Microchip Technology AT24C128N-10SI-2.5

Overview

AT24C128N-10SI-2.5 from Microchip Technology (formerly Atmel) is a 128 Kbit (16,384 × 8) two-wire serial EEPROM optimized for industrial temperature operation (−40°C to +85°C), low-voltage compatibility (2.5V to 5.5V), and noise-immune I²C communication at up to 400 kHz. It features hardware write protection via the WP pin, 64-byte page write capability, and 100,000 write cycles endurance - deployed in embedded controllers, power management units, and sensor calibration storage.

For engineers reviewing the AT24C128N-10SI-2.5 datasheet, AT24C128N-10SI-2.5 pinout, AT24C128N-10SI-2.5 application, or AT24C128N-10SI-2.5 equivalent, key selection considerations include its industrial-grade 2.5V–5.5V supply range, 400 kHz I²C speed at 2.5V, 64-byte page write mode, WP-enabled hardware data lock, and SOIC-8 (8S1) package with 0.150" width.

Technical Context

The AT24C128N-10SI-2.5 implements a standard I²C-compatible two-wire interface with open-drain SDA and edge-triggered SCL, supporting bidirectional data transfer and 7-bit device addressing with A0/A1 inputs enabling up to four devices on one bus. Its internal architecture organizes memory as 256 pages of 64 bytes each, with automatic address incrementing during sequential reads/writes and roll-over behavior at page boundaries.

It uses Schmitt-trigger inputs with filtering for robust noise immunity, supports acknowledge polling during write cycles, and enters low-power standby mode after STOP condition or power-up. The WP pin provides dual-mode protection: hardware lock when tied to VCC, and software-controlled lock via dynamic high-level assertion before write commands.

Key Specifications

Pinout & Package

AT24C128N-10SI-2.5 is packaged in an 8-lead, 0.150" wide JEDEC SOIC (package code 8S1), compliant with RoHS and rated for industrial temperature operation (−40°C to +85°C).

Key Features

Applications

Equivalent & Alternatives

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

Compared with M24C128-WMN6TP and CAT24C128WI-GT3, AT24C128N-10SI-2.5 delivers the lowest industrial-grade standby current (0.5 µA) and guaranteed 400 kHz I²C performance at 2.5V - making it optimal for battery-constrained or mixed-voltage embedded systems requiring deterministic timing and robust data protection.

Availability

AT24C128N-10SI-2.5 is available at Aetrix Electronics and suitable for smart metering, industrial PLCs, medical sensor calibration, and automotive body control modules requiring stable component supply across extended lifecycle programs.

Supply support for AT24C128N-10SI-2.5 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 is a global semiconductor company specializing in microcontrollers, analog devices, and nonvolatile memory solutions, with a focus on reliability, longevity, and embedded system integration.

The AT24C128 family was designed for robust, low-power serial data storage in industrial, automotive, and consumer systems - emphasizing noise immunity, flexible voltage operation, and hardware-based data security.

FAQ

What is the maximum I²C clock frequency supported by AT24C128N-10SI-2.5 at 2.5V?

The AT24C128N-10SI-2.5 supports up to 400 kHz I²C clock frequency when operated at 2.5V, as specified in its AC characteristics table. This is lower than its 1 MHz rating at 5V but ensures reliable timing margins under low-voltage industrial conditions. The device automatically adapts to the host controller's SCL rate within this limit, and no configuration register is required to enable this speed.

Does AT24C128N-10SI-2.5 require external pull-up resistors on SDA and SCL lines?

Yes, AT24C128N-10SI-2.5 requires external pull-up resistors on both SDA and SCL lines because its I²C interface uses open-drain outputs. Typical values range from 2.2 kΩ to 10 kΩ depending on bus capacitance and desired rise time; 4.7 kΩ is commonly used for standard-mode (100 kHz) and fast-mode (400 kHz) operation with ≤400 pF total bus load. The AT24C128N-10SI-2.5 itself does not integrate pull-ups.

How does the WP pin function on AT24C128N-10SI-2.5, and what happens if it is left unconnected?

On AT24C128N-10SI-2.5, the WP pin provides hardware write protection: tying it to VCC disables all write operations, while connecting it to GND enables full read/write access. If left unconnected, an internal pull-down circuit asserts WP low, allowing normal writes. This default behavior simplifies prototyping but requires deliberate routing to VCC in production for secure parameter locking - no software command can override this hardware state.

What package type and dimensions does AT24C128N-10SI-2.5 use?

AT24C128N-10SI-2.5 uses an 8-lead, 0.150" wide JEDEC-standard SOIC package (package code 8S1), measuring 4.90 mm × 3.91 mm × 1.75 mm (L × W × H). It complies with IPC-7351B footprint standards and is compatible with standard SOIC-8 reflow profiles. The "SI" suffix explicitly denotes this SOIC-8 industrial-grade variant, distinguishing it from PDIP, TSSOP, or dBGA versions in the same family.

Can AT24C128N-10SI-2.5 be used alongside other AT24C128 variants on the same I²C bus?

Yes, AT24C128N-10SI-2.5 can share an I²C bus with up to three other AT24C128 devices (e.g., AT24C128-10PI-2.7 or AT24C128W-10SI-2.5) using unique combinations of A0 and A1 pins. Each device responds only to its assigned 7-bit address (0x50–0x53), enabling modular system design with distributed nonvolatile storage. All variants maintain identical I²C protocol timing and command structure, ensuring interoperability regardless of voltage option or package.