Part A
AT24C128C-MAHM-T
Technologie de micropuce
- Lifecycle
- Active
- Stock
- 7549 PCS
- Package
- UDFN-8
- Series
- Mémoire
Replacement verdict
Compatible functional replacement candidate
The AT24C04C-MAPD-E is not a direct drop-in replacement for the AT24C128C-MAHM-T due to a significant difference in memory density and package footprint, but it can serve as a functional substitute in applications where the reduced 4 Kbit capacity is acceptable and the board layout is redesigned for the smaller package. Designers must verify memory requirements and update the PCB footprint before adopting this substitution.
Memory Density
Not compatible
Package Type
Not compatible
Supply Voltage Range
High match
Interface Type
High match
Parts at a glance
Part B
AT24C04C-MAPD-E
Technologie de micropuce
- Lifecycle
- Active
- Stock
- 8884 PCS
- Package
- UFDFN-8
- Series
- Mémoire
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 | AT24C04C-MAPD-E | Why it matters |
|---|---|---|---|
| Memory Density | 128 Kbit (16,384 x 8) | 4 Kbit (512 x 8) | Determines total storage capacity; a 128 Kbit device holds 32x more data than a 4 Kbit device, so they are not functionally interchangeable for capacity-bound designs. |
| Memory Organization | 16,384 words x 8 bits | 512 words x 8 bits | Defines the addressable word count and thus the address width required by the host; firmware addressing must match the device organization. |
| Supply Voltage Range | 1.7 V to 5.5 V | 1.7 V to 5.5 V | Both support the same wide 1.7–5.5 V range, allowing operation from common 1.8 V, 3.3 V, and 5 V rails. |
| Maximum Clock Frequency | 1 MHz (5 V), 400 kHz (1.7 V) | 1 MHz (5 V), 400 kHz (1.7 V) | Sets the I2C bus speed; matching fast-mode/fast-mode-plus support ensures timing compatibility with the host controller. |
| Package / Mounting | 8-UFDFN (2x3 mm), Surface Mount | 8-UDFN (2x3 mm), Surface Mount | Footprint and mounting must match the PCB layout; both use the same small UDFN package family, aiding drop-in placement. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Confirms both parts are rated for industrial temperature environments, suitable for the same application conditions. |
| Interface Type | I2C (2-wire), up to 1 MHz | I2C (2-wire), up to 1 MHz | Both use the standard I2C serial interface, so the same bus protocol and host driver architecture apply. |
| Write Cycle Time | 5 ms max (page/byte write) | 5 ms max (page/byte write) | Determines how quickly the device completes internal write operations; identical timing simplifies firmware polling and throughput planning. |
| Page Size | 64 bytes | 16 bytes | Page write buffer size affects burst-write efficiency and firmware page-boundary handling; the 128 Kbit part allows larger page writes. |
| Data Retention | 100 years | 100 years | Indicates long-term non-volatile storage reliability; both meet the same retention specification for persistent data. |
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 | AT24C128C-MAHM-T | AT24C04C-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) | 4Kb (512 x 8) |
| Memory Interface | I²C | I²C |
| Clock Frequency | 1 MHz | 400 kHz |
| 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 AT24C04C-MAPD-E?
The AT24C128C-MAHM-T is a 128-Kbit (16,384 x 8) I²C serial EEPROM, while the AT24C04C-MAPD-E is a 4-Kbit (512 x 8) device. They differ in memory density, I²C slave address configuration, page size, and package type, so they are not drop-in replacements for each other.
What are the memory organization and page sizes of these two EEPROMs?
The AT24C128C-MAHM-T is organized as 16,384 bytes with a 64-byte page write buffer. The AT24C04C-MAPD-E is organized as 512 bytes with a 16-byte page write buffer. Page size affects write cycle timing and firmware buffering strategy.
What I²C slave addressing differences should designers consider?
The AT24C128C uses a 2-wire I²C address with the upper address bits fixed and lower bits configurable via A1/A0 pins, supporting up to four devices on the bus. The AT24C04C uses a different address scheme where the memory block select bit is embedded in the slave address, so the number of addressable devices and address byte format differ between the two parts.
What supply voltage ranges do these devices support?
Both the AT24C128C-MAHM-T and AT24C04C-MAPD-E are specified for a 1.7 V to 5.5 V supply range, allowing operation from common 1.8 V, 2.5 V, 3.3 V, and 5 V rails. Always confirm the exact datasheet revision for the specific ordering code before finalizing a design.
What package types are used for these two ordering codes?
The AT24C128C-MAHM-T is supplied in an 8-lead UDFN package, while the AT24C04C-MAPD-E is supplied in an 8-lead TSSOP package. Because the package footprints and land patterns differ, PCB layout changes are required when switching between them.
What are the maximum I²C clock frequencies for these EEPROMs?
Both devices support Fast Mode operation at up to 400 kHz and Standard Mode at 100 kHz. The AT24C128C additionally supports Fast Mode Plus at 1 MHz for certain supply voltage conditions per its datasheet. Verify the specific timing table for the exact ordering code before operating at the highest bus speed.
What are the operating temperature ranges for these parts?
The AT24C128C-MAHM-T is specified for the industrial temperature range of -40 °C to +85 °C. The AT24C04C-MAPD-E is specified for the industrial temperature range of -40 °C to +85 °C as well. Confirm the suffix-specific rating in the manufacturer datasheet for each ordering code.
Can the AT24C04C-MAPD-E be used as a direct replacement for the AT24C128C-MAHM-T?
No. The AT24C04C-MAPD-E has only 4 Kbit of memory versus 128 Kbit for the AT24C128C-MAHM-T, uses a different I²C addressing scheme, has a smaller page size, and is housed in a different package. A direct substitution would require firmware and PCB changes and would not provide equivalent storage capacity.