Microchip Technology 24LC32AFT-E/OT

Overview

24LC32AFT-E/OT from Microchip Technology Inc. is a 32 Kbit I²C-compatible serial EEPROM organized as 4K × 8-bit memory, operating from 2.5V to 5.5V with industrial-temperature (−40°C to +85°C) rating and 400 kHz max clock frequency. It features hardware write-protection for the upper quarter array (C00h–FFFh), 32-byte page write buffer, and Schmitt-trigger inputs for noise immunity-used in embedded system configuration storage, sensor calibration data retention, and power-meter firmware parameter backup.

For engineers reviewing the 24LC32AFT-E/OT datasheet, 24LC32AFT-E/OT pinout, 24LC32AFT-E/OT application, or 24LC32AFT-E/OT equivalent, key selection criteria include VCC min (2.5V), WP-enabled quarter-array protection, 5 ms max page write time, I²C bus compatibility up to 400 kHz, and SOT-23-5 package footprint constraints.

Technical Context

The 24LC32AFT-E/OT implements a two-wire I²C slave interface with fixed 7-bit device address prefix '1010' and three programmable chip-select bits (A2–A0), though those pins are omitted in the SOT-23-5 package-making its address fixed at 1010000b (0x50). It uses on-chip charge pump for EEPROM programming and supports byte-write and page-write (up to 32 bytes) with self-timed erase/write cycles.

Its internal architecture includes a 32-byte page latch, address pointer auto-increment logic, and dedicated write-protect circuitry sampling the WP pin at the STOP bit of each write command. The SOT-23-5 variant excludes A0/A1/A2 pins and supports only single-device operation per bus segment, with pinout optimized for space-constrained PCB layouts.

Key Specifications

Pinout & Package

24LC32AFT-E/OT is supplied in Pb-free, RoHS-compliant 5-lead SOT-23 package (1.6 mm × 2.8 mm footprint), optimized for high-density PCBs. Unlike 8-pin variants, it omits A0/A1/A2 address pins-fixing its I²C slave address at 0x50 and limiting bus topology to one device per segment.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24AA32AFT-E/OT and AT24C32D-SSHM-T, the 24LC32AFT-E/OT provides deterministic hardware write protection for critical memory regions and guaranteed 400 kHz timing at 2.5V-making it optimal for industrial control and metering where robustness outweighs sub-2.5V operation.

Availability

24LC32AFT-E/OT is available at Aetrix Electronics and suitable for industrial sensor nodes, smart energy meters, and medical diagnostic devices requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for 24LC32AFT-E/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 microcontrollers, analog components, and nonvolatile memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 24LC32AFT-E/OT belongs to Microchip's 24XX32AF family of I²C serial EEPROMs, engineered for reliable, low-power data storage in space-constrained embedded systems across industrial, automotive, and medical applications.

FAQ

What is the I²C slave address of the 24LC32AFT-E/OT?

The 24LC32AFT-E/OT has a fixed 7-bit I²C slave address of 0x50 (1010000b) because its SOT-23-5 package omits the A0, A1, and A2 address pins. This address is used for both read and write operations, with the R/W bit determining direction. No external address configuration is possible on this variant.

Does the 24LC32AFT-E/OT support 100 kHz and 400 kHz I²C speeds simultaneously?

Yes-the 24LC32AFT-E/OT supports both 100 kHz and 400 kHz clock frequencies depending on VCC level: 400 kHz is guaranteed at VCC ≥ 2.5V, while 100 kHz operation is specified for VCC < 2.5V. Its AC timing parameters (e.g., THIGH, TLOW) are explicitly defined for both modes in the datasheet.

How does the hardware write-protect feature work on the 24LC32AFT-E/OT?

When the WP pin of the 24LC32AFT-E/OT is tied to VCC, writes to memory addresses C00h–FFFh (upper 8 Kbit) are blocked at the silicon level; reads remain fully functional. The protection is sampled at the STOP bit of each write command, making it immune to transient WP glitches during active transfers.

Can the 24LC32AFT-E/OT be used in automotive applications?

The 24LC32AFT-E/OT is rated for Industrial temperature (−40°C to +85°C), not Automotive (−40°C to +125°C). For automotive body control or infotainment modules requiring extended temperature operation, Microchip's 24LC32AFE/OT (E-temp grade) is the qualified alternative-identical functionality with validated performance at 125°C ambient.

What is the maximum page write size supported by the 24LC32AFT-E/OT?

The 24LC32AFT-E/OT supports a 32-byte page write buffer. Writing more than 32 bytes before issuing a STOP condition causes the address counter to wrap within the current page, overwriting earlier bytes. Page boundaries align to 32-byte intervals (e.g., 000h–01Fh, 020h–03Fh), so software must enforce boundary checks.