Microchip Technology 24AA52T-I/ST

Overview

24AA52T-I/ST from Microchip Technology Inc. is a 2 Kbit I²C-compatible serial EEPROM organized as one 256 × 8-bit block, operating from 1.8V to 5.5V with 400 kHz max clock frequency (100 kHz below 2.2V), 1 mA typical active current, and 1 µA typical standby current for industrial-temperature (-40°C to +85°C) embedded systems requiring nonvolatile parameter storage.

For engineers reviewing the 24AA52T-I/ST datasheet, 24AA52T-I/ST pinout, 24AA52T-I/ST application, or 24AA52T-I/ST equivalent, key selection considerations include software/hardware write-protection flexibility, page-write buffer (up to 16 bytes), Schmitt-trigger noise immunity, and TSSOP-8 packaging compatibility with space-constrained PCB layouts.

Technical Context

The 24AA52T-I/ST implements a standard two-wire I²C interface with master-controlled SCL/SDA timing, supporting byte and page write operations with self-timed internal erase/write cycles up to 5 ms. Its address decoding uses three hardware address pins (A0–A2) enabling up to eight devices on a single bus.

Write protection operates at two levels: hardware-level array-wide lock via the WP pin tied to VCC, and software-level permanent lock of the lower 128-byte block (00h–7Fh) via dedicated control code (0110) - both enforce data integrity without external logic.

Key Specifications

Pinout & Package

24AA52T-I/ST is supplied in an 8-lead TSSOP package (3.0 mm × 4.4 mm, 0.65 mm pitch), optimized for automated surface-mount assembly and thermal performance in dense layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24AA52T-I/ST, the 24LC52-I/ST offers identical functionality above 2.2V but excludes 1.8V operation, while the AT24C02C-SSHM-T provides faster I²C timing yet omits the hardware-enforced software write-protect fuse - making 24AA52T-I/ST uniquely suited for ultra-low-voltage, safety-critical, or tamper-resistant use cases.

Availability

24AA52T-I/ST is available at Aetrix Electronics and suitable for smart sensor calibration, industrial PLC configuration, and medical device settings requiring stable component supply across extended production lifecycles.

Supply support for 24AA52T-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 for embedded control applications.

The 24AA52T-I/ST belongs to Microchip's legacy 24XX serial EEPROM product line, designed specifically for reliable, low-power, I²C-based nonvolatile storage in cost-sensitive industrial, automotive, and consumer systems.

FAQ

What is the maximum I²C clock frequency supported by the 24AA52T-I/ST?

The 24AA52T-I/ST supports up to 400 kHz when VCC is ≥2.2V; below 2.2V (down to 1.8V), the maximum clock frequency is reduced to 100 kHz to ensure timing margin and signal integrity. This dual-speed capability allows seamless integration across diverse supply rail architectures without redesigning the I²C bus interface. The 24AA52T-I/ST datasheet specifies these limits under AC Characteristics (Table 1-2, Param No. 1).

How does hardware write-protection work on the 24AA52T-I/ST?

Hardware write-protection on the 24AA52T-I/ST is controlled by the WP pin: tying WP to VCC disables all write operations to the entire memory array, regardless of software write-protect status. If WP is tied to VSS, write access is governed solely by the software write-protect register. This dual-layer scheme ensures fail-safe data integrity - for example, in medical devices where critical calibration data must survive firmware errors. The 24AA52T-I/ST Pin Description section (DS21166K-page 5) confirms this behavior.

Can the 24AA52T-I/ST be used with a 1.8V microcontroller I²C interface?

Yes, the 24AA52T-I/ST is fully compatible with 1.8V microcontrollers: its VCC range is 1.8V to 5.5V, and its I²C inputs (SCL, SDA, WP, A0–A2) meet VIH ≥0.7×VCC and VIL ≤0.3×VCC thresholds at 1.8V. Pull-up resistors should be sized for 1.8V operation (e.g., ~10 kΩ for 100 kHz). This makes the 24AA52T-I/ST ideal for battery-powered or energy-harvesting systems where low-voltage operation is mandatory. Electrical Characteristics (Table 1-1, D2/D3) validate this compatibility.

What is the purpose of the software write-protect register in the 24AA52T-I/ST?

The software write-protect register in the 24AA52T-I/ST permanently locks the lower 128 bytes (addresses 00h–7Fh) against writes once programmed using the dedicated 0110 control code. Unlike hardware WP, this protection persists even if WP is later grounded, providing immutable storage for factory-set parameters like calibration constants or security keys. The 24AA52T-I/ST Functional Description (Section 7.1) details this irreversible fuse-like behavior.

Does the 24AA52T-I/ST support page write operations, and what is the buffer size?

Yes, the 24AA52T-I/ST supports page write operations with a 16-byte internal buffer, allowing up to 16 sequential bytes to be loaded before initiating the internal write cycle. This reduces I²C transaction count and improves throughput versus byte-by-byte writes. Page boundaries align to 16-byte increments (00h–0Fh, 10h–1Fh, etc.), and crossing boundaries causes wraparound - so host firmware must manage alignment. The 24AA52T-I/ST Write Operations section (DS21166K-page 7) defines this constraint explicitly.