Microchip Technology 24LC64F-E/P

Overview

24LC64F-E/P from Microchip Technology Inc. is a 64 Kbit I²C-compatible serial EEPROM organized as 8K × 8-bit memory, operating from 2.5V to 5.5V with 400 kHz max clock frequency and industrial/automotive temperature range (–40°C to +125°C). It features hardware write-protect for the upper 1/4 array (1800h–1FFFh), 32-byte page write buffer, and Schmitt-trigger inputs for noise immunity - deployed in automotive body control modules for calibration storage.

For engineers reviewing the 24LC64F-E/P datasheet, 24LC64F-E/P pinout, 24LC64F-E/P application, or 24LC64F-E/P equivalent, key selection criteria include VCC min (2.5V), WP-enabled quarter-array protection, automotive-grade reliability (E-temp), and PDIP-8 package compatibility with legacy through-hole designs.

Technical Context

The 24LC64F-E/P implements a standard two-wire I²C slave interface with fixed 7-bit address prefix '1010' and three programmable chip-select bits (A2–A0), enabling up to eight devices on one bus. Its internal address counter supports current-address, random, and sequential read modes, while page write operations are constrained to 32-byte boundaries without wraparound across physical pages.

Write protection is sampled at the Stop bit of each write command; tying WP to VCC disables writes only to addresses 1800h–1FFFh, leaving reads fully functional. The device uses self-timed erase/write cycles with typical 5 ms page write time and supports acknowledge polling to detect write completion without fixed delays.

Key Specifications

Pinout & Package

24LC64F-E/P is supplied in an 8-lead plastic dual in-line package (PDIP) with 0.300" body width, RoHS-compliant matte tin plating, and standard through-hole footprint compatible with IPC-7351B.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24LC64T-I/P, the 24LC64F-E/P adds automotive-grade reliability and hardware write-protect; compared with AT24C64D-SSHM-T, it trades speed and voltage flexibility for deterministic, pin-level security against accidental writes - critical in safety-regulated systems.

Availability

24LC64F-E/P is available at Aetrix Electronics and suitable for automotive electronics, industrial PLCs, and medical device manufacturing requiring stable component supply across extended product lifecycles.

Supply support for 24LC64F-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 leading provider of microcontrollers, analog devices, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 24LC64F belongs to Microchip's 24XX64F family of I²C serial EEPROMs engineered specifically for automotive and industrial applications demanding high reliability, extended temperature operation, and hardware-level data integrity safeguards.

FAQ

What is the minimum VCC voltage required for reliable operation of the 24LC64F-E/P?

The 24LC64F-E/P requires a minimum VCC of 2.5V for guaranteed operation across its full automotive temperature range (–40°C to +125°C). Operation below 2.5V is not specified and may result in undefined behavior, including failed writes or incorrect address decoding. This differs from the 24AA64F variant, which supports down to 1.7V but only for industrial temperature grades.

How does the WP pin function on the 24LC64F-E/P, and what memory region does it protect?

The WP pin on the 24LC64F-E/P is an active-high hardware write-protect input. When tied to VCC, it disables all write operations to the upper 1/4 of the memory array - specifically addresses 1800h through 1FFFh (16,384 bytes). Reads remain fully functional across the entire 64 Kbit space regardless of WP state. This protection is sampled at the Stop bit of each write command.

Can the 24LC64F-E/P be used interchangeably with the 24LC64F-I/P in a design?

No - the 24LC64F-E/P and 24LC64F-I/P are not interchangeable without validation. While both share identical electrical specifications and pinout, the E-grade version is qualified for –40°C to +125°C operation and meets automotive reliability standards (e.g., AEC-Q100), whereas the I-grade is limited to –40°C to +85°C. Substituting I-grade in an E-grade design risks parametric failure at elevated temperatures.

What is the maximum number of 24LC64F-E/P devices that can share a single I²C bus, and how is addressing managed?

Up to eight 24LC64F-E/P devices can share one I²C bus using the three hardware address pins A0, A1, and A2. Each device is assigned a unique 3-bit slave address by hardwiring these pins to VSS or VCC, resulting in addresses ranging from 1010000b to 1010111b (0x50–0x57). The SOT-23 variant lacks these pins and uses a fixed address, but the 24LC64F-E/P in PDIP includes all three for flexible multi-device configurations.

Does the 24LC64F-E/P support page write operations, and what is the buffer size?

Yes, the 24LC64F-E/P supports page write operations with a 32-byte page buffer. A single I²C transaction can write up to 32 contiguous bytes starting from any address aligned to a 32-byte boundary (e.g., 0000h, 0020h, 0040h). Attempting to cross a page boundary causes wraparound within the same page - software must enforce alignment to avoid unintended overwrites.