Microchip Technology AT24C32E-U1UM0B-T

Overview

AT24C32E-U1UM0B-T from Microchip Technology is a 32-Kbit I²C-compatible serial EEPROM organized as 4,096 × 8 bits, operating from 1.7V to 3.6V with industrial temperature range (−40°C to +85°C), 1 MHz Fast Mode Plus support at 2.5–3.6V, and hardware write-protection via dedicated WP pin-used for firmware parameter storage in embedded controllers and sensor calibration data retention.

For engineers reviewing the AT24C32E-U1UM0B-T datasheet, AT24C32E-U1UM0B-T pinout, AT24C32E-U1UM0B-T application, or AT24C32E-U1UM0B-T equivalent, key selection criteria include low-voltage operation down to 1.7V, 32-byte page write capability with ≤5 ms self-timed write cycle, ultra-low standby current (0.8 µA max), Schmitt-triggered noise-immune I²C interface, and hardware write protection for critical configuration data.

Technical Context

The AT24C32E-U1UM0B-T implements a two-wire I²C interface with configurable device addressing via A0/A1/A2 pins, supporting Standard (100 kHz), Fast (400 kHz), and Fast Mode Plus (1 MHz) speeds across overlapping voltage ranges. Its internal architecture includes a 128-page × 32-byte memory array, hardware address comparator, high-voltage generation circuit for EEPROM programming, and integrated power-on reset (POR) with 100 µs tPUP delay.

Communication relies on open-drain SDA/SCL with external pull-ups, Schmitt-trigger inputs, and spike suppression filters. Write protection is implemented via a dedicated WP pin that disables all writes when pulled high, while floating WP defaults to GND via internal strong pull-down-ensuring fail-safe default behavior without external biasing.

Key Specifications

Pinout & Package

AT24C32E-U1UM0B-T is packaged in an 8-pad UDFN (2.0 mm × 1.6 mm, 0.5 mm pitch) with wettable flanks, optimized for automated optical inspection and high-density PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT24C32D-SSHM-T and M24C32-WMN6TP, the AT24C32E-U1UM0B-T delivers superior low-power performance (0.8 µA ISB), guaranteed Fast Mode Plus timing at 1 MHz, and a space-saving UDFN package-making it optimal for compact, battery-constrained, and noise-prone embedded systems requiring deterministic write cycles and robust data integrity.

Availability

AT24C32E-U1UM0B-T is available at Aetrix Electronics and suitable for industrial sensor calibration, medical device configuration, and automotive body control modules requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for AT24C32E-U1UM0B-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 Inc. is a leading provider of microcontroller, analog, FPGA, and memory solutions, serving industrial, automotive, communications, and consumer markets with vertically integrated silicon and development tools.

The AT24C32E-U1UM0B-T belongs to Microchip's AT24Cxx family of I²C serial EEPROMs, designed specifically for reliable, low-voltage, low-power nonvolatile data storage in space-constrained embedded systems requiring high endurance and long data retention.

FAQ

What is the maximum I²C clock frequency supported by the AT24C32E-U1UM0B-T?

The AT24C32E-U1UM0B-T supports 100 kHz (Standard Mode), 400 kHz (Fast Mode), and 1 MHz (Fast Mode Plus). The 1 MHz speed is guaranteed only at VCC = 2.5V to 3.6V per DS20006109B, making it suitable for high-throughput parameter updates in modern 3.3V systems. AT24C32E-U1UM0B-T does not support 1 MHz operation below 2.5V.

Does the AT24C32E-U1UM0B-T require external pull-up resistors on SDA and SCL lines?

Yes, AT24C32E-U1UM0B-T requires external pull-up resistors on both SDA and SCL lines because its I²C interface uses open-drain outputs. Recommended values are 10 kΩ for 100 kHz, 4 kΩ for 400 kHz, and 1.3 kΩ for 1 MHz operation-per Microchip's DS20006109B AC characteristics table. Failure to install appropriate pull-ups will result in communication failure.

How does the write-protect (WP) pin function on the AT24C32E-U1UM0B-T?

The WP pin on AT24C32E-U1UM0B-T is an active-high hardware lock: when pulled to VCC, it disables all write operations to the entire memory array. When left floating or tied to GND, writes are enabled. Internal strong pull-down ensures safe default behavior-no external resistor is mandatory, though Microchip recommends tying WP to a known state to prevent capacitive coupling issues in noisy environments.

What is the memory organization of the AT24C32E-U1UM0B-T?

The AT24C32E-U1UM0B-T organizes its 32,768 bits as 128 pages of 32 bytes each (4,096 × 8 bits total). This structure enables efficient 32-byte page writes, allowing partial updates within a page without erasing adjacent data-critical for preserving calibration constants or configuration flags during incremental firmware updates.

Is the AT24C32E-U1UM0B-T compatible with standard I²C protocol and address mapping?

Yes, AT24C32E-U1UM0B-T is fully I²C-compatible with a fixed 4-bit device type identifier (1010b) and 3-bit hardware address (A2/A1/A0), yielding 8 possible slave addresses (0x50–0x57). It adheres to I²C start/stop, ACK/NACK, and data stability timing requirements-including support for repeated start conditions-ensuring seamless integration with standard Linux i2c-tools, Arduino Wire, and RTOS-based drivers.