Microchip Technology 24AA52-I/MS

Overview

24AA52-I/MS 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 (100 kHz below 2.2V), 1 mA typical active current, and 1 µA typical standby current. It provides dual write protection-software-based for lower 128 bytes (00h–7Fh) and hardware-based via the WP pin for full-array protection-and supports page writes of up to 16 bytes.

For engineers reviewing the 24AA52-I/MS datasheet, 24AA52-I/MS pinout, 24AA52-I/MS application, or 24AA52-I/MS equivalent, key selection considerations include its industrial-grade temperature range (−40°C to +85°C), MSOP-8 package footprint, Schmitt-trigger noise immunity on SDA/SCL, and compatibility with standard I²C bus timing requirements at both 100 kHz and 400 kHz.

Technical Context

The 24AA52-I/MS functions as an I²C slave device with a fixed 7-bit address prefix (1010b) and three programmable chip-select bits (A2–A0), enabling up to eight devices on a single bus. Its internal architecture includes a 16-byte page buffer, address pointer auto-increment logic, and a VCC threshold detector that disables write operations below 1.5V.

Write protection is implemented through two independent mechanisms: a one-time-programmable software register locking addresses 00h–7Fh, and a hardware WP pin that overrides all software settings when pulled high. Acknowledge polling is supported to detect write-cycle completion without fixed delay timing.

Key Specifications

Pinout & Package

24AA52-I/MS is housed in an 8-pin MSOP (Micro Small Outline Package) with 0.65 mm lead pitch, 3.0 mm × 3.0 mm body, and exposed pad option (connected to VSS or left floating per design).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24LC52-I/MS and AT24C02C-MAHM-T, the 24AA52-I/MS uniquely supports true 1.8V operation with full 400 kHz performance and offers irreversible software write-protection - making it optimal for ultra-low-power, safety-critical, or field-programmable applications requiring guaranteed data integrity.

Availability

24AA52-I/MS is available at Aetrix Electronics and suitable for industrial sensor calibration, medical device configuration, automotive body control modules, and smart energy meter firmware patch storage requiring stable component supply across extended product lifecycles.

Supply support for 24AA52-I/MS 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 manufacturer specializing in microcontrollers, analog devices, and nonvolatile memory solutions for embedded control applications.

The 24AAxx family was designed specifically for reliable, low-power, I²C-based configuration and parameter storage in industrial, automotive, and medical systems requiring long-term data integrity and robust noise immunity.

FAQ

What is the maximum I²C clock frequency supported by the 24AA52-I/MS?

The 24AA52-I/MS supports up to 400 kHz when VCC is 2.2V or higher. At supply voltages between 1.8V and 2.2V, the maximum clock frequency is reduced to 100 kHz to ensure timing compliance. This dual-speed capability allows designers to maintain full functionality across wide input voltage ranges without sacrificing bus throughput in higher-voltage domains. The 24AA52-I/MS datasheet specifies exact setup/hold times for both conditions.

Does the 24AA52-I/MS require external pull-up resistors on SDA and SCL lines?

Yes, the 24AA52-I/MS requires external pull-up resistors on both SDA and SCL lines because its I/O pins are open-drain. Recommended values are 2 kΩ for 400 kHz operation and 10 kΩ for 100 kHz. These values balance rise time, power consumption, and noise immunity. The 24AA52-I/MS internal Schmitt triggers and slope control work in conjunction with these resistors to meet I²C bus specification timing margins.

How does hardware write protection work on the 24AA52-I/MS?

Hardware write protection on the 24AA52-I/MS is controlled by the WP pin: when tied to VCC, it disables all write operations to the entire memory array regardless of software write-protect status. When tied to VSS, hardware protection is disabled and software protection (for lower 128 bytes) governs access. The WP pin takes precedence - even if software protection is unprogrammed, pulling WP high locks the full 256-byte block. This behavior is explicitly defined in the 24AA52-I/MS functional description.

Can the software write-protect feature of the 24AA52-I/MS be reversed after programming?

No - once the software write-protect register is set on the 24AA52-I/MS, it cannot be reversed through normal I²C commands. However, Microchip documents a dedicated reset procedure (RWPF command) requiring VCC + 5.5V applied to the WP pin for 1 µs prior to issuing a specific 1001b control sequence. This high-voltage reset is not part of standard operation and must be implemented with caution. The 24AA52-I/MS datasheet confirms the fuse is one-time programmable under normal conditions.

What package type does the 24AA52-I/MS use, and what are its key mechanical dimensions?

The 24AA52-I/MS uses an 8-pin MSOP (Micro Small Outline Package) with 0.65 mm lead pitch, 3.0 mm × 3.0 mm body size, and 1.1 mm maximum height. The package includes an exposed thermal pad (pin 9) that may be connected to VSS or left floating per layout requirements. Lead finish is Pb-free matte tin, and the marking "A52" appears on the top surface per Microchip's standard 24AA52-I/MS packaging specification.