Microchip Technology 24LC128-E/P

Overview

24LC128-E/P from Microchip Technology Inc. is a 128 Kbit (16K × 8) I²C-compatible serial EEPROM designed for nonvolatile data storage in low-power embedded systems. It operates from 2.5V to 5.5V, supports up to 400 kHz I²C clock frequency, features hardware write-protection via the WP pin, and delivers 1 million erase/write cycles with >200 years of data retention. It is used in industrial sensor calibration, power meter configuration, and firmware parameter storage.

For engineers reviewing the 24LC128-E/P datasheet, 24LC128-E/P pinout, 24LC128-E/P application, or 24LC128-E/P equivalent, this page provides verified electrical specs, package mapping, I²C timing constraints, endurance metrics, and validated alternative parts for design-in and supply continuity planning.

Technical Context

The 24LC128-E/P implements a two-wire I²C interface with Schmitt-trigger inputs on SDA and SCL for noise immunity, slope-controlled outputs to suppress ground bounce, and internal address pointer logic enabling current-address, random, and sequential reads across its full 128 Kbit memory space. Its 64-byte page buffer supports efficient burst writes without host-side buffering.

It uses CMOS EEPROM technology with on-chip charge pump for byte/page erase/write operations, self-timed internal write cycles (≤5 ms), and hardware-based write protection that disables all writes when WP = VCC. The device supports cascading up to eight units on one bus using A0–A2 address pins - though only two are usable in MSOP packages.

Key Specifications

Pinout & Package

24LC128-E/P is packaged in an 8-Lead PDIP (Plastic Dual In-line Package), with 0.300-inch body width and through-hole mounting. Pin 1 is marked by a notch or dot; leads are tin-plated and RoHS compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24LC128-E/P, 24AA128-I/P enables lower-voltage operation but sacrifices extended temperature capability, while AT24C128N-10PU-2.7 offers identical form-factor and speed at lower cost but lacks automotive qualification and may differ in write-cycle consistency under thermal stress.

Availability

24LC128-E/P is available at Aetrix Electronics and suitable for industrial sensor calibration, smart energy metering, and automotive body control modules requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 24LC128-E/P 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 Inc. is a U.S.-based semiconductor company specializing in microcontrollers, analog devices, and memory solutions, with global manufacturing and quality certifications including ISO 9001 and IATF 16949.

The 24LC128-E/P belongs to Microchip's 24XX128 family of I²C serial EEPROMs, engineered for robust, low-power nonvolatile storage in automotive, industrial, and medical applications demanding extended temperature operation and high endurance.

FAQ

What is the maximum I²C clock frequency supported by the 24LC128-E/P?

The 24LC128-E/P supports up to 400 kHz I²C clock frequency when VCC is 2.5V or higher. It does not support 1 MHz operation - that capability is exclusive to the 24FC128 variant. At VCC < 2.5V, the 24LC128-E/P is not rated for operation, distinguishing it from the 24AA128 which supports 100 kHz down to 1.7V.

Does the 24LC128-E/P support write protection, and how is it implemented?

Yes, the 24LC128-E/P implements hardware write protection via the WP (Write-Protect) pin. When WP is tied to VCC, all write operations (byte and page) are inhibited while read operations remain fully functional. The WP state is sampled at the Stop bit of each write command, making protection effective without software intervention.

What is the endurance rating of the 24LC128-E/P, and how is it measured?

The 24LC128-E/P is rated for 1,000,000 erase/write cycles per memory page at 25°C and 5.5V, as specified in Table 1-2, Parameter 18. Endurance is defined per physical page (64 bytes), not per individual byte, because page writes refresh the entire page during programming - a key consideration for wear-leveling-aware firmware.

Can multiple 24LC128-E/P devices share the same I²C bus, and how many?

Yes, up to eight 24LC128-E/P devices can share one I²C bus using the A0, A1, and A2 address pins to configure unique 3-bit chip addresses. Each pin must be hardwired to VSS or VCC; floating connections are undefined. This enables scalable memory expansion to 1 Mbit total capacity without additional bus controllers.

What package type is used for the 24LC128-E/P, and what are its key mechanical features?

The 24LC128-E/P uses an 8-Lead PDIP (Plastic Dual In-line Package) with 0.300-inch body width and 0.100-inch lead pitch. It features through-hole mounting, matte tin (Sn) lead finish, RoHS compliance, and JEDEC-standard pinout. The package marking includes "24LC128" followed by temperature grade "E", year/week code, and traceability characters.