Microchip Technology 24LC65-I/P

Overview

24LC65-I/P from Microchip Technology Inc. is a 64 Kbit (8K × 8) I²C-compatible serial EEPROM with programmable high-endurance memory blocks, 2 ms typical byte/page write cycle time, and dual-speed I²C support (100 kHz at 1.8–4.5 V, 400 kHz at 4.5–6.0 V). It operates across industrial temperature range (−40°C to +85°C) in 8-pin PDIP package and is used for firmware parameter storage in embedded controllers requiring field-updatable nonvolatile data.

For engineers reviewing the 24LC65-I/P datasheet, 24LC65-I/P pinout, 24LC65-I/P application, or 24LC65-I/P equivalent, key selection criteria include its 64-byte input cache for burst writes, configurable 4K high-endurance block (10M cycles), Schmitt-triggered noise-immune I²C interface, programmable security for up to 15 protected blocks, and compatibility with multi-device bus topologies supporting up to 512 Kbits total memory.

Technical Context

The 24LC65-I/P 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 mapping (10M-cycle 4K block + 1M-cycle remainder), and on-chip voltage monitoring to prevent write corruption during brown-out conditions.

It supports three read modes (current address, random, sequential) and two write modes (byte and page), with acknowledge polling for write completion detection. All I/O pins feature Schmitt-trigger inputs and output slope control to suppress ground bounce and EMI, meeting I²C Fast Mode timing requirements at 400 kHz when VCC ≥ 4.5 V.

Key Specifications

Pinout & Package

8-pin Plastic Dual In-line Package (PDIP), 0.3 inch width, through-hole mounting. RoHS-compliant, Pb-free finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24LC65-I/P, the 24AA65-I/P extends low-voltage operability while maintaining full feature parity, whereas the AT24C64D-PU sacrifices endurance granularity and security for lower unit cost-making it appropriate only for non-critical, static configuration storage.

Availability

24LC65-I/P is available at Aetrix Electronics and suitable for industrial control systems, automotive body electronics, and medical diagnostics equipment requiring stable component supply and long-lifecycle support.

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

The 24LC65-I/P belongs to Microchip's "Smart Serial EEPROM" product line, designed specifically for systems needing field-updatable, secure, and wear-leveling-capable nonvolatile storage in space- and power-constrained environments.

FAQ

What is the maximum I²C clock frequency supported by the 24LC65-I/P?

At VCC ≥ 4.5 V, the 24LC65-I/P supports Fast Mode I²C operation up to 400 kHz. Below 4.5 V (down to 2.5 V), it operates in Standard Mode with a maximum clock frequency of 100 kHz. This dual-speed capability ensures interoperability across both legacy and high-performance I²C buses without external clock dividers or protocol translation.

Does the 24LC65-I/P require an external pull-up resistor on the SDA and SCL lines?

Yes, the 24LC65-I/P has open-drain SDA and SCL outputs and requires external pull-up resistors to VCC. For 100 kHz operation, a 10 kΩ resistor is typical; for 400 kHz, a 2 kΩ resistor is recommended to meet rise-time specifications. The exact value depends on bus capacitance and must comply with I²C bus timing requirements defined in the 24LC65-I/P datasheet.

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

No-the high-endurance block location is set during initial configuration and cannot be changed afterward if any security block has been programmed with length > 0. If security is not enabled, the block can be reprogrammed; however, once security is activated, the high-endurance setting becomes fixed. The default location is the highest 4K block (0x1E00–0x1FFF) if not explicitly configured.

How does the 64-byte input cache improve write performance in the 24LC65-I/P?

The 64-byte input cache allows the host MCU to stream up to 64 bytes of data over I²C without waiting for internal write cycles to complete. Once a STOP condition is issued, the 24LC65-I/P executes background page writes at up to 5 ms per 8-byte page. This decouples bus communication from flash programming latency, enabling faster bulk updates and reduced MCU blocking time compared to byte-write-only EEPROMs.

Is the 24LC65-I/P pin-compatible with other members of the 24XX65 family such as the 24AA65-I/P?

Yes, the 24LC65-I/P is fully pin-compatible and functionally interchangeable with the 24AA65-I/P and 24C65-I/P in the 8-pin PDIP package. All share identical pinout, memory organization, command set, and register mapping. Differences lie only in voltage range and temperature grading-24LC65-I/P is rated for 2.5–6.0 V and industrial temperature, while 24AA65-I/P supports 1.8 V minimum and 24C65-I/P adds automotive qualification.