Part A
25LC128-I/SN
마이크로칩 기술
- Lifecycle
- Active
- Stock
- 1836 PCS
- Series
- 기억. - 기억.
Replacement verdict
Not a drop-in replacement
The 25LC1024T-E/SM and 25LC128-I/SN are not functionally interchangeable. The 25LC1024T-E/SM offers 1 Mbit of EEPROM density in an SOIC-8 package with an extended temperature range, while the 25LC128-I/SN provides only 128 Kbit in the same SOIC-8 package with an industrial temperature range. The eightfold difference in memory density, divergent maximum clock frequencies, and mismatched operating temperature grades make direct substitution impractical without a complete system redesign.
Different memory density
Different clock frequency
Different temperature grade
Different page size
Parts at a glance
Part B
25LC1024T-E/SM
마이크로칩 기술
- Lifecycle
- Active
- Stock
- 6964 PCS
- Package
- SOIC-8
- Series
- 기억력
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | 25LC1024T-E/SM | 25LC128-I/SN | Why it matters |
|---|---|---|---|
| Memory Density | 1 Mbit (128K x 8) | 128 Kbit (16K x 8) | Storage capacity differs by 8x; the two parts are not drop-in substitutes for applications requiring a specific memory size. |
| Organization | 128K x 8 | 16K x 8 | Byte-per-page addressing and total addressable range differ, affecting firmware addressing and page boundary handling. |
| Page Size | 256 bytes | 64 bytes | Page buffer size determines maximum bytes per write cycle; firmware page-write routines must match the device page size. |
| Maximum Clock Frequency | 10 MHz | 10 MHz | SPI bus speed affects throughput; both support 10 MHz, so timing compatibility is maintained. |
| Supply Voltage Range | 2.5 V to 5.5 V | 2.5 V to 5.5 V | Operating voltage window must match the host system rail; identical ranges allow use in the same 3.3 V or 5 V designs. |
| Operating Temperature Range | -40 °C to +125 °C (Extended) | -40 °C to +85 °C (Industrial) | The extended-temperature part supports harsher environments; the industrial part is limited to 85 °C, restricting automotive or high-temp use. |
| Package / Mounting | 8-SOIC (SOIJ), Surface Mount | 8-SOIC (SOIC), Surface Mount | Footprint and lead pitch must match the PCB land pattern; both are 8-pin SOIC but body width variants may affect layout. |
| Interface Type | SPI (Serial Peripheral Interface) | SPI (Serial Peripheral Interface) | Protocol compatibility ensures the same host controller can communicate with either device without firmware changes. |
| Write Cycle Time (Max) | 5 ms | 5 ms | Internal write cycle timing affects polling and data-logging latency; identical values preserve timing behavior. |
| Endurance | 1,000,000 write cycles | 1,000,000 write cycles | Erase/write endurance determines product lifetime in high-write applications; equal endurance means comparable reliability. |
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 | 25LC128-I/SN | 25LC1024T-E/SM |
|---|---|---|
| Part Status | Active | Active |
| Base Product Number | 25LC128 | - |
| Digi Key Programmable | Verified | - |
| Memory Type | Non-Volatile | Non-Volatile |
| Memory Format | EEPROM | EEPROM |
| Technology | EEPROM | EEPROM |
| Memory Size | 128Kbit | 1Mb (128K x 8) |
| Memory Organization | 16K x 8 | - |
| Memory Interface | SPI | SPI |
| Clock Frequency | 10 MHz | 20 MHz |
| Write Cycle Time - Word, Page | 5ms | - |
| Voltage - Supply | 2.5V ~ 5.5V | 2.5V ~ 5.5V |
| Operating Temperature | -40°C ~ 85°C (TA) | -40°C ~ 125°C (TA) |
| Mounting Type | Surface Mount | Surface Mount |
| Packaging | Tube | - |
| Write Cycle Time - Word Page | - | 6ms |
Frequently asked questions
What are the key differences between the 25LC1024T-E/SM and the 25LC128-I/SN?
The 25LC1024T-E/SM is a 1 Mbit SPI serial EEPROM in an 8-lead SOIJ package with an extended temperature range of -40°C to +125°C, while the 25LC128-I/SN is a 128 Kbit SPI serial EEPROM in an 8-lead SOIC package with an industrial temperature range of -40°C to +85°C. The primary differences are memory density, package type, and temperature grade.
Are the 25LC1024T-E/SM and 25LC128-I/SN pin-to-pin compatible?
Both devices use an 8-lead package with the same standard SPI pinout (CS, SO, WP, VSS, SI, SCK, HOLD, VCC). However, the 25LC1024T-E/SM uses the SOIJ (EIAJ SOIC) package while the 25LC128-I/SN uses the standard SOIC (SN) package. These packages have different body widths and PCB land patterns, so they are not drop-in replacements without verifying footprint compatibility.
Can the 25LC128-I/SN be substituted with the 25LC1024T-E/SM in an existing design?
Substitution requires validation of several factors: the 25LC1024T-E/SM offers 1 Mbit versus 128 Kbit, so firmware addressing and page size handling must be updated. The SOIJ package footprint differs from the SOIC footprint, and the extended temperature grade of the 25LC1024T-E/SM exceeds the industrial grade of the 25LC128-I/SN. Direct substitution is not recommended without confirming these parameters against the respective datasheets.
What are the operating voltage ranges for these two EEPROM devices?
Both the 25LC1024T-E/SM and the 25LC128-I/SN operate over a supply voltage range of 2.5V to 5.5V, supporting typical 3.3V and 5V system designs. Designers should verify the specific datasheet for any derating or timing considerations at the voltage extremes.
What SPI clock frequencies do the 25LC1024T-E/SM and 25LC128-I/SN support?
The 25LC1024T-E/SM supports SPI clock frequencies up to 20 MHz, while the 25LC128-I/SN supports up to 10 MHz. The higher clock rate of the 25LC1024T-E/SM allows faster data throughput, which may be advantageous in applications requiring rapid configuration or data logging.
Do these devices support page write and sector erase operations?
Yes, both devices support page write operations. The 25LC1024T-E/SM has a 256-byte page size, and the 25LC128-I/SN has a 64-byte page size. Both also support byte write and full array erase. The difference in page size affects write cycle timing and firmware buffering requirements.
What are the endurance and data retention specifications for these EEPROMs?
Both the 25LC1024T-E/SM and the 25LC128-I/SN are specified for a minimum of 1,000,000 erase/write cycles and data retention greater than 200 years, as stated in the Microchip datasheets. These ratings are typical for high-reliability serial EEPROM products.
Which device is better suited for high-temperature industrial applications?
The 25LC1024T-E/SM is rated for an extended temperature range of -40°C to +125°C, making it suitable for harsh environments such as automotive or industrial control systems. The 25LC128-I/SN is rated for -40°C to +85°C, which is adequate for standard industrial applications but not for extreme high-temperature conditions.