Microchip Technology 24LC32A-I/SM

Overview

24LC32A-I/SM from Microchip Technology is a 32-Kbit I²C serial EEPROM organized as 4K × 8-bit, operating from 2.5V to 5.5V with industrial temperature range (–40°C to +85°C) and housed in an 8-lead MSOP package. It supports 400 kHz clock frequency, features hardware write-protection via WP pin, and delivers 1 µA standby current and 3 mA active write current. It is used for nonvolatile parameter storage in embedded controllers, sensor calibration data retention, and configuration memory in industrial control modules.

For engineers reviewing the 24LC32A-I/SM datasheet, 24LC32A-I/SM pinout, 24LC32A-I/SM application, or 24LC32A-I/SM equivalent, key selection considerations include VCC min/max compatibility (2.5V–5.5V), I²C timing compliance at 400 kHz, page write buffer size (32 bytes), endurance (1 million cycles), and hardware write-protect implementation using the WP pin.

Technical Context

The 24LC32A-I/SM implements a two-wire I²C-compatible interface with Schmitt-trigger inputs on SDA/SCL for noise immunity and slope-controlled outputs to suppress ground bounce. Its internal architecture includes a 32-byte page write buffer, address pointer logic for sequential access, and a self-timed erase/write cycle with automatic completion detection via ACK polling.

It uses three chip-address inputs (A0–A2) to support up to eight devices on a shared bus, with device addressing based on the 4-bit control code '1010' followed by A2:A0 bits and R/W bit. The WP pin samples at the Stop bit to enable/disable writes, and all I/O pins meet ±1 µA leakage and >4 kV ESD specifications.

Key Specifications

Pinout & Package

24LC32A-I/SM is packaged in an 8-lead MSOP (3×3 mm body, 0.65 mm pitch) with exposed pad optional for thermal relief or grounding. Pin 1 is marked by a beveled corner or dot; pin numbering follows standard MSOP convention (counterclockwise from top-left when marking side faces up).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT24C32D-SSHM-T and BR24G32FJ-3GE2, the 24LC32A-I/SM uniquely combines AEC-Q100 qualification, industrial temperature rating, hardware write protection, and full 3-pin addressability in an MSOP package-making it optimal for automotive and high-reliability industrial I²C memory nodes.

Availability

24LC32A-I/SM 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 24LC32A-I/SM 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 devices, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing infrastructure.

The 24LC32A belongs to Microchip's serial EEPROM product line, designed specifically for reliable, low-power nonvolatile data storage in resource-constrained embedded systems with I²C interfaces.

FAQ

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

The 24LC32A-I/SM requires a minimum supply voltage of 2.5V for guaranteed operation across its full industrial temperature range (–40°C to +85°C). Unlike the 24AA32A variant, it is not rated for 1.7V operation. Operating below 2.5V may result in undefined behavior, failed writes, or incomplete ACK polling responses. Always verify VCC stability during brown-out conditions in the target application.

How does the WP pin function on the 24LC32A-I/SM, and when is it sampled?

The WP (Write-Protect) pin on the 24LC32A-I/SM is sampled at the Stop bit of each I²C write command. When tied to VCC, all write operations-including byte and page writes-are inhibited, while read operations remain fully functional. Toggling WP after the Stop bit has no effect on an ongoing write cycle. This hardware-level protection prevents accidental overwrites during firmware updates or power transitions.

Can multiple 24LC32A-I/SM devices share the same I²C bus, and how is addressing managed?

Yes, up to eight 24LC32A-I/SM devices can share one I²C bus using the A0, A1, and A2 address pins. Each pin must be hardwired to VSS or VCC to set a unique 3-bit chip address. The full 7-bit client address is formed as '1010' + A2A1A0, allowing distinct addressing without software arbitration. All devices respond only to their configured address, enabling scalable memory expansion up to 256 Kbits.

What is the maximum page write size supported by the 24LC32A-I/SM, and what happens if more than 32 bytes are sent?

The 24LC32A-I/SM supports a maximum page write size of 32 bytes. If more than 32 bytes are transmitted before the Stop condition, the internal address pointer rolls over within the same physical page (addresses aligned to 32-byte boundaries), overwriting previously loaded data in FIFO order. To avoid unintended data loss, host firmware must enforce page boundary alignment and limit transmissions to ≤32 bytes per write transaction.

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

Yes, the 24LC32A-I/SM is AEC-Q100 qualified for automotive applications. It meets stress test requirements for temperature cycling, humidity bias, and ESD robustness per Grade 3 (–40°C to +85°C ambient). This qualification confirms suitability for use in body electronics, infotainment, and other non-safety-critical automotive subsystems where reliability under harsh environmental conditions is mandatory.