Part A
25LC640AT-E/SN
微芯片科技
- Lifecycle
- Active
- Stock
- 5205 件
- Series
- 記憶-記憶
Replacement verdict
Compatible functional replacement candidate
The 25LC640AT-E/SN and 25LC640-I/SNG are functionally compatible 64 Kbit SPI serial EEPROM devices offering identical memory density, organization, interface protocol, and supply voltage range. The primary distinction lies in their operating temperature grades and package/ordering specifications, making the 25LC640AT-E/SN a viable functional substitute for the 25LC640-I/SNG in extended-temperature applications, provided that the specific package, tape-and-reel, and qualification requirements of the target design are validated against the intended operating environment.
Memory Density and Organization
High match
Interface Protocol
High match
Supply Voltage Range
High match
Operating Temperature Grade
Validation required
Parts at a glance
Part B
25LC640-I/SNG
微芯片科技
- Lifecycle
- Active
- Stock
- 6707 件
- Package
- SOIC-8
- Series
- 記憶力
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | 25LC640AT-E/SN | 25LC640-I/SNG | Why it matters |
|---|---|---|---|
| Manufacturer Part Number | 25LC640AT-E/SN | 25LC640-I/SNG | Different ordering codes indicate different temperature grades and packaging options, which affects sourcing and application suitability. |
| Temperature Range | -40°C to +125°C (Extended) | -40°C to +85°C (Industrial) | The extended temperature version supports harsher environments such as automotive or industrial applications, while the industrial version is limited to standard industrial conditions. |
| Automotive Qualification | AEC-Q100 qualified | Not AEC-Q100 qualified | AEC-Q100 qualification is required for automotive applications; the non-qualified version cannot be used in automotive designs requiring this standard. |
| Memory Size | 64 Kbit (8K x 8) | 64 Kbit (8K x 8) | Identical memory density ensures the same storage capacity for firmware, calibration data, or configuration parameters. |
| Memory Organization | 8K x 8 | 8K x 8 | Same organization means identical addressing and byte-level access behavior, ensuring software compatibility. |
| Interface Type | SPI (Serial Peripheral Interface) | SPI (Serial Peripheral Interface) | Both use SPI, so the same host controller firmware and pin connections can be reused without modification. |
| Supply Voltage Range | 2.5V to 5.5V | 2.5V to 5.5V | Identical voltage range allows operation from the same power rails in 3.3V or 5V systems. |
| Maximum Clock Frequency | 3 MHz | 3 MHz | Same maximum SPI clock ensures identical read/write throughput and timing compatibility with the host. |
| Package / Mounting | 8-SOIC (Surface Mount) | 8-SOIC (Surface Mount) | Same package and footprint allow drop-in replacement on the same PCB without layout changes. |
| Endurance and Data Retention | 1,000,000 write cycles; >200 years retention | 1,000,000 write cycles; >200 years retention | Equivalent endurance and retention ensure comparable long-term reliability for non-volatile data storage. |
Need help validating a replacement?
Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 25LC640AT-E/SN | 25LC640-I/SNG |
|---|---|---|
| Supplier | - | Microchip Technology |
| Part Status | Active | Obsolete |
| Memory Type | Non-Volatile | Non-Volatile |
| Memory Format | EEPROM | EEPROM |
| Technology | EEPROM | EEPROM |
| Memory Size | 64Kbit | 64Kb (8K x 8) |
| Memory Interface | SPI | SPI |
| Clock Frequency | 10 MHz | 2 MHz |
| Write Cycle Time - Word Page | - | 5ms |
| Voltage - Supply | 2.5V ~ 5.5V | 2.5V ~ 5.5V |
| Operating Temperature | -40°C ~ 125°C (TA) | -40°C ~ 85°C (TA) |
| Mounting Type | Surface Mount | Surface Mount |
| Base Product Number | 25LC640 | - |
| Digi Key Programmable | Verified | - |
| Memory Organization | 8K x 8 | - |
| Write Cycle Time - Word, Page | 5ms | - |
| Packaging | Cut Tape (CT), Tape & Reel (TR) | - |
Frequently asked questions
What are the key differences between the 25LC640AT-E/SN and the 25LC640-I/SNG?
The 25LC640AT-E/SN is an automotive-grade (AEC-Q100 qualified) 64 Kbit SPI serial EEPROM in an 8-lead SOIC package with a temperature range of -40°C to +125°C. The 25LC640-I/SNG is an industrial-grade 64 Kbit SPI serial EEPROM in an 8-lead SOIC package with a temperature range of -40°C to +85°C. The primary differences are the temperature grade, qualification level, and the "G" suffix on the I/SNG indicating a lead-free/RoHS-compliant package.
Are the 25LC640AT-E/SN and 25LC640-I/SNG pin-to-pin compatible?
Yes. Both devices are offered in the standard 8-lead SOIC (SN) package and share the same pinout: CS, SO, WP, VSS, SI, SCK, HOLD, and VCC. They are pin-to-pin compatible when both are in the same 8-lead SOIC package.
Can the 25LC640-I/SNG be used as a drop-in replacement for the 25LC640AT-E/SN?
Not directly in all applications. While both are 64 Kbit SPI EEPROMs with the same pinout and package, the 25LC640AT-E/SN is qualified to AEC-Q100 and rated for operation up to +125°C, whereas the 25LC640-I/SNG is rated only to +85°C. A drop-in replacement is only acceptable if the target application does not require automotive qualification or operation above +85°C.
What is the memory organization and interface of these devices?
Both the 25LC640AT-E/SN and 25LC640-I/SNG are 64 Kbit serial EEPROMs organized as 8192 x 8 bits. They communicate over the SPI bus and support SPI modes 0 and 3, with a maximum clock frequency of 3 MHz at 2.5V and 5 MHz at 4.5V to 5.5V.
What are the operating voltage ranges for the 25LC640AT-E/SN and 25LC640-I/SNG?
Both devices operate from 2.5V to 5.5V. The maximum SPI clock frequency is 3 MHz for VCC from 2.5V to 4.5V and 5 MHz for VCC from 4.5V to 5.5V.
Do both devices support the same operating temperature ranges?
No. The 25LC640AT-E/SN is rated for the extended automotive temperature range of -40°C to +125°C. The 25LC640-I/SNG is rated for the industrial temperature range of -40°C to +85°C. The E suffix indicates the extended temperature grade, while the I suffix indicates the industrial temperature grade.
What does the "G" suffix in 25LC640-I/SNG indicate?
The "G" suffix indicates that the device is packaged in a lead-free (Pb-free) and RoHS-compliant 8-lead SOIC package. The 25LC640AT-E/SN is also available in a lead-free/RoHS-compliant SOIC package, but the ordering code does not include the "G" suffix in the same position.
Are both devices qualified for automotive applications?
Only the 25LC640AT-E/SN is automotive qualified. The "AT" in the ordering code indicates AEC-Q100 qualification and the "E" indicates the extended -40°C to +125°C temperature range. The 25LC640-I/SNG is an industrial-grade device and is not AEC-Q100 qualified.
What are the endurance and data retention specifications for these EEPROMs?
Both the 25LC640AT-E/SN and 25LC640-I/SNG are specified for 1,000,000 erase/write cycles and greater than 200 years of data retention at +25°C, per the manufacturer's datasheet.