Microchip Technology AT24C128-10PU-2.7

Overview

AT24C128-10PU-2.7 from Microchip Technology (formerly Atmel) is a 128 Kbit (16,384 × 8) two-wire serial EEPROM optimized for low-voltage industrial applications. It operates from 2.7V to 5.5V, supports 400 kHz I²C bus speed at 2.7V, features hardware write protection via the WP pin, and delivers 1 million write cycles with 40-year data retention. It is commonly used in embedded system configuration storage, sensor calibration data logging, and power meter firmware parameter backup.

For engineers reviewing the AT24C128-10PU-2.7 datasheet, AT24C128-10PU-2.7 pinout, AT24C128-10PU-2.7 application, or AT24C128-10PU-2.7 equivalent, key selection considerations include its 8-lead PDIP package, 2.7–5.5 V supply range, 400 kHz I²C timing at 2.7V, 64-byte page write capability, and hardware write protect functionality - all critical for legacy industrial control and metering designs requiring long-term nonvolatile memory stability.

Technical Context

The AT24C128-10PU-2.7 implements a standard two-wire (I²C-compatible) serial interface with open-drain SDA and edge-triggered SCL, supporting cascaded addressing via A0/A1 pins for up to four devices on one bus. Its internal architecture organizes memory as 256 pages of 64 bytes each, enabling partial-page writes and automatic address incrementing during sequential reads.

It uses Schmitt-trigger inputs with noise filtering on SCL/SDA, supports acknowledge polling during write cycles, and enters low-power standby mode after STOP condition or power-up. The device complies with I²C protocol timing requirements including tLOW ≥1.3 µs and tHIGH ≥0.6 µs at 2.7V, and guarantees 1 million endurance cycles when bearing the "B" process mark (not applicable to this -10PU-2.7 variant per datasheet note).

Key Specifications

Pinout & Package

AT24C128-10PU-2.7 is supplied in an 8-lead JEDEC PDIP (Plastic Dual Inline Package), 0.300" wide body, RoHS-compliant and halogen-free ("U" suffix). Pin 1 is bottom-left corner when viewing top side with notch or dot orientation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar serial EEPROM applications.

Compared with AT24C128-10PU-2.7, the AT24C128B-10PU-2.7 provides higher endurance and extended temperature range for future-proofing, while the M24C128-WMN6TP offers automotive qualification and SO8 packaging - both require layout or qualification review but serve overlapping configuration-storage roles.

Availability

AT24C128-10PU-2.7 is available at Aetrix Electronics and suitable for industrial power metering, legacy PLC upgrades, and medical calibration data storage requiring stable component supply and long-lifecycle support.

Supply support for AT24C128-10PU-2.7 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Microchip Technology acquired Atmel in 2016 and maintains full support for the AT24Cxx EEPROM family, emphasizing reliability, longevity, and industrial-grade qualification.

The AT24C128 product line was designed for cost-sensitive, low-power embedded systems needing trusted nonvolatile storage - especially where through-hole assembly, wide voltage operation, and proven field reliability are prioritized over ultra-high speed or ultra-low voltage.

FAQ

What is the maximum I²C clock frequency supported by AT24C128-10PU-2.7 at 2.7 V?

The AT24C128-10PU-2.7 supports up to 400 kHz I²C clock frequency when operating at 2.7 V, as specified in Table 5 (AC Characteristics – Extended Temperatures). This is lower than the 1 MHz maximum at 5 V but ensures robust communication in low-voltage industrial environments where noise margins are critical. The timing parameters tLOW ≥1.3 µs and tHIGH ≥0.6 µs must be met by the host controller.

Does AT24C128-10PU-2.7 support page write operations, and what is the page size?

Yes, AT24C128-10PU-2.7 supports 64-byte page write operations. The memory is organized into 256 pages of 64 bytes each, allowing up to 64 sequential bytes to be written in a single I²C transaction. This reduces bus overhead significantly compared to byte-write mode and is essential for efficient firmware parameter updates or bulk calibration data storage.

Is AT24C128-10PU-2.7 pin-compatible with AT24C256-10PU-2.7?

No, AT24C128-10PU-2.7 is not pin-compatible with AT24C256-10PU-2.7 despite identical package and pinout - they differ in memory organization (16,384 × 8 vs. 32,768 × 8) and internal addressing. Using AT24C256-10PU-2.7 as a substitute may cause read/write errors beyond the first 128 Kbit unless firmware explicitly handles the larger address space.

What does the "U" suffix in AT24C128-10PU-2.7 indicate?

The "U" suffix in AT24C128-10PU-2.7 indicates a green, lead-free, and halogen-free package compliant with RoHS Directive 2011/65/EU. It confirms that the 8-lead PDIP body contains no intentionally added lead, cadmium, mercury, hexavalent chromium, polybrominated biphenyls (PBB), or polybrominated diphenyl ethers (PBDE), meeting environmental compliance requirements for industrial and medical equipment.

Can AT24C128-10PU-2.7 be used in automotive applications?

No - AT24C128-10PU-2.7 is not qualified for automotive use. The datasheet explicitly states: "Unless specifically provided otherwise, Atmel products are not suitable for, and shall not be used in, automotive applications." For automotive-grade alternatives, consider AEC-Q100 qualified parts such as STMicroelectronics' M24C128-WMN6TP or Microchip's newer 24AA128-I/P, which undergo extended temperature and reliability validation.