Microchip Technology AT25M02-SSHM-B

Overview

AT25M02-SSHM-B from Microchip Technology is a 2 Mbit SPI Serial EEPROM (262,144 × 8) in an 8-lead SOIC 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 nonvolatile data storage in microcontroller-based systems.

For engineers reviewing the AT25M02-SSHM-B datasheet, AT25M02-SSHM-B pinout, AT25M02-SSHM-B application, or AT25M02-SSHM-B equivalent, key selection criteria include SPI Mode 0/3 compatibility, WP/HOLD pin functionality, block protection granularity (1/4, 1/2, full array), self-timed 10 ms max write cycle, and green RoHS-compliant packaging.

Technical Context

The AT25M02-SSHM-B implements a synchronous SPI slave interface with fixed MSB-first data framing, rising-edge input sampling on SI, and falling-edge output valid on SO. Its internal architecture includes a high-voltage generation circuit for EEPROM programming, a STATUS register with nonvolatile BP1/BP0 and WPEN bits, and dedicated control logic for HOLD suspension and WP-enforced write inhibition.

It supports dual voltage grades (1.7V–5.5V low-voltage and 2.5V–5.5V standard-voltage), operates across −40°C to +85°C, and integrates Power-on Reset (POR) with 100 µs tPUP delay and 1.5 V VPOR threshold to prevent spurious writes during power-up sequences.

Key Specifications

Pinout & Package

AT25M02-SSHM-B is packaged in an 8-lead SOIC (Small Outline Integrated Circuit) with standard JEDEC MS-012AC footprint (5.3 mm × 6.2 mm, 1.27 mm pitch), suitable for reflow soldering and automated optical inspection.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT25M02-SSHM-B, AT25DF041A-SSH-T trades byte-level write flexibility for higher density and lower cost per bit in code storage roles, while M95M02-DRMN6TP/K offers functional equivalence with minor register-level differences requiring firmware review.

Availability

AT25M02-SSHM-B is available at Aetrix Electronics and suitable for industrial PLCs, medical diagnostics equipment, automotive body control modules, and smart energy metering systems requiring stable component supply across multi-year production cycles.

Supply support for AT25M02-SSHM-B 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 manufacturer specializing in microcontrollers, analog devices, and memory solutions, with ISO 9001-certified global manufacturing and design centers.

The AT25M02-SSHM-B belongs to Microchip's AT25 family of SPI Serial EEPROMs, engineered for low-power, high-reliability nonvolatile data storage in resource-constrained embedded systems where byte-addressable writes and long data retention are mandatory.

FAQ

What is the maximum SPI clock frequency supported by the AT25M02-SSHM-B?

The AT25M02-SSHM-B supports up to 5 MHz SPI clock frequency at VCC = 5.0V. At lower supply voltages (e.g., 1.8V), the maximum rated clock frequency remains 5 MHz per AC specifications, though actual achievable speed may depend on signal integrity and load capacitance. The device complies with SPI Modes 0 and 3, with data latched on rising SCK and output on falling SCK edges.

Does the AT25M02-SSHM-B require external pull-up resistors on its control pins?

Yes - the AT25M02-SSHM-B requires a pull-up resistor (≤10 kΩ) on the CS pin to ensure robust power-up behavior and prevent spurious commands. The WP and HOLD pins also benefit from defined logic states (typically pulled high via 10 kΩ) when not actively driven, especially in noisy industrial environments. SO is internally tri-stated and does not require a pull-up.

How does write protection work on the AT25M02-SSHM-B?

AT25M02-SSHM-B implements dual-layer write protection: hardware-based via the WP pin (active-low, effective only when WPEN = 1 in STATUS register) and software-based via BP1/BP0 bits that lock 0%, 25%, 50%, or 100% of the memory array. WP can interrupt STATUS register writes mid-command, but has no effect once internal programming begins. WPEN = 0 disables WP pin functionality entirely.

What is the purpose of the HOLD pin on the AT25M02-SSHM-B?

The HOLD pin on AT25M02-SSHM-B suspends ongoing SPI communication without resetting the transaction state - useful when the host MCU must service a higher-priority interrupt. HOLD must be asserted during an SCK low period; SO enters high-impedance, and SI/SCK are ignored until HOLD is deasserted (also during SCK low). HOLD does not affect active internal write cycles.

Is the AT25M02-SSHM-B RoHS compliant and lead-free?

Yes - the AT25M02-SSHM-B is RoHS compliant, lead-free, and halide-free per Microchip's green packaging policy. The "-B" suffix in the part number explicitly denotes compliance with EU RoHS Directive 2011/65/EU and related restrictions on hazardous substances. Full material declarations and certificate of compliance are available from Microchip upon request.