Microchip Technology 24LC32AXT-E/ST

Overview

24LC32AXT-E/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 page writes up to 32 bytes and is qualified for industrial and automotive applications including infotainment control storage and sensor calibration data retention.

For engineers reviewing the 24LC32AXT-E/ST datasheet, 24LC32AXT-E/ST pinout, 24LC32AXT-E/ST application, or 24LC32AXT-E/ST equivalent, key selection criteria include VCC range compatibility (2.5–5.5V), automotive temperature rating (−40°C to +125°C), TSSOP-8 package footprint, and I²C bus timing compliance at 400 kHz.

Technical Context

The 24LC32AXT-E/ST implements a slave-only I²C interface with fixed 7-bit address prefix '1010' and three programmable chip-select bits (A2/A1/A0), enabling up to eight devices on one bus. Its internal architecture includes a 32-byte page latch, Schmitt-triggered SDA/SCL inputs for noise immunity, and slope-controlled outputs to suppress ground bounce.

Write operations are self-timed with 5 ms typical cycle time; endurance is rated at 1 million erase/write cycles and data retention exceeds 200 years. The device uses on-chip charge pump for EEPROM programming and supports acknowledge polling to detect write completion without fixed delay timing.

Key Specifications

Pinout & Package

24LC32AXT-E/ST is housed in an 8-lead TSSOP package (4.4 mm body width, JEDEC MO-153), optimized for space-constrained automotive PCBs and surface-mount assembly. Pin 1 is marked by a dot or notch; orientation follows standard TSSOP pin 1 indicator (top-left corner 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-E/ST, the 24LC32AT-I/ST offers identical performance at lower cost but lacks automotive qualification, while the AT24C32D-SSHM-T omits hardware write protection and uses a non-interchangeable address scheme - making 24LC32AXT-E/ST the sole choice for AEC-Q100-compliant designs requiring robust, pin-level write security.

Availability

24LC32AXT-E/ST is available at Aetrix Electronics and suitable for automotive infotainment systems, industrial PLCs, and medical diagnostic devices requiring stable component supply across extended product lifecycles.

Supply support for 24LC32AXT-E/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, FPGA, and memory solutions, with core expertise in embedded control and nonvolatile data storage.

The 24LC32A family was designed specifically for automotive and industrial applications demanding high reliability, extended temperature operation, and robust I²C interface performance in harsh electromagnetic environments.

FAQ

What is the maximum I²C clock frequency supported by the 24LC32AXT-E/ST?

The 24LC32AXT-E/ST supports up to 400 kHz clock frequency when VCC is 2.5V or higher. At voltages below 2.5V, the device is not rated for operation - this limit is specific to the 24LC32A variant and distinguishes it from the 24AA32A, which supports 100 kHz down to 1.8V. Always verify VCC stability before enabling 400 kHz mode in 24LC32AXT-E/ST designs.

Does the 24LC32AXT-E/ST require external pull-up resistors on SDA and SCL lines?

Yes, the 24LC32AXT-E/ST requires external pull-up resistors on both SDA and SCL lines because these pins are open-drain. For 400 kHz operation, a 2 kΩ pull-up to VCC is recommended; for 100 kHz (if used with compatible master), 10 kΩ is typical. Incorrect pull-up values may cause timing violations or bus lockup - always validate with oscilloscope measurements on actual 24LC32AXT-E/ST hardware.

How does the WP pin function on the 24LC32AXT-E/ST?

The WP (Write-Protect) pin on the 24LC32AXT-E/ST is an active-high input that disables all write operations when pulled to VCC. When tied to VSS, full read/write access is enabled. The pin is sampled at the Stop bit of each write command - toggling WP mid-cycle has no effect. This hardware-level protection prevents accidental overwrites during power transitions, making it essential for safeguarding calibration data in 24LC32AXT-E/ST deployments.

Can multiple 24LC32AXT-E/ST devices share the same I²C bus?

Yes, up to eight 24LC32AXT-E/ST devices can operate on a single I²C bus using the A2, A1, and A0 address pins to configure unique 7-bit slave addresses. Each device must have a distinct combination of logic levels on these pins; floating address pins are not allowed. This cascading capability enables scalable memory expansion - for example, eight 24LC32AXT-E/ST units provide 256 Kbit of contiguous address space.

What is the write endurance and data retention specification for the 24LC32AXT-E/ST?

The 24LC32AXT-E/ST is rated for 1,000,000 erase/write cycles and guarantees data retention exceeding 200 years at +25°C ambient. These specifications are validated per Microchip's characterization methodology and apply across the full automotive temperature range (−40°C to +125°C). Field reliability models confirm that actual retention remains >100 years even at +125°C - critical for mission-critical 24LC32AXT-E/ST applications in automotive ECUs.