Microchip Technology 24AA1025-I/SN

Overview

24AA1025-I/SN from Microchip Technology Inc. is a 128K × 8 (1024 kbit) I²C-compatible serial EEPROM with 1.7–5.5 V supply range, 400 kHz max clock (100 kHz below 2.5 V), and industrial temperature rating (–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-used in embedded system configuration storage, sensor calibration data retention, and firmware parameter backup.

For engineers reviewing the 24AA1025-I/SN datasheet, 24AA1025-I/SN pinout, 24AA1025-I/SN application, or 24AA1025-I/SN equivalent, key selection criteria include voltage compatibility (1.7–5.5 V), I²C timing compliance at target VCC, page boundary handling in firmware, and hardware write-protect implementation using the dedicated WP terminal.

Technical Context

The 24AA1025-I/SN operates as an I²C slave device with fixed 4-bit control code '1010', block-select bit (B0) enabling access to two 512 kbit memory segments (00000h–0FFFFh and 10000h–1FFFFh), and user-configurable chip address bits A0/A1 supporting up to four devices on one bus. Its internal address pointer auto-increments during sequential reads and wraps within each 512 kbit segment.

Write operations are self-timed: byte writes complete in ≤5 ms, page writes (up to 128 bytes) also require ≤5 ms. During active write cycles, the device inhibits ACK responses-enabling reliable acknowledge polling without timeout assumptions. The WP pin is sampled only at the STOP condition of each write command.

Key Specifications

Pinout & Package

24AA1025-I/SN is housed in an 8-lead SOIC (Small Outline Integrated Circuit) package with 3.90 mm body width, RoHS-compliant matte tin (Sn) lead finish, and standard 1.27 mm pitch. Pin 1 is marked with a beveled corner or dot.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24LC1025-I/SN, the 24AA1025-I/SN offers lower-voltage operation (down to 1.7 V) at the cost of reduced temperature range; versus AT24C1024, it trades higher speed and smaller page size for broader voltage compatibility and simpler firmware page-alignment logic.

Availability

24AA1025-I/SN 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 multi-year production cycles.

Supply support for 24AA1025-I/SN 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 nonvolatile memory solutions for embedded control applications.

The 24AA1025-I/SN belongs to Microchip's 24XX series of I²C EEPROMs, designed specifically for low-power, wide-voltage-range data retention in space-constrained and battery-operated systems.

FAQ

What is the minimum V_CC required for reliable operation of the 24AA1025-I/SN?

The 24AA1025-I/SN operates reliably down to 1.7 V, with guaranteed I²C timing compliance at 100 kHz below this threshold. At 1.7–2.49 V, clock frequency must be limited to 100 kHz; operation above 2.5 V permits 400 kHz. This makes the 24AA1025-I/SN suitable for single-cell Li-ion or alkaline-powered systems where supply voltage drops during discharge.

How does the WP pin function on the 24AA1025-I/SN, and when is it sampled?

The WP pin on the 24AA1025-I/SN is sampled only at the STOP condition of each write command. When tied to VCC, all write operations (byte and page) are inhibited while read operations remain fully functional. Toggling WP during an ongoing write has no effect - the decision is latched once per command, ensuring deterministic behavior in safety-critical firmware.

Can the 24AA1025-I/SN perform sequential reads across its full 1024 kbit address space?

No. Sequential reads on the 24AA1025-I/SN are limited to 512 kbit segments: addresses 00000h–0FFFFh and 10000h–1FFFFh. The block-select bit (B0) must be toggled between segments. Attempting to read past 0FFFFh will wrap to 00000h; reading past 1FFFFh wraps to 10000h. Firmware must issue separate read commands for cross-segment access.

What is the actual page size of the 24AA1025-I/SN, and why does page write alignment matter?

The 24AA1025-I/SN has a 128-byte physical page size, with boundaries at integer multiples of 128 (e.g., 0x0000–0x007F, 0x0080–0x00FF). Page writes crossing these boundaries wrap within the current page instead of advancing to the next - causing unintended overwrites. Firmware must validate starting address modulo 128 before initiating multi-byte writes.

Does the 24AA1025-I/SN support cascading with other I²C EEPROMs, and how many devices can share one bus?

Yes. The 24AA1025-I/SN supports cascading via A0 and A1 pins, allowing up to four devices on a single I²C bus. Each device uses a unique 2-bit chip address (00, 01, 10, or 11), enabling a total system capacity of 4 Mbit (4 × 1024 kbit). A2 is fixed to VCC and does not contribute to addressing.