Microchip Technology 24LC32AXT-I/ST

Overview

24LC32AXT-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) and industrial temperature range (–40°C to +85°C). It features hardware write-protection via 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 24LC32AXT-I/ST datasheet, 24LC32AXT-I/ST pinout, 24LC32AXT-I/ST application, or 24LC32AXT-I/ST equivalent, key selection criteria include VCC voltage compatibility (2.5–5.5V), I²C bus timing compliance at 400 kHz, WP-controlled write protection behavior, and TSSOP-8 package footprint constraints for PCB layout.

Technical Context

The 24LC32AXT-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 on one bus. Its internal address pointer auto-increments during sequential reads and wraps from 0xFFF to 0x000.

Write operations are self-timed with 5 ms typical byte/page cycle time; acknowledge polling is supported to detect completion. The device uses on-chip charge pump for EEPROM programming and includes input hysteresis (0.05×VCC) and output slope control to suppress ground bounce and EMI.

Key Specifications

Pinout & Package

24LC32AXT-I/ST is housed in an 8-lead Thin Shrink Small Outline Package (TSSOP) with 0.65 mm lead pitch and 4.4 mm body width. Pin 1 is marked by a dot or beveled corner; orientation follows standard TSSOP pin 1 indicator (top-left when notch faces up).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24LC32AXT-I/ST, the 24LC32AT-I/ST offers identical functionality with minor packaging variance, while AT24C32D-SSHM-T trades TSSOP-8 compatibility and guaranteed WP noise immunity for wider VCC range and higher clock rate - requiring board redesign and timing revalidation.

Availability

24LC32AXT-I/ST is available at Aetrix Electronics and suitable for industrial sensor nodes, medical device calibration storage, and automotive body control modules requiring stable component supply across extended product lifecycles.

Supply support for 24LC32AXT-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, headquartered in Chandler, Arizona, with global design and manufacturing infrastructure.

The 24LC32A family was designed for cost-sensitive, low-power embedded systems requiring reliable nonvolatile storage - emphasizing I²C simplicity, industrial temperature resilience, and hardware-level data protection.

FAQ

What is the minimum VCC voltage required for reliable operation of the 24LC32AXT-I/ST?

The 24LC32AXT-I/ST requires a minimum VCC of 2.5V for guaranteed operation, as specified in the Device Selection Table and Electrical Characteristics section. Unlike the 24AA32A variant, it is not rated for 1.8V operation. Operating below 2.5V may result in undefined behavior, failed writes, or I²C communication errors. Always verify VCC stability under load using the 24LC32AXT-I/ST's 1 μA standby current and 3 mA max active current specs.

Does the 24LC32AXT-I/ST support 100 kHz I²C communication?

Yes, the 24LC32AXT-I/ST supports 100 kHz I²C communication, though its maximum rated frequency is 400 kHz at VCC ≥ 2.5V. The device fully complies with standard-mode I²C timing (Table 1-2), including THD:STA ≥ 600 ns and TSU:DAT ≥ 100 ns. No configuration is needed - it automatically adapts to master clock rate, making it compatible with legacy microcontrollers and mixed-speed I²C buses.

How does the WP pin function on the 24LC32AXT-I/ST, and what happens if it toggles during a write?

The WP pin on the 24LC32AXT-I/ST is sampled only at the Stop bit of each write command. When tied to VCC, it disables all write operations (byte/page) while permitting reads; when tied to VSS, full read/write access is enabled. Toggling WP after the Stop bit has no effect - the write cycle proceeds or aborts based on the sampled state. This ensures deterministic protection even in electrically noisy environments.

Can multiple 24LC32AXT-I/ST devices share the same I²C bus, and how are they addressed?

Yes, up to eight 24LC32AXT-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 0x52). All devices respond only to commands matching their unique A2–A0 combination, enabling scalable memory expansion without address conflicts.

What is the page write limit and boundary behavior for the 24LC32AXT-I/ST?

The 24LC32AXT-I/ST supports 32-byte page writes, but physical page boundaries align to 32-byte offsets (e.g., 0x000–0x01F, 0x020–0x03F). If a page write crosses a boundary, data wraps to the start of the current page instead of advancing - overwriting prior bytes. Applications must split writes at 32-byte intervals; the 24LC32AXT-I/ST does not auto-segment across pages.