Part A
AT24C128C-MAHM-T
Công nghệ Microchip
- Lifecycle
- Active
- Stock
- 7549 PCS
- Package
- UDFN-8
- Series
- Memory
Replacement verdict
Not a drop-in replacement
The AT24C128C-MAHM-T and AT24C08C-MAPD-E are both I²C serial EEPROM devices from the same family, but they differ fundamentally in memory density, package footprint, and operating voltage range. The 128-Kbit device cannot be substituted by the 8-Kbit device without firmware, addressing, and PCB redesign, so this pairing is not a drop-in replacement.
Different memory density
Different package footprint
Different operating voltage
Different page size
Parts at a glance
Part B
AT24C08C-MAPD-E
Công nghệ Microchip
- Lifecycle
- Active
- Stock
- 6982 PCS
- Package
- UFDFN-8
- Series
- Memory
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AT24C128C-MAHM-T | AT24C08C-MAPD-E | Why it matters |
|---|---|---|---|
| Memory Density | 128 Kbit (16,384 x 8) | 8 Kbit (1,024 x 8) | Storage capacity determines how much data can be retained; a 16x difference means these parts are not functionally interchangeable for firmware or log storage. |
| Organization | 16,384 words x 8 bits | 1,024 words x 8 bits | Word count affects address space and the number of address bytes required per transaction, impacting software compatibility. |
| Supply Voltage Range | 1.7 V to 5.5 V | 1.7 V to 5.5 V | Both support the same wide voltage range, allowing operation across common 1.8 V, 3.3 V, and 5 V rails. |
| Maximum Clock Frequency | 1 MHz (Fast Mode Plus) | 1 MHz (Fast Mode Plus) | Bus speed determines throughput; identical 1 MHz support means timing-compatible I2C operation. |
| Interface Type | I2C (2-wire) | I2C (2-wire) | Both use the same 2-wire I2C protocol, so the host controller interface is compatible. |
| Package / Mounting | 8-UDFN (2x3 mm), Surface Mount | 8-TSSOP, Surface Mount | Different package footprints require PCB layout changes; they are not drop-in replacements. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Identical industrial temperature range supports the same environmental conditions. |
| Write Cycle Time (max) | 5 ms | 5 ms | Page write timing affects firmware polling and throughput; identical values simplify software reuse. |
| Endurance | 1,000,000 write cycles | 1,000,000 write cycles | Write endurance determines device lifetime under frequent updates; both offer the same rated endurance. |
| Data Retention | 100 years | 100 years | Retention guarantees long-term non-volatile storage reliability; both are rated equally. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AT24C128C-MAHM-T | AT24C08C-MAPD-E |
|---|---|---|
| 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 | 128Kb (16K x 8) | 8Kb (1K x 8) |
| Memory Interface | I²C | I²C |
| Clock Frequency | 1 MHz | 1 MHz |
| Write Cycle Time - Word Page | 5ms | 5ms |
| Access Time | 550 ns | 900 ns |
| Voltage - Supply | 1.7V ~ 5.5V | 2.5V ~ 5.5V |
| Operating Temperature | -40°C ~ 85°C (TA) | -40°C ~ 125°C (TA) |
| Mounting Type | Surface Mount | Surface Mount |
Frequently asked questions
What are the key differences between the AT24C128C-MAHM-T and AT24C08C-MAPD-E?
The AT24C128C-MAHM-T is a 128-Kbit (16,384 x 8) I²C serial EEPROM, while the AT24C08C-MAPD-E is an 8-Kbit (1,024 x 8) I²C serial EEPROM. The primary differences are memory density, package type, and operating temperature range: the AT24C128C-MAHM-T is supplied in an 8-lead UDFN package rated for -40°C to +85°C, and the AT24C08C-MAPD-E is supplied in an 8-lead UDFN package rated for -40°C to +125°C.
Are the AT24C128C-MAHM-T and AT24C08C-MAPD-E pin-compatible?
Both devices are offered in 8-lead UDFN packages and use the standard I²C EEPROM pinout (A0, A1, A2, GND, SDA, SCL, WP, VCC). However, pin compatibility alone does not guarantee interchangeability; the designer must confirm package dimensions, land pattern, and device addressing against the respective datasheets.
What is the difference in memory organization between these two devices?
The AT24C128C-MAHM-T provides 128 Kbits organized as 16,384 words of 8 bits, requiring a 14-bit data word address. The AT24C08C-MAPD-E provides 8 Kbits organized as 1,024 words of 8 bits, requiring a 10-bit data word address. The larger device therefore needs a two-byte word address during random read/write operations, whereas the smaller device uses a single-byte word address.
Do both devices support the same I²C bus speeds?
Yes. Both the AT24C128C-MAHM-T and AT24C08C-MAPD-E support the I²C Fast Mode (400 kHz) and Standard Mode (100 kHz) interface, consistent with the Atmel/Microchip AT24C series datasheet specifications.
What are the supply voltage requirements for each device?
The AT24C128C-MAHM-T operates from 1.7V to 5.5V, and the AT24C08C-MAPD-E operates from 1.7V to 5.5V, per the respective Microchip datasheets. Both are therefore suitable for low-voltage and 5V systems.
How do the operating temperature ranges compare?
The AT24C128C-MAHM-T is specified for an operating temperature range of -40°C to +85°C. The AT24C08C-MAPD-E is specified for -40°C to +125°C, making it the better choice for higher-temperature environments.
Can the AT24C08C-MAPD-E be used as a drop-in replacement for the AT24C128C-MAHM-T?
No. Although both are I²C EEPROMs in 8-lead UDFN packages, the AT24C08C-MAPD-E has only 8 Kbits of memory versus 128 Kbits for the AT24C128C-MAHM-T, and the device addressing and word address format differ. A drop-in replacement is not possible without firmware and design changes.
What is the write protection feature on these devices?
Both the AT24C128C-MAHM-T and AT24C08C-MAPD-E provide a hardware Write Protect (WP) pin. When WP is tied to VCC, the entire memory array is write-protected; when tied to GND, normal write operations are permitted, per the Microchip AT24C series datasheets.