Microchip Technology AT24C512BW-SH25-B

Overview

AT24C512BW-SH25-B from Microchip Technology (formerly Atmel) is a 512 Kbit two-wire serial EEPROM organized as 65,536 × 8 bits, operating at 2.5V to 5.5V supply voltage, featuring 128-byte page write mode, hardware write protection via WP pin, and 1 MHz I²C bus compatibility at 2.5V/5.5V - used for firmware storage, calibration data retention, and configuration backup in industrial controllers and embedded instrumentation.

For engineers reviewing the AT24C512BW-SH25-B datasheet, AT24C512BW-SH25-B pinout, AT24C512BW-SH25-B application, or AT24C512BW-SH25-B equivalent, this page delivers verified package mapping (EIAJ SOIC-8), confirmed pin functions (A0–A2, SDA, SCL, WP, VCC, GND), endurance (1M cycles), data retention (40 years), and real-world timing specs including tWR = 5 ms max and AC characteristics per 2.5V operation.

Technical Context

The AT24C512BW-SH25-B implements a cascaded two-wire interface supporting up to eight devices on a shared I²C bus using three hardware address inputs (A0–A2). Its internal architecture includes a 16-bit address counter, Schmitt-triggered inputs with noise filtering, and open-drain bidirectional SDA with wire-OR capability.

It supports both byte and 128-byte page writes with self-timed internal write cycles, acknowledge polling for completion detection, and dual-voltage operation (2.5V–5.5V). The device enters low-power standby mode after STOP condition or power-up, drawing ≤6.0 µA at 5.5V.

Key Specifications

Pinout & Package

EIAJ SOIC-8 (8S2) package: 8-lead, 0.209" body width, gull-wing leads, RoHS-compliant NiPdAu lead finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT24C512BW-SH25-B, AT24C512BN-SH25-B offers identical functionality in a JEDEC-standard SOIC package, while M24512-RDW6TP trades 1 MHz performance for broader low-voltage support but limits system-level throughput in high-speed applications.

Availability

AT24C512BW-SH25-B is available at Aetrix Electronics and suitable for industrial automation, medical diagnostics, and automotive electronics requiring stable component supply, long-term data integrity, and drop-in replacement capability for legacy Atmel EEPROM designs.

Supply support for AT24C512BW-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 AT24C512BW-SH25-B belongs to Microchip's industrial-grade serial EEPROM product line, designed specifically for robust nonvolatile storage in harsh environments where reliability, long data retention, and I²C interoperability are critical.

FAQ

What is the maximum I²C clock frequency supported by the AT24C512BW-SH25-B?

The AT24C512BW-SH25-B supports up to 1 MHz I²C clock frequency when operated at 2.5V to 5.5V supply voltage. This is confirmed in Table 2-3 of the official datasheet (Rev. 5297A), where fSCL min/max values are specified as 1000 kHz for 2.5V/5.0V conditions. Operation at 1 MHz reduces firmware load time significantly compared to 400 kHz alternatives.

Does the AT24C512BW-SH25-B support partial page writes?

Yes, the AT24C512BW-SH25-B supports partial page writes within its 128-byte pages. As stated in the "Write Operations" section, the device accepts 1–128 bytes per page write sequence. The internal address counter increments automatically, and transmission of fewer than 128 bytes followed by STOP completes the operation without rolling over - enabling efficient storage of variable-length configuration records in the AT24C512BW-SH25-B.

What is the function of the WP pin on the AT24C512BW-SH25-B?

The WP (Write Protect) pin on the AT24C512BW-SH25-B provides hardware-level write inhibition. When pulled high to VCC, it disables all write operations to the entire memory array - preventing accidental or malicious overwrites. When grounded, full read/write access is enabled. The datasheet recommends tying WP to a known state (not floating) using ≤10 kΩ resistors to avoid noise-induced failures in industrial settings.

How many devices can share the same I²C bus with the AT24C512BW-SH25-B?

Up to eight AT24C512BW-SH25-B devices can share a single I²C bus using the three hardware address inputs A0, A1, and A2. Each combination of A0–A2 hardwired to GND or VCC generates a unique 3-bit device address, allowing distinct addressing within the standard 7-bit I²C protocol. This cascading capability simplifies multi-node sensor or actuator systems without requiring additional buses or muxes.

What package type is used for the AT24C512BW-SH25-B?

The AT24C512BW-SH25-B uses the EIAJ SOIC-8 package (ordering code suffix "W"), also designated as 8S2 in Atmel documentation. It features an 8-lead, 0.209" body width, gull-wing leads, and NiPdAu lead finish - distinct from the narrower JEDEC SOIC-8 (8S1) used in variants like AT24C512BN-SH25-B. Mechanical dimensions are fully specified in the 8S2 drawing (Rev. D, 4/7/06).