Microchip Technology AT24C32E-UUM0B-T

Overview

AT24C32E-UUM0B-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 WP pin-used for configuration storage in embedded controllers and sensor calibration data retention.

For engineers reviewing the AT24C32E-UUM0B-T datasheet, AT24C32E-UUM0B-T pinout, AT24C32E-UUM0B-T application, or AT24C32E-UUM0B-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), I²C bus address flexibility (A0–A2 inputs), and RoHS-compliant 8-pad UDFN packaging.

Technical Context

The AT24C32E-UUM0B-T implements a two-wire I²C interface with Schmitt-triggered, noise-filtered SCL/SDA inputs and open-drain bidirectional SDA. It supports Standard (100 kHz), Fast (400 kHz), and Fast Mode Plus (1 MHz) timing across defined VCC ranges, with automatic address decoding using A0–A2 pins and hardware-based full-array write protection via the WP pin.

Internally organized as 128 pages of 32 bytes, it enables partial page writes and supports random/sequential read modes. Its Power-on Reset (POR) circuit enforces tPUP ≥ 100 µs after stable VCC, and its EEPROM array guarantees 1,000,000 write cycles and 100-year data retention at 55°C.

Key Specifications

Pinout & Package

AT24C32E-UUM0B-T is packaged in an 8-pad UDFN (Ultra Thin Dual Flat No-lead) with wettable flanks, measuring 2.0 mm × 1.6 mm × 0.55 mm, optimized for automated optical inspection (AOI) 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, AT24C32E-UUM0B-T delivers 2.5× faster configuration loading via 1 MHz FM+ and 2.5× lower standby current-key for battery longevity. Versus M24C32-WMN6TP, AT24C32E-UUM0B-T offers tighter low-VCC operation (1.7V vs. 2.5V min) and superior leakage performance, making it optimal for ultra-low-power 1.8V SoC integration.

Availability

AT24C32E-UUM0B-T is available at Aetrix Electronics and suitable for industrial sensor nodes, medical wearables, automotive body controllers, and smart home hubs requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for AT24C32E-UUM0B-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 is a leading provider of microcontrollers, analog components, and memory solutions, with core expertise in embedded control and secure connectivity.

The AT24C32E series belongs to Microchip's serial EEPROM product line, designed specifically for reliable, low-power, I²C-based nonvolatile storage in space- and energy-constrained embedded systems.

FAQ

What is the maximum I²C clock frequency supported by the AT24C32E-UUM0B-T?

The AT24C32E-UUM0B-T supports 100 kHz (Standard Mode), 400 kHz (Fast Mode), and 1 MHz (Fast Mode Plus). The 1 MHz mode requires VCC between 2.5V and 3.6V. This allows faster configuration reads in time-critical applications while maintaining compatibility with legacy 100 kHz buses. All timing parameters-including tLOW, tHIGH, and tSU.DAT-are fully specified in the DS20006109B datasheet for each mode.

Does the AT24C32E-UUM0B-T require external pull-up resistors on SDA and SCL lines?

Yes, the AT24C32E-UUM0B-T requires external pull-up resistors on both SDA and SCL lines because both pins are open-drain. Microchip specifies maximum values of 10 kΩ for 100 kHz, 4 kΩ for 400 kHz, and 1.3 kΩ for 1 MHz operation, based on bus capacitance (CL = 100 pF). Failure to install appropriate pull-ups will result in communication failure or intermittent bus hangs.

How does the write-protect (WP) pin function on the AT24C32E-UUM0B-T?

The WP pin on the AT24C32E-UUM0B-T is an active-high hardware lock: when tied to VCC, it inhibits all write operations to the entire memory array; when tied to GND, normal writes are enabled. If left floating, the internal weak pull-down defaults it to GND-enabling writes-but Microchip recommends explicit biasing to avoid noise-induced glitches. This feature provides deterministic, hardware-level data integrity independent of firmware state.

What is the memory organization of the AT24C32E-UUM0B-T, and how does it affect page writes?

The AT24C32E-UUM0B-T is organized as 128 pages of 32 bytes each (total 4,096 × 8 bits). Page write mode allows up to 32 bytes to be written in a single I²C transaction, provided all addresses fall within the same 32-byte boundary. Crossing a page boundary terminates the write and wraps to the start of the page-so partial-page writes are safe, but multi-page updates require separate transactions. This structure balances speed and data safety in firmware update routines.

Is the AT24C32E-UUM0B-T compatible with standard I²C protocol stacks and drivers?

Yes, the AT24C32E-UUM0B-T is fully compliant with the NXP I²C-bus specification, supporting standard Start/Stop conditions, ACK/NACK handshaking, 7-bit addressing (with fixed '1010' prefix and A2–A0 bits), and repeated Start sequences. It requires no custom drivers-standard HAL or bare-metal I²C implementations (e.g., STM32 HAL_I2C_Mem_Write, Arduino Wire library) work out-of-the-box, provided timing constraints (e.g., tSU.STA, tHD.DAT) are met in the host controller's configuration.