Microchip Technology 24LC64FT-E/OT

Overview

24LC64FT-E/OT 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 low standby current (1 µA max) - deployed in automotive body control modules for calibration storage.

For engineers reviewing the 24LC64FT-E/OT datasheet, 24LC64FT-E/OT pinout, 24LC64FT-E/OT application, or 24LC64FT-E/OT equivalent, key selection criteria include automotive-grade temperature compliance, quarter-array hardware write-protection, I²C bus timing at 400 kHz under 2.5V–5.5V VCC, and SOT-23 package footprint constraints.

Technical Context

The 24LC64FT-E/OT implements a two-wire I²C interface with Schmitt-trigger inputs on SDA/SCL for noise immunity and slope-controlled outputs to suppress ground bounce. Its internal address counter supports current-address, random, and sequential read modes, while acknowledge polling enables precise write-cycle completion detection without fixed delays.

It uses a single-block 8K × 8-bit EEPROM array with self-timed erase/write cycles, 5 ms typical page write time, and hardware-based write protection tied to the WP pin state at the Stop bit. The SOT-23 package omits A0/A1/A2 pins, fixing device address to 1010000b (0xA0 write / 0xA1 read) per I²C protocol.

Key Specifications

Pinout & Package

24LC64FT-E/OT is supplied in a Pb-free, RoHS-compliant 5-lead SOT-23 package (1.6 mm × 2.8 mm × 1.1 mm), optimized for high-density automotive PCB layouts. Unlike PDIP/SOIC variants, this variant lacks A0/A1/A2 pins and uses a fixed I²C slave address.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24LC64-I/SN, 24LC64FT-E/OT adds automotive qualification and SOT-23 miniaturization; versus AT24C64D-SSHM-T, it trades 1 MHz capability for tighter integration with legacy 400 kHz automotive microcontrollers and simplified voltage domain management.

Availability

24LC64FT-E/OT is available at Aetrix Electronics and suitable for automotive body control units, industrial sensor nodes, medical infusion pumps, and smart energy meters requiring stable component supply across extended product lifecycles.

Supply support for 24LC64FT-E/OT 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 microcontroller, analog, FPGA, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 24LC64F family was designed specifically for automotive and industrial applications demanding high reliability, extended temperature operation, and hardware-level data protection - with the 24LC64FT-E/OT variant optimized for space-constrained, high-vibration environments.

FAQ

What is the I²C slave address of the 24LC64FT-E/OT?

The 24LC64FT-E/OT uses a fixed 7-bit I²C slave address of 0x50 (write) / 0x51 (read) because its SOT-23 package omits A0/A1/A2 pins. This address is hardwired per the device's internal logic and cannot be modified by external pin strapping - ensuring deterministic bus behavior in multi-device automotive networks where address collisions must be avoided.

Does the 24LC64FT-E/OT support 1 MHz I²C operation?

No, the 24LC64FT-E/OT supports up to 400 kHz I²C clock frequency at VCC ≥ 2.5V. The 1 MHz capability is exclusive to the 24FC64F variant (e.g., 24FC64FT-E/OT). Using the 24LC64FT-E/OT in a 1 MHz system will result in timing violations and communication failures - confirm clock rate compatibility before integrating 24LC64FT-E/OT into high-speed I²C buses.

How does hardware write-protection work on the 24LC64FT-E/OT?

When the WP pin of the 24LC64FT-E/OT is driven high (VCC), write operations to memory addresses 1800h–1FFFh (upper 1/4 array) are blocked; reads remain fully functional. The protection state is sampled at the Stop bit of each write command - toggling WP mid-cycle has no effect. This mechanism provides deterministic, zero-software-overhead protection for safety-critical calibration data stored in that region.

What is the maximum write cycle time for a full 32-byte page on the 24LC64FT-E/OT?

The 24LC64FT-E/OT has a typical page write time of 5 ms, with no specified maximum value in the datasheet. In practice, designs must allow ≥5 ms after issuing a Stop condition before initiating the next I²C transaction. Acknowledge polling - sending repeated Start + control byte (R/W=0) until an ACK is received - is the recommended method to detect write completion without fixed delays.

Is the 24LC64FT-E/OT pin-compatible with other 24LC64F variants in SOIC or TSSOP packages?

No, the 24LC64FT-E/OT is not pin-compatible with SOIC or TSSOP versions due to its 5-lead SOT-23 package and absence of A0/A1/A2 pins. SOIC-8 and TSSOP-8 variants have eight leads including three address inputs, while the SOT-23 variant consolidates functionality into five leads with fixed addressing. PCB layout and firmware addressing logic must be redesigned when migrating between these packages.