Part A
25LC640AT-E/SN
Tecnologia Microchip
- Lifecycle
- Active
- Stock
- 5205 PCS
- Series
- Memória - Memória
Replacement verdict
Compatible functional replacement candidate
The 25LC640AT-E/SN and 25LC640A-E/SN16KVAO are functionally compatible 64-Kbit SPI serial EEPROM devices sharing the same memory organization, interface protocol, and supply voltage range. The 25LC640A-E/SN16KVAO carries an automotive-grade qualification that extends its operating temperature range, making it a viable replacement candidate where the extended temperature capability is acceptable or beneficial. Validation is recommended for the temperature range and qualification requirements of the target application.
Memory Organization
High match
Interface Type
High match
Supply Voltage
High match
Operating Temperature Range
Validation required
Parts at a glance
Part B
25LC640A-E/SN16KVAO
Tecnologia Microchip
- Lifecycle
- Active
- Stock
- 2843 PCS
- Package
- SOIC-8
- Series
- Memória
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 | 25LC640A-E/SN16KVAO | Why it matters |
|---|---|---|---|
| Memory Type | EEPROM | EEPROM | Both are serial EEPROM devices, so the fundamental storage technology is the same. |
| Memory Organization | 8K x 8 | 8K x 8 | Identical organization means the same address space and byte-level access behavior. |
| Memory Size | 64 Kbit | 64 Kbit | Equal density ensures the same storage capacity for firmware or configuration data. |
| Interface | SPI | SPI | Both use SPI, so they can connect to the same host controller bus without protocol changes. |
| Clock Frequency | 10 MHz | 10 MHz | Same maximum clock rate supports identical read/write timing budgets. |
| Supply Voltage | 2.5 V to 5.5 V | 2.5 V to 5.5 V | Matching voltage range allows use in the same 3.3 V or 5 V system rails. |
| Operating Temperature | -40°C to +125°C | -40°C to +125°C | Same extended temperature range supports identical automotive and industrial environments. |
| Package / Case | 8-SOIC | 8-SOIC | Identical package footprint enables drop-in board replacement without layout changes. |
| Mounting Type | Surface Mount | Surface Mount | Same mounting style ensures compatibility with the same assembly process. |
| Qualification | AEC-Q100 | AEC-Q100 | Both are automotive-qualified, so they meet the same reliability and quality standards. |
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 | 25LC640A-E/SN16KVAO |
|---|---|---|
| Supplier | - | Microchip Technology |
| Series | - | Automotive, AEC-Q100 |
| Part Status | Active | Active |
| 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 | 10 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 ~ 125°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 25LC640AT-E/SN and 25LC640A-E/SN16KVAO devices?
Both are Microchip Technology 64 Kbit SPI serial EEPROM devices in the 25LC640A family. The 25LC640AT-E/SN is supplied in an 8-lead SOIC package and is specified for the industrial temperature range of -40°C to +125°C. The 25LC640A-E/SN16KVAO is the same 25LC640A die in the same 8-lead SOIC package and industrial temperature range, but is processed and qualified as an automotive-grade device under Microchip's VAO (Automotive) designation.
What is the memory organization and interface of these devices?
Each device provides 64 Kbit (8,192 x 8) of serial EEPROM organized as 8,192 bytes. They communicate over a standard SPI bus supporting SPI modes 0,0 and 1,1, with a maximum clock frequency of 10 MHz at 5.0 V and 5 MHz at 2.5 V. The devices support byte write, page write (up to 32 bytes), and sequential read operations.
What supply voltage range do the 25LC640AT-E/SN and 25LC640A-E/SN16KVAO support?
Both devices operate from 2.5 V to 5.5 V, making them suitable for 3.3 V and 5.0 V systems. Current consumption is typically 5 mA during read at 5.5 V and 3 mA during write at 5.5 V, with standby current typically 1 µA at 5.5 V.
What is the difference between the 25LC640AT-E/SN and the 25LC640A-E/SN16KVAO?
The primary difference is qualification level. The 25LC640AT-E/SN is a standard industrial-grade device. The 25LC640A-E/SN16KVAO is an automotive-qualified variant carrying Microchip's VAO designation, meaning it is manufactured and tested to automotive quality and reliability standards, including AEC-Q100 qualification. The "16KVAO" suffix in the ordering code identifies the automotive VAO qualification. Electrical parameters and package footprint are otherwise equivalent.
Are the 25LC640AT-E/SN and 25LC640A-E/SN16KVAO pin-compatible?
Yes. Both devices use the standard 8-lead SOIC pinout for the 25LC640A family: pin 1 CS, pin 2 SO, pin 3 WP, pin 4 VSS, pin 5 SI, pin 6 SCK, pin 7 HOLD, pin 8 VCC. Because the package, pinout, and die are the same, they are pin-to-pin compatible in the same PCB land pattern.
Can the 25LC640AT-E/SN be substituted with the 25LC640A-E/SN16KVAO in an existing design?
In most cases yes, because both share the same die, package, pinout, supply range, and SPI interface. However, substitution should be validated against the target application requirements. The VAO variant is intended for automotive applications and may carry different documentation, traceability, and qualification requirements. Designers should confirm that the automotive qualification level and any associated documentation are acceptable for the end application.
What are the operating temperature ranges for these devices?
Both the 25LC640AT-E/SN and the 25LC640A-E/SN16KVAO are specified for the industrial temperature range of -40°C to +125°C. The "E" in the ordering code denotes this extended industrial temperature range.
What package and ordering information should be considered when selecting between these parts?
Both devices are offered in the 8-lead SOIC (150 mil) package, denoted by the "SN" suffix. The 25LC640AT-E/SN uses the standard industrial ordering code, while the 25LC640A-E/SN16KVAO uses the automotive VAO ordering code with the "16KVAO" suffix. When ordering, confirm the correct part number for the required qualification level, as the two are not interchangeable in ordering systems even though they are functionally and physically compatible.