Microchip Technology 24LC32AT-I/ST

Overview

24LC32AT-I/ST from Microchip Technology is a 32-Kbit I²C serial EEPROM organized as 4K × 8-bit memory, operating from 2.5V to 5.5V with 400 kHz clock support, 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-used in embedded system configuration storage, sensor calibration data retention, and firmware parameter backup.

For engineers reviewing the 24LC32AT-I/ST datasheet, 24LC32AT-I/ST pinout, 24LC32AT-I/ST application, or 24LC32AT-I/ST equivalent, key selection criteria include V_CC compatibility (2.5–5.5V), I²C bus timing at 400 kHz, WP-controlled write lock, SOIC-8 package footprint, and endurance (>1 million cycles) for field-updatable systems requiring long-term nonvolatile storage.

Technical Context

The 24LC32AT-I/ST implements a two-wire I²C-compatible interface with open-drain SDA/SCL pins, internal address pointer for sequential reads, and hardware-based write protection controlled by the WP pin sampled at Stop condition. Its architecture supports up to eight devices on one bus using A0–A2 address inputs.

It uses low-power CMOS technology with typical active current of 1 mA and standby current of 1 µA, integrated Schmitt-trigger inputs (V_HYS = 0.05 V_CC) and slope-controlled outputs to suppress ground bounce-enabling reliable operation in electrically noisy industrial environments.

Key Specifications

Pinout & Package

24LC32AT-I/ST is packaged in an 8-lead SOIC (Small Outline Integrated Circuit) with 1.27 mm pitch, 3.90 mm body width, and JEDEC MS-012AC compliant footprint. The package is RoHS-compliant and rated for industrial temperature operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24LC32AT-I/ST, the 24AA32AT-I/ST extends voltage range downward but sacrifices automotive qualification, while the AT24C32D-SSHM-T trades write speed and qualification for lower cost-making 24LC32AT-I/ST optimal for industrial and automotive applications demanding guaranteed 2.5V+ operation and AEC-Q100 compliance.

Availability

24LC32AT-I/ST is available at Aetrix Electronics and suitable for industrial sensor nodes, medical calibration storage, smart energy meters, and automotive body control modules requiring stable component supply, long-term lifecycle support, and traceable sourcing.

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

The 24LC32A family delivers cost-effective, low-power I²C EEPROMs optimized for configuration storage and parameter retention in space-constrained, thermally demanding embedded systems.

FAQ

What is the minimum V_CC required for reliable operation of the 24LC32AT-I/ST?

The 24LC32AT-I/ST requires a minimum V_CC of 2.5V for full specification compliance-including 400 kHz I²C operation and guaranteed write functionality. Below 2.5V, clock frequency is limited to 100 kHz, and some AC parameters degrade. The 24LC32AT-I/ST is not rated for operation at 1.7V like the 24AA32A variant.

Does the 24LC32AT-I/ST support page write operations, and what is the maximum buffer size?

Yes, the 24LC32AT-I/ST supports page write operations with a 32-byte internal buffer. This allows up to 32 bytes to be loaded into the buffer and written to memory in a single self-timed cycle (≤5 ms). Writing across a 32-byte page boundary causes wraparound within the same page-not automatic advancement to the next page.

How does the WP pin function on the 24LC32AT-I/ST, and when is it sampled?

The WP (Write-Protect) pin on the 24LC32AT-I/ST is sampled at the Stop condition of each I²C write command. When tied to VCC, all write operations (byte and page) are inhibited while read operations remain fully functional. Toggling WP during an ongoing write cycle has no effect-the state at Stop determines protection for that command.

Is the 24LC32AT-I/ST AEC-Q100 qualified, and which grade applies?

Yes, the 24LC32AT-I/ST is AEC-Q100 qualified for Grade 3 (–40°C to +85°C), matching its industrial temperature rating. This qualification covers stress testing for automotive use cases including thermal cycling, humidity bias, and ESD-validating suitability for body electronics and infotainment subsystems.

What package type and footprint does the 24LC32AT-I/ST use, and is it lead-free?

The 24LC32AT-I/ST uses an 8-lead SOIC package (3.90 mm body width, 1.27 mm pitch) with JEDEC MS-012AC outline. It is RoHS-compliant and lead-free, with matte tin (Sn) termination. The land pattern requires 1.45 mm pad length, 0.45 mm pad width, and 4.40 mm center-to-center spacing between outer pads.