Microchip Technology 24LC32AT/SM

Overview

24LC32AT/SM from Microchip Technology Inc. is a 32-Kbit I²C-compatible serial EEPROM organized as 4K × 8-bit memory with hardware write-protection, 32-byte page buffer, and operation from 2.5V to 5.5V. It supports 400 kHz clock frequency at V_CC ≥ 2.5V, delivers ≤1 µA standby current, and guarantees >1 million erase/write cycles with >200 years data retention. It is used in industrial sensor calibration storage and embedded system configuration backup.

For engineers reviewing the 24LC32AT/SM datasheet, 24LC32AT/SM pinout, 24LC32AT/SM application, or 24LC32AT/SM equivalent, this page provides verified electrical parameters, package-specific terminal mapping for the 8-lead SOIJ (SM) variant, real-world use cases, and two confirmed alternative parts with documented functional and application-level differences.

Technical Context

The 24LC32AT/SM implements a two-wire I²C interface with Schmitt-trigger inputs on SDA and SCL for noise immunity, slope-controlled outputs to suppress ground bounce, and internal address pointer logic enabling current-address, random, and sequential read modes. Its 32-byte page write buffer allows burst writes within a single physical page boundary (0–31, 32–63, etc.), with automatic wraparound if crossed.

Write protection is enforced via the WP pin: tied to V_CC, it inhibits all array writes while permitting reads; tied to V_SS, full read/write access is enabled. Acknowledge polling is supported to detect write-cycle completion without fixed delay timing, improving bus efficiency in multi-device systems.

Key Specifications

Pinout & Package

24LC32AT/SM is supplied in an 8-lead SOIJ (Small Outline J-Bend) package, 5.28 mm body width, with gull-wing leads and JEDEC MS-012AC compliant footprint. Pin 1 is marked by a notch or beveled corner on the package top edge.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24LC32AT/SM, the 24LC32A-I/P offers identical functionality in through-hole form for legacy integration, while the AT24C32D-SSHM-T extends voltage range and speed but requires validation of 1.8V logic compatibility and WP timing alignment in existing firmware.

Availability

24LC32AT/SM is available at Aetrix Electronics and suitable for industrial sensor calibration storage, embedded system configuration backup, and medical device parameter archiving requiring stable component supply across extended product lifecycles.

Supply support for 24LC32AT/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 global semiconductor company specializing in microcontrollers, analog devices, and nonvolatile memory solutions, with ISO 9001-certified manufacturing and AEC-Q100-qualified automotive products.

The 24LC32A family delivers cost-optimized, low-power serial EEPROMs targeting industrial, medical, and automotive applications where robustness, long-term data integrity, and I²C simplicity are essential.

FAQ

What is the maximum clock frequency supported by the 24LC32AT/SM?

The 24LC32AT/SM supports a maximum clock frequency of 400 kHz when V_CC is 2.5V or higher. At voltages below 2.5V, the maximum clock rate drops to 100 kHz. This dual-speed capability ensures compatibility with both legacy 100 kHz I²C systems and modern fast-mode buses, and is explicitly defined in Table 1-2 of the DS20001713P datasheet for the 24LC32A series.

Does the 24LC32AT/SM support hardware write protection, and how is it implemented?

Yes, the 24LC32AT/SM implements hardware write protection via the WP (Write-Protect) pin. When WP is tied to V_CC, all write operations-including byte and page writes-are inhibited, while read operations remain fully functional. The pin is sampled at the Stop bit of each write command, making protection effective immediately without software intervention. This feature is documented in Section 2.4 and Figure 6-1 of DS20001713P.

What package type does the 24LC32AT/SM use, and what are its key mechanical features?

The 24LC32AT/SM uses an 8-lead SOIJ (Small Outline J-Bend) package, 5.28 mm body width, with gull-wing leads conforming to JEDEC MS-012AC. Key features include a notch or beveled corner for pin 1 identification, 0.65 mm pitch, and compatibility with standard reflow soldering profiles. Package dimensions and land pattern recommendations are provided in DS20001713P pages 18–20.

How many devices can share the same I²C bus using the 24LC32AT/SM?

Up to eight 24LC32AT/SM devices can operate on the same I²C bus using the three hardware address pins A0, A1, and A2. Each combination of logic levels on these pins sets a unique 3-bit chip address (000–111), allowing individual selection within a total address space of 256 Kbits. This multi-device addressing is detailed in Section 5.0 and Figure 5-1 of DS20001713P.

What is the page write buffer size of the 24LC32AT/SM, and why does it matter for system design?

The 24LC32AT/SM has a 32-byte page write buffer, meaning up to 32 bytes can be written in a single I²C transaction before the internal self-timed write cycle begins. This reduces bus overhead and improves efficiency when updating configuration blocks or calibration tables. However, writes crossing physical page boundaries (every 32 bytes) wrap around instead of advancing - a constraint requiring firmware to align writes, as specified in Section 6.2 of DS20001713P.