Microchip Technology 24LC65/P

Overview

24LC65/P from Microchip Technology Inc. is a 64 Kbit (8K × 8) I²C-compatible serial EEPROM with programmable high-endurance memory blocks, 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, delivers 3 mA peak write current, and supports industrial temperature range (−40°C to +85°C) in 8-pin PDIP package. Used for firmware parameter storage in embedded controllers requiring field-updatable nonvolatile data.

For engineers reviewing the 24LC65/P datasheet, 24LC65/P pinout, 24LC65/P application, or 24LC65/P equivalent, key selection considerations include its relocatable 4K-bit ultra-high-endurance block (10M cycles), configurable security protection for up to 15 × 4K blocks, Schmitt-triggered noise-immune I²C interface, self-timed write cycles, and compatibility with multi-device I²C bus topologies.

Technical Context

The 24LC65/P implements a two-wire I²C slave architecture with addressable 8-bit word access, internal address pointer auto-increment, and hardware-controlled acknowledge polling. Its memory map includes one user-programmable 4K-bit high-endurance block (10,000,000 E/W cycles) and 60K bits of standard endurance memory (1,000,000 E/W cycles).

It features an 8-page (64-byte) FIFO input cache enabling burst writes without host timing constraints, programmable block-level write protection via configuration byte, and V_DD monitor circuitry preventing inadvertent writes during brown-out conditions. All I/O pins include Schmitt triggers and input filtering for robust operation on noisy buses.

Key Specifications

Pinout & Package

8-pin plastic dual in-line package (PDIP), through-hole mount, RoHS-compliant. Pin 1 marked by notch or dot; pin numbering follows standard DIP convention (counterclockwise from notch).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24LC65/P, 24AA65/P offers broader voltage flexibility but sacrifices industrial temperature capability, while AT24C64D-PU provides basic EEPROM functionality at lower cost but omits advanced features essential for secure, high-cycle-count embedded storage.

Availability

24LC65/P is available at Aetrix Electronics and suitable for smart energy metering, industrial PLC configuration storage, medical diagnostic device calibration, and automotive body control module applications requiring stable component supply across extended product lifecycles.

Supply support for 24LC65/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 memory solutions for embedded control applications.

The 24LC65/P belongs to Microchip's "Smart Serial EEPROM" product line, designed specifically for systems needing field-updatable, high-reliability nonvolatile storage with programmable endurance and security - targeting industrial, medical, and automotive subsystems.

FAQ

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

24LC65/P supports 400 kHz fast-mode I²C operation when V_CC is between 4.5 V and 6.0 V. At lower supply voltages (2.5–4.5 V), it operates at standard-mode 100 kHz. This dual-speed capability allows seamless integration into both legacy and modern microcontroller platforms without bus-speed negotiation logic.

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

Yes, 24LC65/P has open-drain SDA and SCL pins and requires external pull-up resistors. For 400 kHz operation, a 2 kΩ resistor to V_CC is recommended; for 100 kHz, a 10 kΩ resistor suffices. These values ensure proper rise times per I²C specification while minimizing power consumption during bus idle states.

How many 24LC65/P devices can share the same I²C bus?

Up to eight 24LC65/P devices can operate on a single I²C bus using unique combinations of A0, A1, and A2 address pins. Each device occupies a distinct 7-bit slave address (1010xxx), enabling up to 512 Kbits of contiguous EEPROM memory space when all eight are connected.

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

No - the high-endurance block location is set during initial configuration and cannot be changed if any security protection has been enabled with length > 0. If security is not programmed, the block may be reconfigured; however, once security is activated, the high-endurance setting remains fixed at its programmed address to ensure data integrity guarantees.

What is the write endurance of the standard memory array in the 24LC65/P?

The standard memory array of the 24LC65/P is rated for 1,000,000 erase/write cycles at 25°C. This applies to the 60 Kbits outside the programmable 4K-bit high-endurance block. Endurance is specified per byte and validated across the full industrial temperature range (−40°C to +85°C).