Microchip Technology 24AA64FT-I/SN

Overview

24AA64FT-I/SN from Microchip Technology Inc. is a 64 Kbit I²C-compatible serial EEPROM organized as 8K × 8-bit memory, operating from 1.7V to 5.5V with 400 kHz max clock frequency and industrial temperature range (–40°C to +85°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 embedded control modules, sensor calibration storage, and power management firmware retention.

For engineers reviewing the 24AA64FT-I/SN datasheet, 24AA64FT-I/SN pinout, 24AA64FT-I/SN application, or 24AA64FT-I/SN equivalent, key selection criteria include low-voltage operation down to 1.7V, I²C bus compatibility up to 400 kHz, 1 μA standby current, and TSSOP-8 package footprint with validated A0–A2 address pin mapping.

Technical Context

The 24AA64FT-I/SN implements a standard two-wire I²C slave interface with fixed 7-bit device address prefix '1010' and three programmable chip-select bits (A2–A0), enabling up to eight devices on a single bus. Its internal architecture includes an 8K × 8-bit nonvolatile memory array, 32-byte page write buffer, and self-timed erase/write cycle with no external timing components required.

Write protection is implemented via the WP pin, which-when tied to VCC-blocks writes only to addresses 1800h–1FFFh while permitting full read access. The device uses Schmitt-trigger inputs on SDA and SCL with 50 ns spike suppression and hysteresis of 0.05 VCC, ensuring robust operation in electrically noisy environments typical of industrial control and automotive subsystems.

Key Specifications

Pinout & Package

24AA64FT-I/SN is supplied in an 8-lead TSSOP package (3.0 mm × 4.4 mm, 0.65 mm pitch), RoHS-compliant and Pb-free. Pin assignments are identical to SOIC and PDIP variants, supporting drop-in replacement across Microchip's 24XX64F family.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24AA64FT-I/SN, the 24LC64FT-I/SN offers identical functionality above 2.5V but excludes sub-2.5V operation, while the AT24C64D-SSHM-T sacrifices hardware write-protection for lower unit cost - making 24AA64FT-I/SN the optimal choice for 1.7V–2.5V systems requiring tamper-resistant configuration storage.

Availability

24AA64FT-I/SN is available at Aetrix Electronics and suitable for industrial sensor calibration, smart meter firmware storage, and automotive body control modules requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for 24AA64FT-I/SN 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, and Flash-IP solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 24AA64F series was designed specifically for low-power, I²C-based nonvolatile data storage in space- and energy-constrained embedded systems - emphasizing reliability, voltage flexibility, and ease of integration with mainstream MCUs.

FAQ

What is the maximum I²C clock frequency supported by the 24AA64FT-I/SN?

The 24AA64FT-I/SN supports up to 400 kHz I²C clock frequency when VCC is 2.5V or higher. At VCC between 1.7V and 2.5V, the maximum clock rate drops to 100 kHz per DS22154B specifications. This dual-speed capability ensures compatibility with both legacy 100 kHz buses and modern high-throughput 400 kHz implementations. The 24AA64FT-I/SN does not support 1 MHz operation - that capability is exclusive to the 24FC64F variant.

How does the hardware write-protect feature work on the 24AA64FT-I/SN?

The WP pin on the 24AA64FT-I/SN provides hardware-level protection for the upper 1/4 memory array (addresses 1800h–1FFFh). When WP is tied to VCC, write operations to this region are blocked while reads remain fully functional. If WP is connected to VSS, write protection is disabled across the entire memory. The pin state is sampled at the Stop bit of each write command, so toggling WP mid-operation has no effect - ensuring deterministic behavior during firmware updates.

Can multiple 24AA64FT-I/SN devices share the same I²C bus?

Yes, up to eight 24AA64FT-I/SN devices can operate on a single I²C bus using the A0, A1, and A2 address pins to configure unique 7-bit slave addresses. Each pin must be hardwired to either VCC or VSS to set its logic level, forming a 3-bit chip-select code that combines with the fixed '1010' control code. This enables scalable memory expansion up to 512 Kbit without additional address decoding logic - a key advantage in multi-sensor or modular industrial systems.

What is the page write buffer size of the 24AA64FT-I/SN, and how does it improve performance?

The 24AA64FT-I/SN features a 32-byte page write buffer, allowing up to 32 bytes of data to be written in a single I²C transaction. This reduces the number of required Start/Stop sequences and ACK handshakes compared to byte-wise writes - cutting total bus time by approximately 32× for full-page updates. Because page boundaries align to 32-byte intervals (e.g., 0000h–001Fh), software must ensure write commands do not cross boundaries to avoid data wraparound.

Is the 24AA64FT-I/SN compatible with 1.8V microcontroller I/O interfaces?

Yes, the 24AA64FT-I/SN is fully compatible with 1.8V systems: its VCC range starts at 1.7V, and its I²C interface meets standard voltage thresholds - VIH = 0.7×VCC (≥1.26V at 1.8V) and VIL = 0.3×VCC (≤0.54V). With Schmitt-trigger inputs and 50 ns spike suppression, it tolerates noise common in mixed-voltage boards. No level shifters are needed when interfacing with 1.8V MCUs like the MSP430FRxx or STM32L0 series.