Microchip Technology 24LC65/SM

Overview

24LC65/SM from Microchip Technology Inc. is a 64 Kbit (8K × 8) I²C-compatible serial EEPROM with programmable high-endurance memory block, 64-byte input cache, and dual-speed I²C interface (100 kHz at 1.8–4.5 V, 400 kHz at 4.5–6.0 V). It operates from 2.5 V to 6.0 V, supports industrial temperature range (−40°C to +85°C), and is packaged in 8-pin SOIJ. It serves as nonvolatile data storage in embedded systems requiring frequent parameter updates, such as industrial sensor calibration tables.

For engineers reviewing the 24LC65/SM datasheet, 24LC65/SM pinout, 24LC65/SM application, or 24LC65/SM equivalent, key selection considerations include its 10 million-cycle high-endurance block, configurable security protection across up to 15 × 4K blocks, Schmitt-triggered noise-immune I²C interface, and 2 ms typical byte write cycle time - all critical for robust field-deployed firmware and configuration storage.

Technical Context

The 24LC65/SM implements a two-wire I²C slave interface with hardware-addressable device select pins (A0–A2), enabling up to eight devices on one bus. Its internal architecture includes a 64-byte FIFO page cache, dual endurance memory regions (10M cycles for 4K-bit high-endurance block; 1M cycles for remaining 60K bits), and programmable security logic that locks write access to user-defined 4K-block ranges.

It features integrated V_CC monitoring for power-fail write protection, self-timed erase/write cycles, and slope-controlled outputs to suppress ground bounce. The SDA and SCL inputs incorporate Schmitt triggers and digital filtering (50 ns spike suppression), ensuring reliable operation in electrically noisy environments without external RC filtering.

Key Specifications

Pinout & Package

24LC65/SM is housed in an 8-pin SOIJ (Small Outline Integrated Circuit, J-bend) surface-mount package, RoHS-compliant and Pb-free. Pin count and physical layout match industry-standard 8-pin SOIC but with gull-wing leads replaced by J-leads for improved moisture resistance and board-level reliability in humid environments.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT24C64D-SSHM-T and BR24G64FJ-WE2, the 24LC65/SM uniquely delivers field-programmable high-endurance memory and granular security - making it the only option among the three capable of safely storing both frequently rewritten calibration data and immutable firmware parameters in a single device.

Availability

24LC65/SM is available at Aetrix Electronics and suitable for industrial sensor calibration, medical device configuration, automotive body control modules, and smart energy metering requiring stable component supply across extended product lifecycles.

Supply support for 24LC65/SM 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 manufacturer specializing in microcontrollers, analog devices, and nonvolatile memory solutions for embedded control applications.

The 24LC65/SM belongs to Microchip's "Smart Serial EEPROM" product line, designed specifically for systems needing differentiated endurance, on-the-fly security configuration, and noise-resilient I²C communication in harsh industrial and automotive environments.

FAQ

What is the maximum I²C clock frequency supported by the 24LC65/SM?

The 24LC65/SM supports 100 kHz I²C operation across its full 2.5–6.0 V V_CC range, and 400 kHz fast-mode operation when V_CC is between 4.5 V and 6.0 V. This dual-speed capability allows seamless integration with both legacy and modern microcontrollers without requiring external clock dividers or protocol translation.

Does the 24LC65/SM require external pull-up resistors on SDA and SCL lines?

Yes, the 24LC65/SM has open-drain SDA and SCL pins and requires external pull-up resistors. For 100 kHz operation, a 10 kΩ resistor to V_CC is recommended; for 400 kHz, a 2 kΩ resistor ensures proper rise time compliance per I²C specification. The 24LC65/SM itself does not integrate internal pull-ups.

Can the high-endurance block of the 24LC65/SM be relocated after initial programming?

No - the location of the 10M-cycle high-endurance block in the 24LC65/SM is programmable only once, and cannot be changed after the security option has been set with a length greater than zero. If not explicitly programmed, the default high-endurance block starts at address 0x1E00 (upper 4K-bit region). This immutability ensures deterministic endurance behavior in certified applications.

How does the 24LC65/SM handle power loss during a write operation?

The 24LC65/SM incorporates on-chip V_CC monitoring that automatically suspends write cycles if V_CC drops below a safe threshold. Combined with write-cycle auto-termination upon Stop condition receipt, this prevents partial writes and data corruption. No external power-fail circuitry is needed for reliable operation of the 24LC65/SM in brownout conditions.

Is the 24LC65/SM pin-compatible with other 8-pin serial EEPROMs like the 24C02 or 24LC256?

No - while the 24LC65/SM shares the same 8-pin SOIJ footprint and basic I²C pinout (A0–A2, VSS, SDA, SCL, VCC, NC), its internal register map, security command protocol, and high-endurance block addressing differ fundamentally from smaller-density EEPROMs like the 24C02 or larger ones like the 24LC256. Direct substitution would require firmware rework to handle the unique configuration byte structure and cache management of the 24LC65/SM.