Microchip Technology AT24C1024BW-SH25-B

Overview

AT24C1024BW-SH25-B from Microchip Technology (formerly Atmel) is a 1 Mbit (131,072 × 8) two-wire serial EEPROM with 2.5V operation (2.5V to 5.5V), 8-lead EIAJ SOIC package, hardware write protection via WP pin, and 400 kHz/1 MHz clock support. It enables nonvolatile data storage in space-constrained industrial control modules requiring low-voltage compatibility and cascaded bus topology.

For engineers reviewing the AT24C1024BW-SH25-B datasheet, AT24C1024BW-SH25-B pinout, AT24C1024BW-SH25-B application, or AT24C1024BW-SH25-B equivalent, key selection considerations include its 2.5V supply range, 256-byte page write capability, Schmitt-triggered inputs for noise immunity, 1,000,000 write endurance per page, and cascading support for up to four devices on a shared I²C bus.

Technical Context

The AT24C1024BW-SH25-B implements a standard two-wire (I²C-compatible) interface with bidirectional SDA and unidirectional SCL, supporting both byte and 256-byte page writes. Its internal 17-bit address counter enables random and sequential read modes, while device addressing uses A1/A2 pins to select among up to four devices on the same bus.

It features hardware write protection via the WP pin (active-high), software reset protocol recovery after bus interruption, and internally pulled-down A1/A2 pins when floating. The EEPROM uses an internal high-voltage pump for write operations and includes automatic self-timed write cycles (5 ms typical) with acknowledge polling support.

Key Specifications

Pinout & Package

AT24C1024BW-SH25-B is supplied in an 8-lead EIAJ SOIC package (package code 8S2), measuring 5.13–5.35 mm × 7.70–8.26 mm with 1.27 mm lead pitch. Pin 1 is marked by a notch or dot at the top-left corner.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT24C1024BN-SH25-B, AT24C1024BW-SH25-B offers wider EIAJ SOIC body for improved thermal dissipation in enclosed enclosures, while M95M01-RDW6TP trades I²C simplicity for SPI speed - neither is pin-compatible, and both require interface and layout adjustments.

Availability

AT24C1024BW-SH25-B is available at Aetrix Electronics and suitable for industrial PLC configuration storage, medical device calibration data retention, and smart energy meter firmware patching requiring stable component supply across extended production lifecycles.

Supply support for AT24C1024BW-SH25-B 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 acquired Atmel in 2016 and maintains full technical and manufacturing continuity for the AT24Cxx EEPROM family.

The AT24C1024BW-SH25-B belongs to Microchip's serial EEPROM product line, designed specifically for reliable, low-power nonvolatile storage in industrial, medical, and automotive systems where I²C bus efficiency and long-term data integrity are critical.

FAQ

What voltage range does the AT24C1024BW-SH25-B support?

The AT24C1024BW-SH25-B operates from 2.5V to 5.5V, making it compatible with both 3.3V and 5V logic systems. This dual-range capability eliminates the need for level shifters in mixed-voltage designs. The device is characterized across this full range for parameters including supply current, clock frequency, and input thresholds. AT24C1024BW-SH25-B does not support 1.8V operation - that variant is designated with "-SH-B" or "-SH-T" suffixes.

How many AT24C1024BW-SH25-B devices can share the same I²C bus?

Up to four AT24C1024BW-SH25-B devices can be connected to a single I²C bus using the A1 and A2 address pins. Each pin can be hardwired to VCC or GND, yielding four unique combinations (00, 01, 10, 11). When left floating, both pins default to logic low due to internal pull-downs, resulting in the base address. AT24C1024BW-SH25-B does not support dynamic address assignment or software-configurable addresses.

What is the maximum write speed for the AT24C1024BW-SH25-B?

The AT24C1024BW-SH25-B supports a maximum clock frequency of 1 MHz at 2.5V and 5V, enabling faster write transactions than the 400 kHz variant. However, the internal write cycle remains 5 ms typical regardless of clock speed - this is the time required for charge pumping and cell programming. So while address/data transfer occurs at 1 MHz, the device remains unresponsive during the 5 ms self-timed write. AT24C1024BW-SH25-B does not support accelerated write modes beyond page writes.

Does the AT24C1024BW-SH25-B have hardware write protection?

Yes, the AT24C1024BW-SH25-B includes a dedicated Write Protect (WP) pin that provides hardware-level write inhibition when driven high to VCC. This protects the entire memory array from accidental or malicious writes during normal operation. The WP pin is active-high and features internal pull-down logic when floating, defaulting to unprotected mode. AT24C1024BW-SH25-B also supports software write protection via specific command sequences, but hardware WP takes precedence.

What package type is used for the AT24C1024BW-SH25-B?

The AT24C1024BW-SH25-B uses an 8-lead EIAJ SOIC package (package code 8S2), which has a 0.209" body width - wider than JEDEC SOIC (8S1) but narrower than PDIP. Its dimensions are 5.13–5.35 mm × 7.70–8.26 mm with 1.27 mm lead pitch and NiPdAu lead finish. This package is RoHS-compliant and optimized for automated surface-mount assembly. AT24C1024BW-SH25-B is not available in TSSOP, dBGA2, or SAP variants - those use different suffixes (e.g., -TH25-B, -U4-UU-T).