Microchip Technology 24AA1025T-I/SM

Overview

24AA1025T-I/SM from Microchip Technology Inc. is a 128K × 8 (1024 kbit) I²C-compatible serial EEPROM with 1.7–5.5 V operation, 400 kHz max clock (100 kHz below 2.5 V), and industrial temperature range (–40°C to +85°C). It features 128-byte page write buffer, hardware write-protection via WP pin, and Schmitt-trigger inputs for noise immunity - deployed in embedded system configuration storage, sensor calibration data retention, and power-fail-safe parameter logging.

For engineers reviewing the 24AA1025T-I/SM datasheet, 24AA1025T-I/SM pinout, 24AA1025T-I/SM application, or 24AA1025T-I/SM equivalent, key selection criteria include voltage compatibility (1.7–5.5 V), I²C timing compliance at target VCC, page boundary-aware write sequencing, and WP pin logic-level dependency for write-enable control.

Technical Context

The 24AA1025T-I/SM implements a two-wire I²C slave interface with fixed 4-bit device identifier '1010', configurable A0/A1 address bits enabling up to four devices on one bus, and mandatory A2 tied to VCC. It supports byte and page write modes, with internal address pointer auto-increment and dual 512 kbit memory segments selected by block bit B0.

Read operations include current-address, random, and sequential modes - the latter limited to 512 kbit boundaries (00000h–0FFFFh and 10000h–1FFFFh). Acknowledge polling is required to detect write completion, as the device halts ACK generation during self-timed erase/write cycles lasting up to 5 ms.

Key Specifications

Pinout & Package

24AA1025T-I/SM is housed in an 8-lead SOIC package (3.90 mm wide), RoHS-compliant and Pb-free, with standard 1.27 mm pitch and JEDEC MS-012AC outline.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24AA1025T-I/SM, the 24LC1025-I/SM trades voltage flexibility for extended temperature capability, while the AT24C1024-MAHM-T simplifies address wiring at the cost of multi-device scalability - both require validation of WP pin behavior and page write boundary handling in firmware.

Availability

24AA1025T-I/SM is available at Aetrix Electronics and suitable for industrial sensor nodes, medical device calibration storage, and smart energy metering requiring stable component supply across long product lifecycles.

Supply support for 24AA1025T-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 microcontroller, analog, FPGA, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 24AA1025T-I/SM belongs to Microchip's 24XX serial EEPROM family, engineered for ultra-low-power, high-reliability nonvolatile storage in space-constrained embedded systems where voltage flexibility and I²C simplicity are critical.

FAQ

What is the minimum VCC required for reliable operation of the 24AA1025T-I/SM?

The 24AA1025T-I/SM operates reliably from 1.7 V to 5.5 V. At VCC < 2.5 V, maximum I²C clock frequency is limited to 100 kHz per datasheet DS20001941L, and DC characteristics such as VOL and VIH scale proportionally. Below 1.7 V, functionality is not guaranteed and may result in incomplete writes or read errors.

How does the A2 pin function on the 24AA1025T-I/SM, and what happens if it is left unconnected?

The A2 pin on the 24AA1025T-I/SM is a non-configurable chip select input that must be hard-wired to VCC for normal operation. If left floating or tied to VSS, device operation becomes undefined - the part will not respond to I²C commands or generate acknowledgments, rendering it nonfunctional on the bus.

Can the 24AA1025T-I/SM perform sequential reads across its full 1024 kbit address space?

No. Sequential reads on the 24AA1025T-I/SM are limited to 512 kbit boundaries: 00000h–0FFFFh and 10000h–1FFFFh. Attempting to read past 0FFFFh rolls the internal address pointer back to 00000h; crossing from 1FFFFh returns to 10000h. To access the full array sequentially, software must issue separate read commands for each segment.

What is the purpose of acknowledge polling with the 24AA1025T-I/SM, and how is it implemented?

Acknowledge polling detects write completion on the 24AA1025T-I/SM by repeatedly sending a Start condition followed by the same write control byte (R/W = 0) used to initiate the write. The device withholds ACK until the internal 5 ms write cycle finishes. This avoids fixed delays and maximizes I²C bus utilization in time-sensitive applications.

Does the 24AA1025T-I/SM support 1 MHz I²C operation like the 24FC1025 variant?

No. The 24AA1025T-I/SM supports up to 400 kHz I²C clock frequency at VCC ≥ 2.5 V, and 100 kHz below 2.5 V. The 1 MHz capability is exclusive to the 24FC1025 variant; using 24AA1025T-I/SM at 1 MHz violates AC timing specifications and will result in communication failures or corrupted writes.