Microchip Technology 24AA64F-I/MS

Overview

24AA64F-I/MS 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 industrial temperature range (–40°C to +85°C). It features 32-byte page write buffer, hardware write-protect for upper 1/4 array (1800h–1FFFh), and Schmitt-trigger inputs for noise immunity. Used in low-power embedded systems for parameter storage, calibration data retention, and firmware configuration.

For engineers reviewing the 24AA64F-I/MS datasheet, 24AA64F-I/MS pinout, 24AA64F-I/MS application, or 24AA64F-I/MS equivalent, key selection criteria include 1.7V minimum VCC operation, 400 kHz I²C clock support at 2.5–5.5V, 1 μA max standby current, and MSOP-8 package compatibility with space-constrained PCB layouts.

Technical Context

The 24AA64F-I/MS implements a two-wire I²C interface with slave addressing via A0–A2 pins (hardwired or externally driven), supporting up to eight devices on one bus. Its internal address counter enables sequential reads across full 8K-word memory space with automatic rollover from 1FFFh to 0000h.

Write operations are self-timed: byte writes complete in ≤5 ms, and page writes (up to 32 bytes within same physical page) also execute in ≤5 ms. The WP pin provides hardware-level protection of the upper 16Kb (1800h–1FFFh), sampled only at the Stop bit of each write command - toggling WP mid-cycle has no effect.

Key Specifications

Pinout & Package

24AA64F-I/MS is housed in an 8-lead MSOP package (3.0 mm × 3.0 mm × 1.0 mm body, 0.65 mm pitch), optimized for high-density PCB layouts while maintaining hand-solderability and thermal performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24LC64F-I/MS, the 24AA64F-I/MS enables true 1.8V operation and lower standby current, while AT24C64D-MAHM-T trades hardware WP for superior ESD robustness - making 24AA64F-I/MS optimal for ultra-low-power, safety-critical parameter storage where voltage headroom is constrained.

Availability

24AA64F-I/MS is available at Aetrix Electronics and suitable for smart sensor nodes, industrial PLC modules, medical handheld diagnostics, and automotive body control units requiring stable component supply across extended production lifecycles.

Supply support for 24AA64F-I/MS 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, FPGA, and memory solutions, serving industrial, automotive, and consumer markets with vertically integrated silicon and development tools.

The 24AA64F-I/MS belongs to Microchip's 24XX64F family of I²C EEPROMs, designed specifically for low-voltage, low-power embedded systems needing reliable nonvolatile storage with minimal footprint and bill-of-materials impact.

FAQ

What is the minimum VCC voltage supported by the 24AA64F-I/MS?

The 24AA64F-I/MS operates down to 1.7V, enabling direct use with 1.8V logic families and ultra-low-power microcontrollers without level-shifting circuitry. This specification is validated across the full industrial temperature range (–40°C to +85°C) and is a key differentiator from the 24LC64F variant, which requires ≥2.5V. The 24AA64F-I/MS maintains full I²C functionality, including 400 kHz clock support, at 1.7V.

How does the hardware write-protect feature work on the 24AA64F-I/MS?

The WP pin on the 24AA64F-I/MS controls write access to the upper 1/4 memory array (addresses 1800h–1FFFh). When WP is tied to VCC, writes to that region are inhibited while reads remain fully functional; tying WP to VSS enables full read/write access. The pin is sampled only at the Stop bit of each write command - changing WP state mid-transaction has no effect. This provides tamper-resistant storage for critical firmware or security parameters.

Can multiple 24AA64F-I/MS devices share the same I²C bus?

Yes - the 24AA64F-I/MS supports up to eight devices on a single I²C bus using its three hardware address pins (A0, A1, A2). Each device is assigned a unique 3-bit slave address (1010xxx), allowing a total addressable space of 512 Kbit. Address pins are hardwired to VSS or VCC and must be stable before device initialization; they are not available in SOT-23 variants but are fully implemented in the MSOP-8 package of the 24AA64F-I/MS.

What is the maximum I²C clock frequency for the 24AA64F-I/MS?

The 24AA64F-I/MS supports up to 400 kHz I²C clock frequency when VCC is 2.5V or higher. At VCC <2.5V (e.g., 1.7V–2.4V), the maximum clock rate is limited to 100 kHz to ensure reliable timing margins. This dual-speed capability allows flexible system design: high-throughput parameter updates at 3.3V/5V, and guaranteed operation in 1.8V battery-backed subsystems at reduced speed.

Does the 24AA64F-I/MS require an external pull-up resistor on the SDA line?

Yes - the SDA pin on the 24AA64F-I/MS is open-drain and requires an external pull-up resistor to VCC. Recommended values are 10 kΩ for 100 kHz operation and 2 kΩ for 400 kHz, per Microchip's DS22154B specification. The resistor value balances rise time (to meet I²C timing requirements) against power consumption during low states; improper sizing can cause communication failures or excessive standby current.