Microchip Technology AT24C1024B-TH-T

Overview

AT24C1024B-TH-T from Microchip Technology (formerly Atmel) is a 1 Mbit (131,072 × 8) two-wire serial EEPROM with 1.8V operation (1.8V–3.6V), 400 kHz clock rate at 1.8V, hardware write protection via WP pin, and 256-byte page write capability. It is used in industrial control modules for nonvolatile parameter storage where low-voltage operation and I²C bus compatibility are required.

For engineers reviewing the AT24C1024B-TH-T datasheet, AT24C1024B-TH-T pinout, AT24C1024B-TH-T application, or AT24C1024B-TH-T equivalent, key selection considerations include its TSSOP-8 package, 1.8V supply range, 400 kHz I²C speed at low voltage, 1,000,000 write endurance per page, and hardware/software write protection support.

Technical Context

The AT24C1024B-TH-T implements a standard two-wire (I²C-compatible) interface with open-drain SDA and Schmitt-triggered SCL inputs for noise immunity. Its internal address space is organized as 512 pages of 256 bytes each, requiring a 17-bit word address - with the most significant bit (P0) embedded in the device address byte.

It supports cascading up to four devices on one bus using A1/A2 address pins, enables software reset via protocol sequence, and features automatic address rollover during sequential reads/writes. Standby current is 1.0 µA at 1.8V, and write cycle time is 5 ms typical.

Key Specifications

Pinout & Package

AT24C1024B-TH-T is supplied in an 8-lead Thin Shrink Small Outline Package (TSSOP), 4.4 mm body width, NiPdAu lead finish. Pin 1 is marked by a dot at the top-left corner of the package bottom view.

Key Features

Applications

Equivalent & Alternatives

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

Compared with M95M01-RDW6TP and BR24G1M-3SER, AT24C1024B-TH-T offers guaranteed 400 kHz I²C operation at 1.8V with dedicated NC pin for layout flexibility, while maintaining industry-standard A1/A2 addressing for multi-device bus expansion - making it optimal for new 1.8V industrial designs requiring proven reliability and minimal protocol overhead.

Availability

AT24C1024B-TH-T is available at Aetrix Electronics and suitable for industrial sensor calibration storage, smart meter firmware parameter backup, and programmable logic controller (PLC) configuration requiring stable component supply and long-term obsolescence management.

Supply support for AT24C1024B-TH-T 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 product support, qualification, and documentation for the AT24C series EEPROMs.

The AT24C1024B-TH-T belongs to Microchip's serial EEPROM product line, designed specifically for robust, low-voltage, I²C-based nonvolatile data storage in industrial, automotive, and medical applications demanding high endurance and long data retention.

FAQ

What is the maximum I²C clock frequency supported by AT24C1024B-TH-T at 1.8V?

The AT24C1024B-TH-T supports a maximum I²C clock frequency of 400 kHz when operated at 1.8V. This is specified in the AC Characteristics table under "1.8-volt" conditions. At higher supply voltages (e.g., 2.5V or 5.0V), the device supports up to 1 MHz, but AT24C1024B-TH-T is rated for 1.8V–3.6V operation and thus operates at 400 kHz in its intended voltage range. This ensures timing margin and noise immunity in low-voltage systems.

Does AT24C1024B-TH-T support page write operations, and what is the page size?

Yes, AT24C1024B-TH-T supports page write operations with a fixed page size of 256 bytes. The device is internally organized into 512 pages of 256 bytes each. During a page write, up to 256 bytes can be written in a single I²C transaction, significantly reducing bus overhead compared to byte-wise writes. The AT24C1024B-TH-T automatically handles address incrementing within the page, and rollover occurs at the page boundary - a key feature confirmed in Section 6 of the datasheet.

How is write protection implemented on AT24C1024B-TH-T?

AT24C1024B-TH-T implements hardware write protection via the WP (Write Protect) pin: when WP is driven high to VCC, all write operations (byte, page, and erase) are inhibited. When WP is grounded, normal writes are enabled. If left floating, the pin is internally pulled down (subject to board capacitance), defaulting to unprotected mode. The AT24C1024B-TH-T also supports software write protection through internal register control, enabling layered security for critical configuration data.

What package type and lead finish does AT24C1024B-TH-T use?

AT24C1024B-TH-T uses an 8-lead Thin Shrink Small Outline Package (TSSOP) with a 4.4 mm body width and NiPdAu (Nickel-Palladium-Gold) lead finish. This is explicitly indicated by the "-TH-" prefix in the part number and confirmed in the Ordering Information table, where "8A2" maps to TSSOP. The NiPdAu finish provides excellent solderability, corrosion resistance, and wire-bond compatibility - critical for high-reliability industrial assembly.

Can multiple AT24C1024B-TH-T devices share the same I²C bus, and how is addressing managed?

Yes, up to four AT24C1024B-TH-T devices can share a single I²C bus using hardware address pins A1 and A2. These pins form the two least-significant bits of the 7-bit device address, allowing unique addressing (00, 01, 10, 11). The AT24C1024B-TH-T's device address prefix is fixed (1010xxx), with A1/A2 determining the final two bits. Floating A1/A2 pins default to logic low via internal biasing, enabling simple scalability without external resistors in basic configurations.