Microchip Technology AT24C02B-PU

Overview

AT24C02B-PU from Microchip Technology (formerly Atmel) is a 2K-bit (256 × 8) two-wire serial EEPROM with I²C-compatible interface, operating from 1.8 V to 5.5 V, featuring hardware write protection via WP pin, 1 MHz max clock speed at 5 V, and 8-byte page write capability. It is used for nonvolatile parameter storage in embedded controllers, power supplies, and industrial sensors requiring low-voltage operation and long data retention.

For engineers reviewing the AT24C02B-PU datasheet, AT24C02B-PU pinout, AT24C02B-PU application, or AT24C02B-PU equivalent, key selection considerations include its PDIP-8 package, 1.8–5.5 V supply range, 100-year data retention, 1 million write cycles, and compatibility with standard I²C bus timing at 400 kHz (1.8 V) and 1 MHz (5 V).

Technical Context

The AT24C02B-PU implements a standard I²C protocol with open-drain SDA/SCL lines, Schmitt-triggered inputs for noise immunity, and addressable device addressing using A0–A2 pins. It supports byte and 8-byte page writes with self-timed internal write cycles up to 5 ms.

Its memory is organized as 32 pages of 8 bytes each, enabling partial-page writes without rollover beyond page boundaries. The WP pin provides hardware-level write protection-asserting it high disables all write operations across the full 2K array.

Key Specifications

Pinout & Package

AT24C02B-PU is supplied in an 8-lead PDIP (Plastic Dual Inline Package), 0.300" wide body, with through-hole mounting and industry-standard pin spacing. Pin 1 is marked by a dot on the top surface.

Key Features

Applications

Equivalent & Alternatives

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

Compared with M24C02-RMN6TP and BR24G02NUX-10, the AT24C02B-PU offers hardware-based write protection and explicit A0–A2 addressing-critical for multi-node I²C systems where deterministic, fail-safe data integrity is mandatory.

Availability

AT24C02B-PU is available at Aetrix Electronics and suitable for industrial sensor calibration, smart power supply configuration, and embedded controller boot parameter storage requiring stable component supply and long-lifecycle support.

Supply support for AT24C02B-PU 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 is a global semiconductor company specializing in microcontrollers, analog devices, and memory solutions, with broad industrial and automotive qualification capabilities.

The AT24C02B-PU belongs to Microchip's legacy serial EEPROM product line, designed specifically for cost-sensitive, low-power embedded systems requiring robust nonvolatile storage with minimal external components and I²C bus compatibility.

FAQ

What is the maximum I²C clock frequency supported by the AT24C02B-PU?

The AT24C02B-PU supports up to 1 MHz at VCC = 5.0 V and 400 kHz at VCC = 1.8 V, 2.5 V, or 2.7 V. These values are specified under standard load conditions (CL = 100 pF). Exceeding these frequencies may result in timing violations or unreliable communication. The AT24C02B-PU does not support fast-mode plus (1 MHz universal) or high-speed mode (3.4 MHz) without external signal conditioning.

Does the AT24C02B-PU require external pull-up resistors on SDA and SCL lines?

Yes, the AT24C02B-PU requires external pull-up resistors on both SDA and SCL lines because its I/O pins are open-drain. Typical values range from 1.8 kΩ (for 1 MHz, 5 V) to 10 kΩ (for 100 kHz, 1.8 V), depending on bus capacitance and speed requirements. The AT24C02B-PU itself does not integrate internal pull-ups.

Can the AT24C02B-PU be used in automotive applications?

No - the AT24C02B-PU is rated for industrial temperature range (–40 °C to +85 °C) and is not qualified to AEC-Q100 standards. While some variants like AT24C02BN-SH-B are offered in automotive-grade packages, the AT24C02B-PU specifically is intended for commercial and industrial use only.

How many devices can share the same I²C bus with the AT24C02B-PU?

Up to eight AT24C02B-PU devices can be addressed on a single I²C bus using the A0, A1, and A2 address pins. Each combination of hard-wired A0–A2 yields a unique 3-bit device address, enabling concurrent operation without software arbitration. The AT24C02B-PU's fixed 7-bit base address (1010xxx) ensures compatibility within this addressing scheme.

What happens during an AT24C02B-PU write cycle, and how should the host controller handle it?

During an AT24C02B-PU write cycle, all inputs are disabled and the device does not respond to I²C commands until internal programming completes (≤5 ms). The host must either wait the maximum time or use acknowledge polling: send a START + device address with R/W = 0; if the AT24C02B-PU responds with ACK, the write is complete. This ensures deterministic timing without fixed delays.