Microchip Technology 24AA32AFT-I/ST

Overview

24AA32AFT-I/ST from Microchip Technology Inc. is a 32 Kbit I²C-compatible serial EEPROM organized as 4K × 8-bit memory, operating from 1.7V to 5.5V with industrial temperature range (–40°C to +85°C), 400 μA max read current, 1 μA max standby current, and hardware write-protect for upper 1/4 array (C00h–FFFh). It supports cascading up to eight devices on one bus and is used in low-power embedded systems requiring nonvolatile configuration storage.

For engineers reviewing the 24AA32AFT-I/ST datasheet, 24AA32AFT-I/ST pinout, 24AA32AFT-I/ST application, or 24AA32AFT-I/ST equivalent, key selection criteria include I²C clock compatibility (100/400 kHz), page write buffer size (32 bytes), write-protect granularity, low-voltage operation down to 1.7V, and TSSOP-8 package footprint suitability for space-constrained PCB layouts.

Technical Context

The 24AA32AFT-I/ST implements a two-wire I²C interface with Schmitt-trigger inputs and slew-rate-controlled outputs to suppress noise and eliminate ground bounce. Its internal address counter supports current-address, random, and sequential read modes, while the 32-byte page write buffer enables efficient burst writes within physical page boundaries (0–31, 32–63, etc.).

Write protection is implemented via the WP pin, which-when tied to VCC-disables writes only to addresses C00h–FFFh (upper 8 Kbits); all other addresses remain writable. The device uses self-timed erase/write cycles with 5 ms maximum page write time and supports acknowledge polling to detect write completion without fixed delays.

Key Specifications

Pinout & Package

24AA32AFT-I/ST is supplied in an 8-lead TSSOP package (3.0 mm × 4.4 mm, 0.65 mm pitch), optimized for automated assembly and high-density PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24AA32AFT-I/ST, the 24LC32AFT-I/ST lacks 1.7V support but offers identical industrial temp rating and packaging, while the AT24C32D-SSHM-T trades quarter-array WP for 1 MHz I²C and different endurance specs-making 24AA32AFT-I/ST optimal for ultra-low-voltage, write-granularity-critical designs.

Availability

24AA32AFT-I/ST is available at Aetrix Electronics and suitable for smart metering, industrial PLCs, medical diagnostics, and automotive body control modules requiring stable component supply across extended production lifecycles.

Supply support for 24AA32AFT-I/ST 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 company specializing in microcontrollers, analog devices, and memory products for embedded control applications.

The 24AAxxA family was designed specifically for low-power, I²C-based nonvolatile data storage in space- and energy-constrained systems such as portable instrumentation and battery-operated edge nodes.

FAQ

What is the minimum operating voltage for the 24AA32AFT-I/ST?

The 24AA32AFT-I/ST operates down to 1.7V, enabling direct integration with 1.8V logic families and single-cell Li-ion or Li-SOCl₂ battery systems without voltage translation. This specification is confirmed in the DC Characteristics table (Parameter D11, ICCS) of DS22184A, where standby current is guaranteed at 1.7V. Operation below 1.7V is not characterized and may result in unreliable read/write behavior or loss of I²C communication.

Does the 24AA32AFT-I/ST support page write operations, and what is the buffer size?

Yes, the 24AA32AFT-I/ST supports page write operations with a 32-byte buffer, allowing up to 32 bytes to be written in a single I²C transaction. Physical page boundaries align to 32-byte increments (e.g., 0x000–0x01F, 0x020–0x03F), and crossing a boundary causes wraparound within the current page. This is documented in Section 6.2 (Page Write) and Figure 6-2 of DS22184A, and directly impacts firmware design for efficient configuration storage.

How does the write-protect (WP) pin function on the 24AA32AFT-I/ST?

The WP pin on the 24AA32AFT-I/ST enables hardware-level protection of the upper 1/4 memory array (addresses C00h–FFFh). When WP is tied to VCC, writes to that region are inhibited while reads remain fully functional; tying WP to VSS enables full-array writes. The pin state is sampled at the Stop condition of each write command, as specified in Section 6.3 and Figure 4-1 of DS22184A, making it effective for safeguarding bootloader or security keys.

What package type is used for the 24AA32AFT-I/ST, and what are its key mechanical dimensions?

The 24AA32AFT-I/ST uses an 8-lead TSSOP package (3.0 mm × 4.4 mm body, 0.65 mm lead pitch), as confirmed in the Package Types diagram (DS22184A, page 1) and Package Marking Information (page 14). This surface-mount package supports automated pick-and-place assembly and provides thermal and electrical performance suitable for industrial ambient temperatures up to +85°C, with JEDEC-standard footprint compatibility.

Can multiple 24AA32AFT-I/ST devices share the same I²C bus, and how is addressing managed?

Yes, up to eight 24AA32AFT-I/ST devices can share one I²C bus using hardwired A0, A1, and A2 pins to configure unique 3-bit chip addresses. The base slave address is 1010b, followed by A2–A0 bits and R/W, yielding addresses from 1010000b to 1010111b. This cascading capability is explicitly stated in the Features section and Device Selection Table of DS22184A, enabling scalable memory expansion to 256 Kbits without additional address decoding logic.