
| WP (Pin 3) | Write-Protect Control | Hardware lock: disables STATUS register writes when WPEN=1 and WP=low; otherwise ignored. |
| VSS (Pin 4) | Ground Reference | Return path for all I/O and core logic; must be low-impedance to ensure noise immunity during read/write. |
| SI (Pin 5) | Serial Data Input | Latches instruction/address/data on rising SCK edge; requires setup/hold timing per VCC (e.g., 10 ns at 5V). |
| SCK (Pin 6) | Serial Clock Input | Synchronizes all SPI transfers; max frequency scales with VCC (10 MHz @ 5.5V, 3 MHz @ 1.8V). |
| HOLD (Pin 7) | Communication Pause | Halts ongoing SPI sequence without reset; must be asserted while SCK is low to avoid bus contention. |
| VCC (Pin 8) | Power Supply | 2.5–5.5V operating range; decoupling capacitor (0.1 µF) required near pin to suppress switching noise. |
Key Features
| Feature | Design Value |
|---|---|
| Block Write Protection | Selectable via STATUS register (BP1/BP0): protect none, upper 1/4 (1800h–1FFFh), upper 1/2 (1000h–1FFFh), or full array (0000h–1FFFh). |
| Self-Timed Write Cycle | Fixed ≤5 ms internal erase/write - eliminates need for external timeout logic or polling delay in host firmware. |
| Power-On Write Protection | Write enable latch resets at power-up; WREN instruction required before any write - prevents accidental writes during brownout. |
| HOLD Function | Pauses active SPI transfer mid-sequence; resumes from exact byte/bit position upon HOLD release - enables deterministic interrupt handling. |
| AEC-Q100 Qualification | Qualified for automotive applications (Grade 3: –40°C to +85°C); includes stress testing for reliability in engine control, body electronics, and ADAS modules. |
Applications
| Automotive Engine Control Unit (ECU) | Industrial PLC Configuration Storage |
|---|---|
Use Scenario: Storing fuel map coefficients, sensor calibration offsets, and fault code history in engine management systems. IC Role / Device Role / Timing Role: Nonvolatile parameter memory interfaced directly to PIC® MCU SPI port; accessed during boot and runtime via sequential READ/WRITE. Use Value: AEC-Q100 qualification ensures operation across thermal cycling and vibration; 1M endurance supports recalibration over 10+ years of service life. |
Use Scenario: Retaining I/O mapping, ladder logic parameters, and user-defined alarm thresholds in programmable logic controllers. IC Role / Device Role / Timing Role: SPI-configurable EEPROM used for field-updatable configuration; accessed during startup and maintenance mode. Use Value: Block protection (BP1/BP0) isolates critical firmware settings from accidental overwrite during routine parameter edits. |
| Medical Infusion Pump Calibration | Smart Meter Firmware Patch Storage |
Use Scenario: Holding flow-rate calibration constants, motor step compensation tables, and safety-critical limits in battery-powered infusion devices. IC Role / Device Role / Timing Role: Low-power (1 µA standby) nonvolatile memory storing FDA-mandated traceability data and calibration history. Use Value: >200-year data retention guarantees integrity of calibration records throughout device lifecycle, satisfying regulatory audit requirements. |
Use Scenario: Storing encrypted firmware patches and cryptographic keys for secure over-the-air (OTA) updates in utility smart meters. IC Role / Device Role / Timing Role: Secure configuration store accessed only during authenticated OTA update sequences; WP pin hardwired to prevent runtime tampering. Use Value: Hardware write protection (WP + WPEN) blocks unauthorized modification of patch metadata, enforcing chain-of-trust during field updates. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 25AA640AT-I/MNY | Wider VCC range (1.8–5.5V); supports 3.3V/1.8V systems where 25LC640AT-I/MNY cannot operate. | Preferred for battery-powered IoT sensors or ultra-low-voltage MCUs requiring <2.5V operation. | Select when supply voltage may dip below 2.5V; verify timing margins at lower VCC. |
| AT25DF641-MAU-T | Dual/quad SPI interface; 64 Mbit density; no HOLD pin; different command set and status register layout. | Used in high-speed firmware storage (e.g., boot code), not parameter/configuration storage. | Not drop-in; requires firmware rework for SPI protocol and address mapping; choose only for bandwidth-sensitive applications. |
Compared with 25AA640AT-I/MNY and AT25DF641-MAU-T, the 25LC640AT-I/MNY offers optimal balance of industrial temperature support, hardware write protection, and SPI simplicity for configuration storage - avoiding unnecessary complexity or voltage incompatibility.
Availability
25LC640AT-I/MNY is available at Aetrix Electronics and suitable for automotive ECU development, industrial PLC configuration, and medical device calibration requiring stable component supply across extended production lifecycles.
Supply support for 25LC640AT-I/MNY 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 25LC640A family was designed specifically for robust, low-power, SPI-based nonvolatile storage in automotive and industrial control systems - emphasizing AEC-Q100 compliance, write endurance, and hardware-level data protection.
FAQ
What is the maximum clock frequency supported by the 25LC640AT-I/MNY?
The 25LC640AT-I/MNY supports up to 10 MHz SPI clock frequency when VCC is between 4.5V and 5.5V. At 2.5V ≤ VCC < 4.5V, max frequency drops to 5 MHz; below 2.5V, it is limited to 3 MHz. These voltage-dependent timing constraints are defined in Table 1-2 of the DS20001830G datasheet and must be observed to ensure reliable communication with the 25LC640AT-I/MNY.
Does the 25LC640AT-I/MNY require external pull-up resistors on its SPI lines?
The 25LC640AT-I/MNY does not require external pull-ups on SI, SCK, or CS - these inputs have CMOS-compatible thresholds and are actively driven by the host MCU. However, SO is open-drain capable and may benefit from a weak pull-up (e.g., 10 kΩ) in multi-drop SPI buses to ensure clean signal transitions; the 25LC640AT-I/MNY itself does not mandate it for single-device operation.
How does the HOLD function work on the 25LC640AT-I/MNY during an active SPI transaction?
When HOLD is pulled low while SCK is low, the 25LC640AT-I/MNY immediately pauses the current SPI sequence - SI, SCK, and SO enter high-impedance states, and all input transitions are ignored except CS. Communication resumes from the exact bit position when HOLD is raised while SCK remains low. This behavior allows the host MCU to service higher-priority interrupts without losing SPI state in the 25LC640AT-I/MNY.
Can the 25LC640AT-I/MNY be used in a 1.8V system?
No - the 25LC640AT-I/MNY has a minimum VCC rating of 2.5V, as specified in the Device Selection Table and Electrical Characteristics. For 1.8V operation, the pin-compatible 25AA640AT-I/MNY (1.8–5.5V range) is the appropriate alternative. Using the 25LC640AT-I/MNY below 2.5V violates absolute maximum ratings and risks unreliable operation or data corruption.
What happens to the write enable latch after a successful write operation on the 25LC640AT-I/MNY?
After a successful WRITE, WRSR, or WRDI instruction, the write enable latch in the 25LC640AT-I/MNY is automatically reset. This means the next write attempt will fail unless WREN is reissued first. Power-up also resets the latch. This safety mechanism prevents unintended writes and is enforced in hardware - no software polling of the WEL bit is needed to confirm latch state after each operation involving the 25LC640AT-I/MNY.
25LC640AT-I/MNY Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-WFDFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- EEPROM
- Technology:
- EEPROM
- Memory Size:
- 64Kbit
- Memory Organization:
- 8K 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 ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-TDFN (2x3)
25LC640AT-I/MNY FAQ
1.How can I place an order for 25LC640AT-I/MNY through Aetrix?
Please submit a Request for Quotation (RFQ) for 25LC640AT-I/MNY 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 25LC640AT-I/MNY reliable?
The price and inventory of 25LC640AT-I/MNY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 25LC640AT-I/MNY is usually 5 days.
3.What payment methods are accepted for 25LC640AT-I/MNY?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 25LC640AT-I/MNY transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 25LC640AT-I/MNY?
25LC640AT-I/MNY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 25LC640AT-I/MNY 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 25LC640AT-I/MNY?
For technical support, including 25LC640AT-I/MNY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 25LC640AT-I/MNY requirements.
6.How does Aetrix verify that 25LC640AT-I/MNY is sourced from the original manufacturer or authorized distributors?
All 25LC640AT-I/MNY 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 25LC640AT-I/MNY meets industry standards.
7.What is the process for return or replacement of 25LC640AT-I/MNY?
All 25LC640AT-I/MNY units undergo pre-shipment inspection (PSI). If there is an issue with 25LC640AT-I/MNY, 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 25LC640AT-I/MNY part is unused and in its original packaging.
Return procedure for 25LC640AT-I/MNY:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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