Microchip Technology 24AA32AT-I/OT

Overview

24AA32AT-I/OT from Microchip Technology is a 32-Kbit I²C-compatible serial EEPROM organized as 4K × 8-bit, operating from 1.7V to 5.5V with 400 kHz max clock frequency (100 kHz below 2.5V), 5 ms max page write time, and industrial temperature range (–40°C to +85°C). It features hardware write-protection via the WP pin, Schmitt-trigger inputs for noise immunity, and 32-byte page write buffer - deployed in embedded system configuration storage, sensor calibration data retention, and power-meter firmware parameter backup.

For engineers reviewing the 24AA32AT-I/OT datasheet, 24AA32AT-I/OT pinout, 24AA32AT-I/OT application, or 24AA32AT-I/OT equivalent, key selection considerations include its 1.7V low-voltage operation, I²C bus compatibility up to eight devices per bus, 1 µA standby current, and TSSOP-8 packaging with exposed pad option - critical for space-constrained industrial controllers and battery-powered IoT nodes.

Technical Context

The 24AA32AT-I/OT implements a two-wire I²C interface with fixed 4-bit control code (1010b) and 3-bit chip address (A2–A0), enabling up to eight devices on one bus. Its internal address pointer supports current-address, random, and sequential read modes, while page write logic enforces 32-byte boundaries with automatic wraparound on overflow.

Write protection is controlled solely by the WP pin state at the Stop bit of each write command; tying WP to VCC disables all writes but permits reads. The device uses an internal HV generator for EEPROM programming and incorporates slope-controlled outputs to suppress ground bounce during SDA transitions.

Key Specifications

Pinout & Package

24AA32AT-I/OT is supplied in an 8-lead TSSOP package (3.0 mm × 4.4 mm body, 0.65 mm pitch) with standard pinout and optional exposed thermal pad connected to VSS or left floating.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24AA32AT-I/OT, the 24LC32AT-I/OT excludes 1.7–2.49V operation but shares identical footprint and software interface, while the AT24C32D-SSHM-T offers higher clock tolerance and broader vendor support - making it preferable for high-volume consumer electronics where timing headroom and supply chain resilience are prioritized.

Availability

24AA32AT-I/OT is available at Aetrix Electronics and suitable for industrial sensor calibration storage, smart meter configuration backup, and medical diagnostic equipment settings requiring stable component supply across multi-year production cycles.

Supply support for 24AA32AT-I/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 24AA32A family was designed specifically for low-voltage, low-power embedded systems requiring reliable nonvolatile storage - targeting industrial automation, automotive subsystems, and portable medical devices where extended temperature operation and robust I²C interoperability are mandatory.

FAQ

What is the minimum operating voltage for the 24AA32AT-I/OT?

The 24AA32AT-I/OT operates down to 1.7V DC, enabling direct interfacing with 1.8V logic families and ultra-low-power microcontrollers. This specification is confirmed in the Electrical Characteristics table (Param D10) under Industrial temperature range, where ICCS standby current remains ≤1 µA at 1.7V. Below 2.5V, maximum clock frequency is reduced to 100 kHz to maintain timing margins.

Does the 24AA32AT-I/OT support multiple devices on the same I²C bus?

Yes, the 24AA32AT-I/OT supports up to eight devices on a single I²C bus using its three hardware address pins (A0, A1, A2). Each combination of these pins sets a unique 3-bit chip address that, when combined with the fixed 4-bit control code (1010b), forms a 7-bit client address. This allows contiguous 256-Kbit addressing across multiple 24AA32AT-I/OT units without software address translation.

How does the write-protect (WP) pin function on the 24AA32AT-I/OT?

The WP pin on the 24AA32AT-I/OT is sampled at the Stop bit of each write command: when tied to VCC, all write operations (byte and page) are inhibited while read operations remain fully functional. This hardware-level protection operates independently of firmware state, preventing accidental overwrites during power transients or software faults. The pin has no effect on read cycles or acknowledge polling behavior.

What is the page write capability of the 24AA32AT-I/OT?

The 24AA32AT-I/OT features a 32-byte page write buffer, allowing up to 32 bytes to be loaded into the buffer before initiating an internal self-timed write cycle upon receipt of the Stop condition. Page boundaries align to 32-byte intervals (addresses 0x000–0x01F, 0x020–0x03F, etc.), and crossing a boundary causes wraparound within the current page - requiring host firmware to manage alignment for reliable multi-byte writes.

Is the 24AA32AT-I/OT RoHS compliant and qualified for automotive use?

Yes, the 24AA32AT-I/OT is RoHS compliant per EU Directive 2011/65/EU and qualified to AEC-Q100 Grade 3 (–40°C to +85°C), making it suitable for under-hood and cabin applications in automotive ECUs. Its qualification includes stress testing for temperature cycling, humidity bias, and ESD - documented in Microchip's AEC-Q100 certification report for the 24AA32A family.