Microchip Technology 24LC32A-I/ST

Overview

24LC32A-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) in an 8-lead SOIC package. It delivers low-power operation (1 µA standby, 1 mA active), hardware write-protection via WP pin, and Schmitt-trigger inputs for noise immunity - deployed in embedded system configuration storage, sensor calibration data retention, and firmware parameter backup.

For engineers reviewing the 24LC32A-I/ST datasheet, 24LC32A-I/ST pinout, 24LC32A-I/ST application, or 24LC32A-I/ST equivalent, key selection considerations include VCC min/max compatibility (2.5V–5.5V), I²C bus timing at 400 kHz, 32-byte page buffer constraints, WP pin logic behavior, and SOIC-8 package footprint requirements.

Technical Context

The 24LC32A-I/ST implements a two-wire I²C-compatible interface with open-drain SDA/SCL pins requiring external pull-ups, supports up to eight devices on one bus via A0–A2 address inputs, and uses internal address pointer auto-increment for sequential reads. Its EEPROM array features self-timed erase/write cycles and hardware write-protection activated when WP = VCC.

It employs Schmitt-trigger inputs on SDA and SCL for robust noise suppression, slope-controlled outputs to minimize ground bounce, and supports both byte and page write modes - with page writes limited to 32-byte boundaries aligned to physical page starts (e.g., addresses 0x000–0x01F).

Key Specifications

Pinout & Package

24LC32A-I/ST is supplied in an 8-lead SOIC (Small Outline Integrated Circuit) package with 1.27 mm pitch, 3.90 mm body width, and standard JEDEC MS-012AC footprint. Pin 1 is marked by a beveled corner or notch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24AA32A-I/ST and AT24C32D-SSHM-T, the 24LC32A-I/ST provides guaranteed 2.5V–5.5V operation, AEC-Q100 qualification, and faster 5 ms write cycles - making it optimal for automotive and industrial systems requiring deterministic timing and extended temperature compliance.

Availability

24LC32A-I/ST is available at Aetrix Electronics and suitable for industrial sensor nodes, medical device calibration storage, and smart energy metering requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for 24LC32A-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 U.S.-based semiconductor company specializing in microcontrollers, analog devices, and memory solutions, with global manufacturing and quality certifications including ISO 9001 and IATF 16949.

The 24LC32A belongs to Microchip's serial EEPROM product line, designed specifically for reliable, low-power nonvolatile data storage in space-constrained embedded systems across industrial, automotive, and medical applications.

FAQ

What is the minimum supply voltage required for reliable operation of the 24LC32A-I/ST?

The 24LC32A-I/ST requires a minimum VCC of 2.5V for guaranteed operation across its full industrial temperature range (–40°C to +85°C). Operation below 2.5V is not specified and may result in undefined behavior or failure to complete write cycles. This distinguishes it from the 24AA32A variant, which supports down to 1.7V.

How does the WP pin function on the 24LC32A-I/ST, and what happens if it floats?

On the 24LC32A-I/ST, the WP (Write-Protect) pin must be actively driven to either VCC (to disable writes) or VSS (to enable writes). If left floating, the pin state is indeterminate and may cause intermittent write failures or unintended protection - Microchip specifies that WP must be hardwired, not left unconnected.

Can the 24LC32A-I/ST perform page writes across address boundaries, and what occurs if it does?

No - the 24LC32A-I/ST restricts page writes to within a single 32-byte physical page (e.g., 0x000–0x01F). Attempting a page write that crosses a boundary causes address wraparound: data intended for the next page overwrites earlier bytes in the current page. Application firmware must enforce page-aligned write addressing.

What is the maximum I²C clock frequency supported by the 24LC32A-I/ST, and under what conditions?

The 24LC32A-I/ST supports up to 400 kHz I²C clock frequency when VCC is between 2.5V and 5.5V. This is its rated Fast-Mode capability. At VCC < 2.5V - which falls outside its specified operating range - the device would default to 100 kHz, but such operation is not guaranteed or recommended.

Is the 24LC32A-I/ST qualified for automotive applications, and what certification does it hold?

Yes, the 24LC32A-I/ST is AEC-Q100 qualified for automotive applications. This qualification covers stress testing for temperature cycling, humidity, mechanical shock, and electrical reliability - confirming suitability for use in body control modules, infotainment systems, and other vehicle subsystems requiring high-reliability nonvolatile memory.