Microchip Technology AT25M02-U1UM0B-T

Overview

AT25M02-U1UM0B-T from Microchip Technology is a 2 Mbit SPI Serial EEPROM (262,144 × 8) in an 8-ball WLCSP package, supporting 1.7V–5.5V operation, 5 MHz clock rate at 5V, and industrial temperature range (−40°C to +85°C). It features hardware/software write protection, 256-byte page writes, and 1,000,000 write endurance for firmware storage in space-constrained embedded controllers.

For engineers reviewing the AT25M02-U1UM0B-T datasheet, AT25M02-U1UM0B-T pinout, AT25M02-U1UM0B-T application, or AT25M02-U1UM0B-T equivalent, key selection criteria include low-voltage SPI compatibility, block-level write protection granularity (1/4, 1/2, or full array), HOLD/CS timing behavior, and WLCSP thermal/mechanical integration in portable or automotive control modules.

Technical Context

The AT25M02-U1UM0B-T implements a standard SPI slave interface with support for Modes 0 and 3, latching input on SCK rising edge and outputting data on falling edge. Its internal architecture includes a high-voltage generation circuit for EEPROM programming, a STATUS register with nonvolatile BP1/BP0 bits for configurable block protection, and a dedicated HOLD pin that suspends serial communication without resetting the instruction sequence.

Write operations are self-timed with ≤10 ms maximum cycle time and use internal polling via RDY/BSY bit; the device enters standby mode with ≤1.0 µA current at 1.8V when CS is high. Power-on reset ensures stable initialization, requiring ≥100 µs delay after VCC stabilization before first command.

Key Specifications

Pinout & Package

AT25M02-U1UM0B-T uses an 8-ball WLCSP (Wafer-Level Chip Scale Package) with 0.4 mm pitch, designed for minimal PCB footprint and high-density routing in portable electronics.

Key Features

Applications

Equivalent & Alternatives

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

Compared with M95M02-DFMN6TP and BR25M02FJ-WE2, the AT25M02-U1UM0B-T delivers the lowest standby current and most flexible hardware/software write protection in the smallest package-making it optimal for miniaturized, battery-constrained, or safety-critical applications where memory integrity and size are primary constraints.

Availability

AT25M02-U1UM0B-T is available at Aetrix Electronics and suitable for industrial sensor nodes, automotive body control modules, and medical infusion pumps requiring stable component supply, long-term lifecycle support, and RoHS-compliant WLCSP packaging.

Supply support for AT25M02-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 microcontrollers, analog components, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The AT25M02-U1UM0B-T belongs to Microchip's AT25 family of SPI EEPROMs, engineered for robust, low-power nonvolatile storage in space- and power-constrained embedded systems across automotive, industrial, and medical markets.

FAQ

What is the maximum clock frequency supported by the AT25M02-U1UM0B-T?

The AT25M02-U1UM0B-T supports a maximum SPI clock frequency of 5 MHz when operating at VCC = 5.0V. At lower supply voltages (e.g., 1.8V), the maximum rated clock speed is reduced per AC characteristics in the datasheet; design margins should account for timing parameters like tWH/tWL (≥80 ns) and setup/hold times (≥20 ns) to ensure reliable communication across voltage and temperature ranges. The AT25M02-U1UM0B-T does not auto-negotiate speed and relies on host-controlled clock generation.

Does the AT25M02-U1UM0B-T support both SPI Mode 0 and Mode 3 simultaneously?

Yes, the AT25M02-U1UM0B-T supports both SPI Mode 0 (CPOL = 0, CPHA = 0) and Mode 3 (CPOL = 1, CPHA = 1), but only one mode may be used per communication session. The device requires consistent SCK idle polarity before and after CS assertion-switching modes mid-operation will cause framing errors. Mode selection is determined by the host controller; the AT25M02-U1UM0B-T does not detect or adapt to mode changes dynamically.

How does the HOLD pin function during an active write cycle in the AT25M02-U1UM0B-T?

The HOLD pin in the AT25M02-U1UM0B-T has no effect on an ongoing internal write cycle (e.g., after WRITE or WRSR command initiation); the operation continues to completion even if HOLD is asserted. HOLD only suspends serial data transfer-input sampling and output driving-while preserving the internal state machine. Once deasserted, the device resumes normal SPI communication from the exact point of suspension, but the write cycle itself is unaffected and cannot be paused or aborted via HOLD.

What is the factory default state of the STATUS register in the AT25M02-U1UM0B-T?

At shipment, the AT25M02-U1UM0B-T has the STATUS register initialized with WPEN = 0, BP1 = 0, BP0 = 0, WEL = 0, and RDY/BSY = 0. This configures no block protection (full array writable), disables hardware write protection via WP pin, and sets the device to ready/idle state. The EEPROM array itself contains all 0xFFh bytes. These defaults are nonvolatile and persist across power cycles unless explicitly modified via WRSR or WRITE commands.

Can the AT25M02-U1UM0B-T be used in a 1.8V-only system without level shifting?

Yes, the AT25M02-U1UM0B-T is fully compatible with 1.8V-only systems: its low-voltage grade supports VCC = 1.7V to 5.5V, input thresholds scale with VCC (VIH ≥ 0.7×VCC, VIL ≤ 0.3×VCC), and DC/AC specs-including 5 MHz operation-are validated down to 1.8V. No level shifting is required when interfacing with 1.8V microcontrollers, provided timing margins (e.g., tSU/tH ≥20 ns) are met and PCB routing minimizes capacitive loading on SI/SO lines.