Microchip Technology 24AA32AXT-I/ST

Overview

24AA32AXT-I/ST from Microchip Technology Inc. is a 32 Kbit I²C-compatible serial EEPROM organized as 4K × 8-bit memory, operating from 1.8V to 5.5V with 1 mA typical active current and 1 μA max standby current (I-temp). It features hardware write-protection via the WP pin, Schmitt-trigger inputs for noise immunity, and supports up to eight devices on one bus using A0–A2 address pins. Used in low-power embedded systems for parameter storage and firmware configuration.

For engineers reviewing the 24AA32AXT-I/ST datasheet, 24AA32AXT-I/ST pinout, 24AA32AXT-I/ST application, or 24AA32AXT-I/ST equivalent, key selection criteria include V_CC range (1.8–5.5V), 400 kHz max clock (≥2.5V), industrial temperature rating (−40°C to +85°C), TSSOP-8 package footprint, and page-write capability (up to 32 bytes).

Technical Context

The 24AA32AXT-I/ST implements a slave-only I²C interface with fixed 7-bit device address prefix '1010' and three programmable chip-select bits (A2–A0), enabling multi-device bus topology. Its internal architecture includes a 32-byte page latch, HV generator for EEPROM programming, and address pointer auto-increment logic for sequential read/write operations.

It uses Schmitt-trigger inputs on SDA/SCL with 0.05 V_CC hysteresis and slope-controlled outputs to suppress ground bounce. Write cycles are self-timed (5 ms max), and acknowledge polling is supported to detect completion without fixed delays.

Key Specifications

Pinout & Package

24AA32AXT-I/ST is housed in an 8-lead TSSOP package (4.4 mm × 3.0 mm, 0.65 mm pitch) with exposed pad not electrically connected. Pin 1 is marked by a dot or notch; orientation follows standard JEDEC MO-153 outline.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24LC32AT-I/ST, the 24AA32AXT-I/ST enables true 1.8V operation and eight-device addressing; versus AT24C32D-SSHM-T, it offers higher bus scalability and Microchip's validated industrial qualification, though at slightly narrower voltage headroom below 1.8V.

Availability

24AA32AXT-I/ST is available at Aetrix Electronics and suitable for smart metering, industrial PLC configuration, and automotive body control modules requiring stable component supply across extended product lifecycles.

Supply support for 24AA32AXT-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 leading provider of microcontrollers, analog devices, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 24AA32A family is designed for ultra-low-power, high-reliability nonvolatile data storage in space-constrained embedded systems where I²C interface simplicity and industrial temperature resilience are critical.

FAQ

What is the maximum I²C clock frequency supported by the 24AA32AXT-I/ST?

The 24AA32AXT-I/ST supports up to 400 kHz when V_CC is 2.5V or higher. At 1.8V ≤ V_CC < 2.5V, the maximum clock frequency is 100 kHz. These limits are defined by internal timing margins and ensure reliable setup/hold times across the full industrial temperature range. The 24AA32AXT-I/ST does not require external clock dividers or protocol adaptation to meet these specifications.

How does the WP pin function on the 24AA32AXT-I/ST?

The WP (Write-Protect) pin on the 24AA32AXT-I/ST is an active-high input that disables all write operations-including byte write, page write, and write-enable commands-when pulled to V_CC. When tied to V_SS, writes are fully enabled. The pin state is sampled at the Stop condition of each write command, so toggling WP mid-operation has no effect. This hardware-level protection is independent of I²C command flow and applies to the entire 32 Kbit memory array.

Can multiple 24AA32AXT-I/ST devices share the same I²C bus?

Yes, up to eight 24AA32AXT-I/ST devices can operate on the same I²C bus using the A0, A1, and A2 address pins to configure unique 7-bit slave addresses. Each combination of A2–A0 sets the three LSBs of the base address '1010xxx', allowing distinct addressing without software arbitration. No additional hardware or bus isolation is required, provided pull-up resistors are sized for total bus capacitance.

What is the page write capability of the 24AA32AXT-I/ST?

The 24AA32AXT-I/ST includes a 32-byte page write buffer that accepts up to 32 consecutive bytes in a single I²C transaction before initiating the internal 5 ms write cycle. Writes crossing physical page boundaries (every 32 bytes, aligned to 0x00, 0x20, etc.) wrap around within the current page rather than advancing to the next, so firmware must enforce boundary alignment. This feature reduces I²C overhead by up to 31× compared to individual byte writes.

Is the 24AA32AXT-I/ST compatible with standard I²C protocol implementations?

Yes, the 24AA32AXT-I/ST is fully compliant with the standard two-wire I²C bus specification, including Start/Stop condition generation, 7-bit addressing, ACK/NACK handshaking, and clock stretching during internal write cycles. It responds to the standard control code '1010' prefix and supports repeated Start conditions. No custom drivers or protocol extensions are needed-standard HAL or OS I²C APIs work out-of-the-box with the 24AA32AXT-I/ST.