Part A
25LC1024T-E/SM
Mikrochip-Technologie
- Lifecycle
- Active
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- 6964 Stückzahl
- Package
- SOIC-8
- Series
- Speicher
Replacement verdict
Not a drop-in replacement
The 25LC1024T-E/SM and 25LC128-E/SN16KVAO are not functionally interchangeable. The 25LC1024T-E/SM provides 1 Mbit of SPI serial EEPROM in an 8-lead SOIC package, while the 25LC128-E/SN16KVAO offers only 128 Kbit in a 16-lead SOIC package. The eightfold density difference, mismatched pin count and footprint, divergent operating voltage ranges, and differing automotive qualification status make direct substitution infeasible without circuit redesign and firmware adaptation.
Different memory density
Different package footprint
Different supply voltage range
Different qualification grade
Parts at a glance
Part B
25LC128-E/SN16KVAO
Mikrochip-Technologie
- Lifecycle
- Active
- Stock
- 7092 Stückzahl
- Package
- SOIC-8
- Series
- Speicher
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-E/SN16KVAO | Why it matters |
|---|---|---|---|
| Memory Density | 1 Mbit (128K x 8) | 128 Kbit (16K x 8) | Density determines total storage capacity; the 25LC1024 offers eight times the storage of the 25LC128, so they are not drop-in substitutes for firmware or data-logging applications. |
| Organization | 128K x 8 | 16K x 8 | Byte organization affects address width and page addressing; different word counts require different address byte handling in firmware. |
| Page Size | 256 bytes | 64 bytes | Page size limits the maximum bytes per write cycle; mismatched page sizes can cause data wrap-around if firmware assumes the wrong boundary. |
| Maximum Clock Frequency | 10 MHz | 10 MHz | Clock rate determines SPI throughput; both support 10 MHz, so bus timing compatibility is maintained. |
| Supply Voltage Range | 2.5 V to 5.5 V | 2.5 V to 5.5 V | Operating voltage 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 | -40 °C to +125 °C | Temperature grade determines suitability for automotive and industrial environments; both meet the extended range. |
| Package / Mounting | 8-SOIC (SOIJ), Surface Mount | 8-SOIC, Surface Mount | Footprint and lead pitch must match the PCB land pattern; both are 8-pin SOIC but body width variants may affect assembly. |
| Write Cycle Time (max) | 5 ms | 5 ms | Write cycle time affects update latency and polling requirements; identical values simplify firmware timing. |
| Endurance | 1,000,000 write cycles | 1,000,000 write cycles | Endurance defines how many times each byte can be rewritten; matching endurance supports equivalent product lifetime. |
| Data Retention | >200 years | >200 years | Retention guarantees non-volatile storage life; equivalent retention means no difference for long-life applications. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 25LC1024T-E/SM | 25LC128-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 | 1Mb (128K x 8) | 128Kb (16K x 8) |
| Memory Interface | SPI | SPI |
| Clock Frequency | 20 MHz | 5 MHz |
| Write Cycle Time - Word Page | 6ms | 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 |
Frequently asked questions
What are the key differences between the 25LC1024T-E/SM and the 25LC128-E/SN16KVAO?
The 25LC1024T-E/SM is a 1 Mbit SPI serial EEPROM in an 8-lead SOIC package, while the 25LC128-E/SN16KVAO is a 128 Kbit SPI serial EEPROM in an 8-lead SOIC package. The primary differences are memory density (1 Mbit vs. 128 Kbit), page size, and operating temperature range. The 25LC1024T-E/SM is rated for -40°C to +125°C, and the 25LC128-E/SN16KVAO is rated for -40°C to +125°C as an automotive-qualified device.
Are the 25LC1024T-E/SM and 25LC128-E/SN16KVAO pin-compatible?
Yes, both devices use the standard 8-lead SOIC pinout for Microchip SPI serial EEPROMs: CS, SO, WP, VSS, SI, SCK, HOLD, and VCC. However, pin compatibility alone does not guarantee functional equivalence; firmware and timing parameters must be validated.
Can the 25LC128-E/SN16KVAO be used as a direct drop-in replacement for the 25LC1024T-E/SM?
No. The 25LC128-E/SN16KVAO has only 128 Kbit of memory versus 1 Mbit in the 25LC1024T-E/SM. A direct drop-in replacement is not possible if the application requires the full 1 Mbit density or relies on the 25LC1024's specific page size and instruction set. Firmware must be reviewed for addressing and page boundary differences.
What are the operating voltage ranges for these two EEPROMs?
Both the 25LC1024T-E/SM and the 25LC128-E/SN16KVAO operate from 2.5V to 5.5V. This wide voltage range supports both 3.3V and 5V system designs.
What is the page size for each device?
The 25LC1024T-E/SM has a 256-byte page size. The 25LC128-E/SN16KVAO has a 64-byte page size. This difference affects write cycle timing and firmware page-write routines.
What are the maximum clock frequencies for the 25LC1024T-E/SM and 25LC128-E/SN16KVAO?
The 25LC1024T-E/SM supports a maximum SPI clock frequency of 20 MHz. The 25LC128-E/SN16KVAO supports a maximum SPI clock frequency of 10 MHz. System designers must ensure the SPI master does not exceed these limits.
Are both devices qualified for automotive applications?
The 25LC128-E/SN16KVAO is an automotive-qualified device, as indicated by its VAO suffix and AEC-Q100 qualification. The 25LC1024T-E/SM is an industrial-grade device rated for -40°C to +125°C but is not specifically automotive-qualified. Designers should verify qualification requirements for their target application.
What are the endurance and data retention specifications for these EEPROMs?
Both the 25LC1024T-E/SM and the 25LC128-E/SN16KVAO are specified for 1,000,000 erase/write cycles and greater than 200 years of data retention at 25°C, per Microchip's datasheet parameters for these device families.