Microchip Technology 24LC32A-E/SM

Overview

24LC32A-E/SM 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 400 kHz max clock frequency and industrial/extended temperature range (–40°C to +125°C). It features hardware write-protection, 32-byte page write buffer, and Schmitt-trigger inputs for noise immunity - deployed in automotive body control modules, industrial sensor calibration storage, and medical device configuration retention.

For engineers reviewing the 24LC32A-E/SM datasheet, 24LC32A-E/SM pinout, 24LC32A-E/SM application, or 24LC32A-E/SM equivalent, key selection criteria include VCC min/max compatibility, WP pin behavior under fault conditions, page boundary handling in firmware, and extended-temperature qualification per AEC-Q100 Grade 1.

Technical Context

The 24LC32A-E/SM 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 auto-increments during sequential reads and supports current-address, random, and sequential read modes.

Write operations are self-timed with maximum 5 ms cycle time; page writes buffer up to 32 bytes within a single 32-byte physical page boundary. The WP pin samples at the Stop bit to enable/disable array write access, and acknowledge polling is required to detect write completion.

Key Specifications

Pinout & Package

24LC32A-E/SM is packaged in an 8-lead MSOP (3×3 mm body, micro small outline package) with gull-wing leads and exposed pad option. Pin 1 is marked by notch or bevel; package conforms to JEDEC MO-187AA and Microchip drawing C04-111-MS Rev F.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24LC32AT-I/SM, the 24LC32A-E/SM adds extended temperature operation and AEC-Q100 qualification at no pinout or firmware change; versus AT24C32D-SSHM-T, it trades raw speed and low-voltage flexibility for certified automotive robustness and long-term data integrity under thermal stress.

Availability

24LC32A-E/SM is available at Aetrix Electronics and suitable for automotive body electronics, industrial sensor calibration, and medical device configuration storage requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 24LC32A-E/SM 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 24LC32A-E/SM belongs to Microchip's serial EEPROM product line, engineered specifically for reliable, low-power, I²C-based configuration and calibration data storage in automotive, industrial, and medical applications demanding extended temperature operation and AEC-Q100 compliance.

FAQ

What is the minimum VCC voltage required for reliable operation of the 24LC32A-E/SM?

The 24LC32A-E/SM requires a minimum VCC of 2.5V for guaranteed operation across its full –40°C to +125°C extended temperature range. Unlike the 24AA32A variant, it does not support 1.7V operation. Operating below 2.5V may result in undefined behavior, failed writes, or incomplete acknowledge polling - always verify supply stability under worst-case load and temperature conditions for 24LC32A-E/SM.

How does the WP pin function during active I²C communication on the 24LC32A-E/SM?

The WP pin on the 24LC32A-E/SM is sampled only at the Stop condition of each write command - toggling WP during ongoing SDA/SCL activity has no effect. When tied to VCC, all write operations (byte and page) are inhibited while reads remain fully functional. This behavior enables safe runtime protection without disrupting host polling or read sequences, making it ideal for safeguarding critical configuration data in 24LC32A-E/SM deployments.

Can the 24LC32A-E/SM perform page writes across physical page boundaries?

No. The 24LC32A-E/SM restricts page writes to a single 32-byte physical page - defined by address boundaries aligned to multiples of 32 (e.g., 0x000–0x01F, 0x020–0x03F). Attempting to write across a boundary causes automatic wraparound within the current page, overwriting earlier bytes. Firmware must explicitly check address alignment before initiating page writes to ensure data integrity in 24LC32A-E/SM applications.

What is the maximum I²C clock frequency supported by the 24LC32A-E/SM at 3.3V VCC?

At 3.3V VCC, the 24LC32A-E/SM supports a maximum I²C clock frequency of 400 kHz, consistent with Fast-mode I²C specification. AC timing parameters including THIGH (≥600 ns), TLOW (≥1300 ns), and TR/TF (≤300 ns) are fully met at this voltage and speed. Exceeding 400 kHz risks setup/hold violations and unreliable acknowledge generation - always validate signal integrity with scope measurements on actual 24LC32A-E/SM hardware.

Is the 24LC32A-E/SM qualified for automotive applications, and what level of qualification does it hold?

Yes, the 24LC32A-E/SM is AEC-Q100 qualified for automotive use at Grade 1 (–40°C to +125°C ambient), covering stress tests including HTOL, TC, ESD, and AC/DC parametric verification. This qualification confirms suitability for powertrain-adjacent, chassis, and body electronics - not just passenger compartment modules. Full test reports and certificate numbers are available upon request for 24LC32A-E/SM automotive program validation.