Microchip Technology AT24C32C-PU

Overview

AT24C32C-PU from Microchip Technology (formerly Atmel) is a 32 Kbit I²C-compatible serial EEPROM organized as 4096 × 8 bits, operating across 1.8 V to 5.5 V supply range, featuring hardware write protection via WP pin and 32-byte page write capability. It supports up to 1 MHz clock at 5.0 V and is widely used in industrial sensor calibration storage and embedded system configuration retention.

For engineers reviewing the AT24C32C-PU datasheet, AT24C32C-PU pinout, AT24C32C-PU application, or AT24C32C-PU equivalent, key selection considerations include its 8-lead PDIP package, 1 million write endurance, 100-year data retention, 400 kHz/1 MHz I²C speed grading, and hardware-based write protect functionality for secure nonvolatile parameter storage.

Technical Context

The AT24C32C-PU implements a standard two-wire I²C interface with open-drain SDA and Schmitt-triggered SCL inputs for noise immunity. Its internal address counter supports current-address, random-address, and sequential read modes, while cascading up to eight devices on one bus is enabled by three hardware-configurable device address pins (A0–A2).

Write operations are internally self-timed with a maximum 5 ms cycle time; acknowledge polling allows host firmware to detect completion without fixed delays. The device enters low-power standby mode after STOP condition or power-up, drawing only 1.0 µA at 1.8 V, making it suitable for battery-backed systems requiring persistent memory with minimal quiescent current.

Key Specifications

Pinout & Package

AT24C32C-PU is supplied in an 8-lead Plastic Dual Inline Package (PDIP), 0.300" wide, with through-hole mounting and industry-standard pin spacing. Pin 1 is marked by a dot or notch at the top-left corner of the package body.

Key Features

Applications

Equivalent & Alternatives

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

Compared with M24C32-WMN6TP and CAT24C32WI-GT3, the AT24C32C-PU provides broader package flexibility (including PDIP for prototyping), lower cost in bulk form, and proven reliability in long-lifecycle industrial designs - making it optimal for cost-sensitive, volume-manufactured equipment where extended temperature or ultra-fast reads are not mandatory.

Availability

AT24C32C-PU is available at Aetrix Electronics and suitable for industrial sensor calibration, embedded system configuration, and medical device settings requiring stable component supply and long-term obsolescence management.

Supply support for AT24C32C-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 a strong heritage in reliable nonvolatile memory products.

The AT24C32C-PU belongs to Microchip's AT24Cxx family of I²C serial EEPROMs, designed specifically for low-power, space-constrained embedded systems needing robust, long-life parameter storage without complex interface logic.

FAQ

What is the maximum I²C clock frequency supported by the AT24C32C-PU?

The AT24C32C-PU supports up to 1 MHz I²C clock frequency when operated at 5.0 V, and guarantees 400 kHz operation at the minimum 1.8 V supply. This dual-speed capability ensures interoperability with both legacy 400 kHz controllers and modern high-speed microcontrollers - a key advantage of the AT24C32C-PU in mixed-voltage system designs.

Does the AT24C32C-PU require external pull-up resistors on SDA and SCL lines?

Yes, the AT24C32C-PU requires external pull-up resistors on both SDA and SCL lines because its I/O pins are open-drain. Typical values range from 2.2 kΩ to 10 kΩ depending on bus capacitance and desired rise time; for a standard 100 pF bus at 400 kHz, 4.7 kΩ is commonly used - a requirement explicitly defined in the AT24C32C-PU electrical specifications.

How does the write protect (WP) pin function on the AT24C32C-PU?

When the WP pin of the AT24C32C-PU is driven HIGH to VCC, all write operations - including byte writes, page writes, and write-enable commands - are inhibited. When WP is LOW or floating (internally pulled down), normal write functionality is enabled. This hardware-level protection prevents unintended memory corruption during power transitions or firmware faults - a core safety feature of the AT24C32C-PU.

What is the endurance rating of the AT24C32C-PU, and how is it measured?

The AT24C32C-PU is rated for 1,000,000 write cycles per memory location, tested under standard conditions (25°C, 3.3 V, page-mode writes). This endurance applies to each individual byte address and is validated per JEDEC standards - meaning the AT24C32C-PU can sustain daily writes to the same location for over 27 years before potential failure, far exceeding typical industrial maintenance intervals.

Can multiple AT24C32C-PU devices share the same I²C bus?

Yes, up to eight AT24C32C-PU devices can operate on a single I²C bus using the A0, A1, and A2 address pins to configure unique 3-bit hardware addresses (0x50–0x57). This cascading capability eliminates bus arbitration complexity and enables modular system design - a defining architectural feature of the AT24C32C-PU that simplifies multi-sensor or multi-module architectures.