Microchip Technology AT25M02-SSHD-T

Overview

AT25M02-SSHD-T from Microchip Technology is a 2 Mbit SPI Serial EEPROM (262,144 × 8) optimized for low-voltage industrial applications. It operates from 1.7V to 5.5V, supports 5 MHz clock rate at 5V, features 256-byte page write mode, and delivers 1,000,000 write cycles with 100-year data retention - deployed in embedded systems requiring nonvolatile configuration storage.

For engineers reviewing the AT25M02-SSHD-T datasheet, AT25M02-SSHD-T pinout, AT25M02-SSHD-T application, or AT25M02-SSHD-T equivalent, key selection criteria include SPI Mode 0/3 compatibility, hardware/software write protection via WP/HOLD pins, industrial temperature range (–40°C to +85°C), and SOIC-8 package footprint suitability for space-constrained PCBs.

Technical Context

The AT25M02-SSHD-T implements a synchronous SPI slave interface with fixed MSB-first data framing, rising-edge input sampling on SI, and falling-edge output driving on SO. Its internal architecture includes a high-voltage generation circuit for EEPROM programming, a STATUS register with nonvolatile BP1/BP0 block protection bits, and a Power-on Reset (POR) circuit ensuring stable initialization at VCC ≥ 1.5 V.

It supports dual voltage grades (1.7–5.5 V low-voltage and 2.5–5.5 V standard-voltage), uses a self-timed write cycle ≤ 10 ms, and provides hardware hold functionality via the HOLD pin - active only when CS is asserted and SCK is low - enabling pause/resume of ongoing serial transfers without resetting the command sequence.

Key Specifications

Pinout & Package

AT25M02-SSHD-T is supplied in an 8-lead SOIC package (SOIC-8, 150 mil width), with pin 1 marked by a notch or dot. The package is RoHS-compliant, halide-free, and lead-free.

Key Features

Applications

Equivalent & Alternatives

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

Compared with M95M02-DRMN6TP/K and BR25M02FJ-WE2, the AT25M02-SSHD-T uniquely supports 1.7 V operation while maintaining industrial temperature rating and offering flexible block protection - making it optimal for mixed-voltage, battery-sensitive designs where voltage headroom is constrained.

Availability

AT25M02-SSHD-T is available at Aetrix Electronics and suitable for industrial PLCs, medical diagnostics equipment, automotive body control modules, and smart energy meters requiring stable component supply across extended product lifecycles.

Supply support for AT25M02-SSHD-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 U.S.-based semiconductor company specializing in microcontrollers, analog devices, and memory solutions, with a focus on reliability, longevity, and industrial-grade qualification.

The AT25M02-SSHD-T belongs to Microchip's AT25 family of SPI Serial EEPROMs, designed specifically for robust, low-power nonvolatile storage in harsh environments where data integrity and long-term retention are mission-critical.

FAQ

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

The AT25M02-SSHD-T supports up to 5 MHz SPI clock frequency at VCC = 5.0 V. At lower supply voltages (e.g., 1.8 V), the maximum clock rate is reduced per AC characteristics in the datasheet; design margin should be applied for reliable operation across voltage and temperature extremes. The AT25M02-SSHD-T does not support 10 MHz or higher clocks - that capability is found only in newer family members like the AT25SF041.

Does the AT25M02-SSHD-T support SPI Mode 1 or Mode 2?

No, the AT25M02-SSHD-T supports only SPI Modes 0 (CPOL = 0, CPHA = 0) and 3 (CPOL = 1, CPHA = 1). It does not support Mode 1 or Mode 2 because its input sampling and output timing are fixed to rising-edge capture and falling-edge output - incompatible with CPHA = 1 sampling on SCK edges. This limitation is explicitly stated in the "Features" section of the AT25M02-SSHD-T datasheet.

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

The HOLD pin has no effect on an ongoing internal write cycle in the AT25M02-SSHD-T. While HOLD can suspend serial communication (e.g., mid-read or mid-command), it does not interrupt or delay the self-timed 10 ms write operation once initiated. The device continues programming the EEPROM array regardless of HOLD state - ensuring data integrity even if host communication is paused. This behavior is documented in Section 5.3 of the AT25M02-SSHD-T datasheet.

Can the AT25M02-SSHD-T be used with a 1.8 V microcontroller without level shifting?

Yes, the AT25M02-SSHD-T is fully compatible with 1.8 V microcontrollers: its VCC range includes 1.7–5.5 V, VIH min is VCC × 0.7 (so ~1.26 V at 1.8 V), and VOL max is 0.2 V - well within 1.8 V logic thresholds. No level shifter is required when interfacing with 1.8 V MCUs, provided VCC is supplied at 1.8 V and all SPI signals share the same ground reference. This interoperability is confirmed in Table 4-2 (DC Characteristics) of the AT25M02-SSHD-T datasheet.

What happens to the STATUS register after power-up of the AT25M02-SSHD-T?

At power-up, the AT25M02-SSHD-T initializes with WEL = 0 (write disabled), RDY/BSY = 0 (ready), and WPEN/BP1/BP0 retaining their last written nonvolatile values - meaning block protection settings persist across power cycles. The device enters Standby mode and requires a CS low transition before accepting commands. This default state is defined in Section 4.6.1.5 of the AT25M02-SSHD-T datasheet and ensures safe, predictable startup behavior.