Microchip Technology AT24C64W-10SC-2.5

Overview

AT24C64W-10SC-2.5 from Microchip Technology (formerly Atmel) is a 64 Kbit (8192 × 8) I²C-compatible serial EEPROM optimized for low-voltage embedded systems. It operates from 2.5V to 5.5V, supports 100 kHz I²C bus speed at 2.5V, features hardware write protection via the WP pin, and delivers 1 million write cycles with 100-year data retention. It is commonly used in industrial sensor calibration storage and set-top box configuration memory.

For engineers reviewing the AT24C64W-10SC-2.5 datasheet, AT24C64W-10SC-2.5 pinout, AT24C64W-10SC-2.5 application, or AT24C64W-10SC-2.5 equivalent, key selection considerations include its 2.5V minimum supply, 8-pin SOIC package, page-write capability, Schmitt-trigger inputs for noise immunity, and compatibility with microcontroller I²C peripherals in space-constrained designs.

Technical Context

The AT24C64W-10SC-2.5 implements a standard two-wire I²C interface with open-drain SDA/SCL pins, supporting bidirectional data transfer and device addressing via A0–A2 pins. Its internal architecture organizes memory as 256 pages of 32 bytes each, enabling partial-page writes without erasing adjacent data.

It uses a proprietary input bias circuit on A0–A2 to default to logic low when floating, allowing up to eight devices on one bus. The WP pin provides hardware-level write protection for the upper quadrant (16K bits), and internal noise suppression filters ensure robust operation in electrically noisy environments.

Key Specifications

Pinout & Package

AT24C64W-10SC-2.5 is housed in an 8-pin JEDEC SOIC (SOIC-8, package code 8S1), measuring 3.9 mm × 4.9 mm × 1.75 mm, with gull-wing leads and 1.27 mm pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with M24C64-WMN6TP and BR24G64FJ-3GE2, the AT24C64W-10SC-2.5 offers proven interoperability with legacy Atmel-based designs, simpler hardware write protection via dedicated WP pin, and broader design documentation support - making it ideal for cost-sensitive industrial control upgrades where layout reuse is critical.

Availability

AT24C64W-10SC-2.5 is available at Aetrix Electronics and suitable for industrial sensor calibration, set-top box configuration storage, and smart meter firmware parameter retention requiring stable component supply and long-term lifecycle assurance.

Supply support for AT24C64W-10SC-2.5 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, delivering high-reliability nonvolatile memory solutions since 1980.

The AT24C64W-10SC-2.5 belongs to Microchip's serial EEPROM product line, engineered specifically for low-power, space-constrained embedded systems requiring robust, pin-compatible memory expansion with minimal firmware overhead.

FAQ

What is the maximum I²C clock frequency supported by AT24C64W-10SC-2.5 at 2.5V?

The AT24C64W-10SC-2.5 supports a maximum I²C clock frequency of 100 kHz when operating at 2.5V. This is specified in the AC Characteristics table under "2.7-, 2.5-volt" column for fSCL. At 5.0V, the device supports up to 400 kHz, but the 2.5V variant is strictly rated for 100 kHz to ensure timing margin and signal integrity under low-voltage conditions. This value is confirmed in the AT24C32/64 datasheet Rev. 0336F–08/98, page 4.

Does AT24C64W-10SC-2.5 require external pull-up resistors on SDA and SCL lines?

Yes, AT24C64W-10SC-2.5 requires external pull-up resistors on both SDA and SCL lines because its I²C interface uses open-drain outputs. Typical values range from 2.2 kΩ to 10 kΩ depending on bus capacitance and speed; 4.7 kΩ is recommended for 100 kHz operation with ≤400 pF total bus capacitance. This requirement is explicitly stated in the "Bus Timing" and "Device Operation" sections of the datasheet.

How many devices can share the same I²C bus with AT24C64W-10SC-2.5?

Up to eight AT24C64W-10SC-2.5 devices can share a single I²C bus, enabled by the three hardware address pins A0, A1, and A2. Each pin can be tied high, low, or left floating (internally pulled low), yielding 2³ = 8 unique 7-bit device addresses (0x50–0x57). This cascading capability is documented in the "Device Addressing" section and block diagram of the AT24C32/64 datasheet.

What memory organization does AT24C64W-10SC-2.5 use, and how does it affect write operations?

AT24C64W-10SC-2.5 organizes its 64 Kbit memory as 256 pages of 32 bytes each. This structure enables 32-byte page writes: writing beyond a page boundary causes automatic rollover to the start of the same page, not the next page. Partial-page writes are allowed, but crossing page boundaries requires separate write commands. This behavior is defined in the "Write Operations" and "Memory Organization" sections of the datasheet.

Is AT24C64W-10SC-2.5 qualified for automotive applications?

No, AT24C64W-10SC-2.5 is rated for the commercial temperature range (0°C to +70°C) and is not automotive-qualified. Automotive-grade variants (e.g., AT24C64D-SSHM-T) exist with extended temperature range (−40°C to +125°C) and AEC-Q100 qualification, but the -10SC-2.5 suffix indicates SOIC-8 packaging and commercial operation. This distinction is clearly shown in the "AT24C64 Ordering Information" tables on pages 12–13 of the datasheet.