Microchip Technology 24LC32AT-E/OT

Overview

24LC32AT-E/OT from Microchip Technology is a 32-Kbit I²C-compatible serial EEPROM organized as 4K × 8-bit memory, operating from 2.5V to 5.5V with 400 kHz max clock frequency and industrial-extended temperature range (–40°C to +125°C). It features hardware write-protection via the WP pin, 32-byte page write buffer, and Schmitt-trigger inputs for noise immunity - deployed in automotive body control modules, industrial sensor nodes, and embedded system configuration storage.

For engineers reviewing the 24LC32AT-E/OT datasheet, 24LC32AT-E/OT pinout, 24LC32AT-E/OT application, or 24LC32AT-E/OT equivalent, key selection criteria include its 2.5V minimum VCC, E-temp qualification, MSOP-8 package footprint, and I²C bus timing compliance at both 100 kHz and 400 kHz across voltage and temperature ranges.

Technical Context

The 24LC32AT-E/OT implements a two-wire I²C interface with open-drain SDA/SCL pins, internal address pointer, and automatic page-write wraparound handling. Its architecture supports up to eight devices on one bus using A0–A2 chip-select bits, with device addressing based on the fixed 4-bit control code '1010' followed by three address bits and R/W bit.

Write operations are self-timed with maximum 5 ms cycle time; read modes include current-address, random, and sequential reads. Acknowledge polling is supported to detect write completion, and the WP pin enables hardware-level array protection - sampled only at the Stop bit of each write command.

Key Specifications

Pinout & Package

24LC32AT-E/OT is packaged in an 8-lead MSOP (Micro Small Outline Package) with 3 mm × 3 mm body and 0.65 mm pitch. The exposed pad is not electrically connected and may be left floating or tied to VSS per layout best practice.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24LC32AT-E/OT, the 24AA32AT-I/OT trades extended temperature support for lower-voltage operation, while the AT24C32D-SSHM-T offers broader voltage range but omits automotive qualification and hardware write-protection assurance - making 24LC32AT-E/OT the sole choice for safety-critical, high-ambient deployments.

Availability

24LC32AT-E/OT is available at Aetrix Electronics and suitable for automotive BCU modules, industrial sensor calibration systems, and medical infusion pump designs requiring stable component supply with guaranteed long-term availability and traceable sourcing.

Supply support for 24LC32AT-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 devices, and memory solutions, serving automotive, industrial, and communications markets with vertically integrated silicon and development tools.

The 24LC32A family delivers I²C EEPROMs optimized for automotive-grade reliability and extended-temperature operation, targeting configuration storage in harsh-environment electronic control units where data integrity and longevity are mission-critical.

FAQ

What is the minimum operating voltage for the 24LC32AT-E/OT?

The 24LC32AT-E/OT operates from 2.5V to 5.5V. Unlike the 24AA32A variant, it does not support voltages below 2.5V - this ensures stable I²C timing and EEPROM programming margins across its –40°C to +125°C extended temperature range. Operation below 2.5V risks incomplete writes or timing violations.

Does the 24LC32AT-E/OT support page write operations, and what is the buffer size?

Yes, the 24LC32AT-E/OT supports page write with a 32-byte buffer. This allows up to 32 bytes to be loaded into the on-chip latch before initiating the internal 5 ms write cycle. Crossing physical page boundaries (every 32-byte aligned address) causes wraparound - software must manage alignment to avoid unintended overwrites.

How is write protection implemented on the 24LC32AT-E/OT?

Write protection on the 24LC32AT-E/OT is controlled by the WP pin: when tied to VCC, all write operations (byte and page) are inhibited while reads remain fully functional. The pin is sampled only at the Stop bit of each write command - toggling WP mid-cycle has no effect, ensuring deterministic behavior during firmware updates.

Is the 24LC32AT-E/OT AEC-Q100 qualified, and for which grade?

Yes, the 24LC32AT-E/OT is AEC-Q100 qualified for Grade 1 (–40°C to +125°C), covering full automotive under-hood and chassis applications. This qualification includes stress testing for temperature cycling, HTOL, ESD, and AC/DC parametric stability - verified per Rev H requirements.

What package type is used for the 24LC32AT-E/OT, and what are its key mechanical dimensions?

The 24LC32AT-E/OT uses an 8-lead MSOP package (3 mm × 3 mm body, 0.65 mm pitch). Key dimensions include 0.80 mm nominal height, 0.40 mm terminal width, and 3.00 mm overall length. The exposed pad is unconnected and may be left floating or grounded for thermal relief per PCB design guidelines.