Microchip Technology AT24C128N-10SI-1.8

Overview

AT24C128N-10SI-1.8 from Microchip Technology (formerly Atmel) is a 128 Kbit (16,384 × 8) I²C-compatible serial EEPROM optimized for ultra-low-voltage embedded systems. It operates from 1.8 V to 3.6 V, supports 100 kHz I²C bus speed at 1.8 V, features hardware write protection via the WP pin, and delivers 100,000 write cycles with 40-year data retention - ideal for battery-powered sensor nodes and portable medical devices.

For engineers reviewing the AT24C128N-10SI-1.8 datasheet, AT24C128N-10SI-1.8 pinout, AT24C128N-10SI-1.8 application, or AT24C128N-10SI-1.8 equivalent, key selection criteria include 1.8 V operation margin, 64-byte page write capability, Schmitt-triggered noise-immune inputs, industrial temperature range (−40°C to +85°C), and JEDEC SOIC-8 package compatibility.

Technical Context

The AT24C128N-10SI-1.8 implements a standard two-wire (I²C) interface with open-drain SDA/SCL pins, internal address counter for sequential reads, and cascading support for up to four devices on one bus using A0/A1 device address bits. Its memory is organized as 256 pages of 64 bytes each, enabling efficient partial-page writes without cross-page rollover.

It uses a proprietary internal bias circuit on A0/A1 to default to logic low when unconnected, ensuring deterministic addressing. 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-1.8 is housed in an 8-pin JEDEC SOIC (SOIC-8, package code 8S1), 0.150" wide, with standard pinout and footprint compatible with industry-standard PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT24C128N-10SI-1.8, the AT24C128BN-10SI-1.8 offers identical electrical and mechanical compatibility with minor process enhancements, whereas the M95128-DRMN6TP/K requires interface redesign and lacks hardware write protection - making it a functional alternative only when SPI is preferred and security constraints permit.

Availability

AT24C128N-10SI-1.8 is available at Aetrix Electronics and suitable for smart metering, industrial automation, portable diagnostics, automotive body electronics, and battery-powered IoT edge nodes requiring stable component supply across extended product lifecycles.

Supply support for AT24C128N-10SI-1.8 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 broad industrial and automotive qualification expertise.

The AT24C128N-10SI-1.8 belongs to Microchip's legacy AT24C serial EEPROM family, designed specifically for low-voltage, space-constrained embedded systems needing reliable, byte-addressable nonvolatile storage with minimal external components.

FAQ

What is the maximum I²C clock frequency supported by AT24C128N-10SI-1.8 at 1.8 V?

The AT24C128N-10SI-1.8 supports a maximum I²C clock frequency of 100 kHz when operated at 1.8 V. This is specified in the AC Characteristics table under "1.8-volt" column for parameter fSCL. Higher frequencies (up to 400 kHz or 1 MHz) require ≥2.5 V or ≥4.5 V supply respectively - not applicable to the -1.8 suffix variant. The 100 kHz limit ensures setup/hold timing margins are met under worst-case low-voltage conditions.

Does AT24C128N-10SI-1.8 support page write operations, and what is the page size?

Yes, AT24C128N-10SI-1.8 supports page write operations with a fixed page size of 64 bytes. This allows up to 64 sequential bytes to be written in a single I²C transaction after the initial address byte, improving write efficiency versus byte-by-byte programming. The internal address counter auto-increments within the page boundary; crossing the 64-byte boundary wraps to the start of the same page unless a new address is issued.

What is the purpose of the NC pin on AT24C128N-10SI-1.8, and how should it be handled on the PCB?

The NC (No Connect) pin on AT24C128N-10SI-1.8 is internally unconnected and serves no electrical function. Per the datasheet Pin Description and Package Drawings, it must remain unconnected on the PCB - neither tied to GND, VCC, nor routed. Leaving it floating is acceptable; however, routing or soldering to this pin may cause mechanical stress or unintended coupling and is strictly prohibited.

How does the Write Protect (WP) pin function on AT24C128N-10SI-1.8, and what happens when it is left unconnected?

When WP is tied to VCC, all write operations to AT24C128N-10SI-1.8 are inhibited; when tied to GND, full read/write access is enabled. If left unconnected, WP is internally pulled down to GND via a proprietary bias circuit, resulting in normal write capability. This default behavior simplifies designs where write protection is not required, eliminating the need for an external pull-down resistor.

Is AT24C128N-10SI-1.8 qualified for industrial temperature operation, and what is its specified range?

Yes, AT24C128N-10SI-1.8 is explicitly qualified for industrial temperature operation, with a specified range of −40°C to +85°C. This is confirmed by the "-SI" suffix in the part number (per Ordering Information table) and reinforced by Absolute Maximum Ratings and DC/AC Characteristics test conditions covering TA = −40°C to +85°C at VCC = 1.8 V to 3.6 V.