Microchip Technology 24LC32AX-I/ST

Overview

24LC32AX-I/ST 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 (≥2.5V), 1 μA standby current (I-temp), and hardware write-protection via WP pin. It supports cascading up to eight devices on one bus and is used in industrial control systems for nonvolatile parameter storage.

For engineers reviewing the 24LC32AX-I/ST datasheet, 24LC32AX-I/ST pinout, 24LC32AX-I/ST application, or 24LC32AX-I/ST equivalent, key selection criteria include VCC range compatibility (2.5–5.5V), I²C timing compliance at 400 kHz, industrial temperature rating (−40°C to +85°C), and TSSOP-8 package footprint constraints.

Technical Context

The 24LC32AX-I/ST implements a slave-only I²C interface with fixed 7-bit address prefix '1010' and three programmable chip-select bits (A2–A0), enabling up to eight devices per bus. Its internal architecture includes a 32-byte page write buffer, Schmitt-triggered SDA/SCL inputs for noise immunity, and slope-controlled outputs to suppress ground bounce.

Write operations are self-timed (5 ms max byte/page cycle) and support byte or page writes; write protection is controlled by the WP pin tied to VCC (enabled) or VSS (disabled). Acknowledge polling is supported to detect write completion without fixed delays.

Key Specifications

Pinout & Package

24LC32AX-I/ST is supplied in an 8-lead TSSOP package (4.4 mm body width, JEDEC MO-153), with gull-wing leads and standard 0.65 mm pitch. Pin 1 is marked by a dot or beveled corner; orientation follows standard TSSOP pin 1 indicator (top-left when notch up).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24LC32AT-I/SM and AT24C32D-SSHM-T, the 24LC32AX-I/ST delivers optimal balance of industrial temperature validation, compact TSSOP-8 footprint, and proven interoperability with Microchip's ecosystem - making it ideal for space-constrained industrial controllers where automotive qualification is unnecessary.

Availability

24LC32AX-I/ST is available at Aetrix Electronics and suitable for industrial automation, smart metering, and medical device manufacturing requiring stable component supply, long-term obsolescence management, and consistent lot-to-lot parametric performance.

Supply support for 24LC32AX-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, and Flash-IP solutions, headquartered in Chandler, Arizona, with global design and manufacturing infrastructure.

The 24LC32A family was designed specifically for low-power, high-reliability nonvolatile data storage in industrial and commercial systems - emphasizing I²C simplicity, write endurance, and robustness across extended temperature ranges.

FAQ

What is the maximum I²C clock frequency supported by the 24LC32AX-I/ST?

The 24LC32AX-I/ST supports up to 400 kHz I²C clock frequency when VCC is 2.5V or higher. It does not support the 100 kHz low-voltage mode below 2.5V - that capability is exclusive to the 24AA32A variant. This makes the 24LC32AX-I/ST suitable for systems using standard 3.3V or 5V I²C buses where timing margins allow 400 kHz operation.

Does the 24LC32AX-I/ST support page write operations, and what is the buffer size?

Yes, the 24LC32AX-I/ST supports page write operations with a 32-byte buffer. This allows up to 32 bytes to be loaded into the on-chip latch before initiating the internal write cycle, reducing I²C transaction overhead. Page boundaries align to 32-byte increments (e.g., addresses 0x000–0x01F), and crossing boundaries causes wraparound - software must enforce alignment.

How is write protection implemented on the 24LC32AX-I/ST?

Write protection on the 24LC32AX-I/ST is controlled exclusively by the WP (Write-Protect) pin. When WP is tied to VCC, all write operations (byte and page) are inhibited while reads remain fully functional. When WP is tied to VSS, full read/write access is enabled. The pin state is sampled at the Stop condition of each write command - toggling WP mid-cycle has no effect.

What package type is used for the 24LC32AX-I/ST, and what are its key mechanical dimensions?

The 24LC32AX-I/ST uses an 8-lead TSSOP package (JEDEC MO-153), measuring 4.4 mm × 3.0 mm × 1.1 mm (L × W × H) with 0.65 mm lead pitch. It features gull-wing leads and a standard pin 1 marker (dot or bevel). This compact footprint supports high-density PCB layouts while maintaining hand-soldering feasibility.

Can multiple 24LC32AX-I/ST devices share the same I²C bus, and how is addressing managed?

Yes, up to eight 24LC32AX-I/ST devices can share one I²C bus using hardware address lines A0, A1, and A2. Each device's 7-bit slave address begins with '1010', followed by the logic levels on A2–A0 (e.g., A2=0, A1=1, A0=0 yields address 0x54). All three pins must be hardwired to VSS or VCC - floating connections cause undefined behavior.