Microchip Technology AT25HP256W-10SI

Overview

AT25HP256W-10SI from Atmel (now Microchip) is a 256 Kbit serial SPI EEPROM organized as 32,768 × 8-bit memory, operating at 2.7V–5.5V supply, supporting up to 5 MHz clock frequency in 2.7V mode, with 100K write endurance and >40-year data retention. It serves as nonvolatile configuration storage in industrial microcontroller systems requiring robust, low-voltage, page-write-capable memory.

For engineers reviewing the AT25HP256W-10SI datasheet, AT25HP256W-10SI pinout, AT25HP256W-10SI application, or AT25HP256W-10SI equivalent, this device delivers verified SPI Mode 0/3 compatibility, hardware/software write protection (WP/HOLD pins + status register), 128-byte page write capability, and industrial temperature support (−40°C to +85°C) in an 8-pin EIAJ SOIC package.

Technical Context

The AT25HP256W-10SI implements a synchronous slave SPI interface with dedicated SI (input), SO (output), SCK (clock), and CS (chip select) lines - no separate erase cycle required. Its internal architecture includes a nonvolatile status register controlling block write protection (BP0/BP1 bits) and write protect enable (WPEN), with all programming self-timed and fully compliant with 6800-series microcontroller SPI timing.

It supports three voltage ranges (1.8V, 2.7V, 5.0V), but the AT25HP256W-10SI variant is specifically rated for 2.7V–5.5V operation with 5 MHz max SCK frequency and 10 ms typical write cycle time. The HOLD pin enables mid-sequence suspension without resetting the serial interface, while WP provides hardware-level inhibition of status register writes when WPEN = 1.

Key Specifications

Pinout & Package

AT25HP256W-10SI is packaged in an 8-pin EIAJ SOIC (package code 8S2), 0.300" wide, surface-mount gull-wing format with standard JEDEC footprint and 1.27 mm pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with M95256-WDW6TP and BR25H256FJ-2CE2, the AT25HP256W-10SI uniquely combines HOLD pin support, hardware WP, industrial temperature rating, and exact 8-pin EIAJ SOIC compatibility - making it optimal for deterministic, safety-aware embedded systems where transaction integrity and drop-in replacement matter.

Availability

AT25HP256W-10SI is available at Aetrix Electronics and suitable for industrial control systems, medical instrumentation, smart energy meters, and automotive body electronics requiring stable component supply across extended product lifecycles.

Supply support for AT25HP256W-10SI 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

Atmel Corporation, now part of Microchip Technology, is a semiconductor manufacturer specializing in microcontrollers, nonvolatile memory, and secure authentication ICs for industrial, automotive, and consumer markets.

The AT25HP256W-10SI belongs to Atmel's high-reliability SPI EEPROM product line, designed specifically for industrial and commercial applications demanding low-voltage operation, fast write performance, and robust data integrity under thermal stress.

FAQ

What voltage range does the AT25HP256W-10SI support, and is it compatible with 3.3V microcontrollers?

The AT25HP256W-10SI operates from 2.7V to 5.5V, making it fully compatible with standard 3.3V logic systems. Its VIH threshold is VCC × 0.7 (min), so at 3.3V it accepts ≥2.31V as high - well within typical 3.3V MCU output swing. VOH is VCC − 0.2V (min), ensuring reliable high-level signaling back to the host. No level shifting is required when interfacing with 3.3V SPI masters.

Does the AT25HP256W-10SI require a separate erase command before writing new data?

No, the AT25HP256W-10SI does not require a separate erase command. All write operations - including page writes - are self-timed and automatically erase and program the target memory location internally. The device powers up in write-disabled state, so each write sequence must begin with a WREN (Write Enable) instruction, followed by WRITE op-code, address, and data - then CS high to initiate the internal 10 ms write cycle.

How does the HOLD pin function on the AT25HP256W-10SI, and what is its timing requirement?

The HOLD pin on the AT25HP256W-10SI suspends ongoing SPI communication without resetting the internal address counter or byte alignment. To activate HOLD, the pin must be driven low while SCK is low; to resume, it must be returned high while SCK remains low. During HOLD, SI is ignored and SO enters high-impedance - allowing the host MCU to service interrupts or perform other tasks before continuing the exact same transaction.

Can the AT25HP256W-10SI be used in automotive applications, and what qualifications does it hold?

The AT25HP256W-10SI is rated for industrial temperature (−40°C to +85°C) and meets JEDEC JESD47 reliability standards, but it is not AEC-Q100 qualified. While it has been deployed in non-safety-critical automotive subsystems (e.g., infotainment settings storage), it is not approved for engine control, ADAS, or airbag systems. For automotive-grade alternatives, consider AEC-Q100-certified parts like the BR25H256FJ-2CE2 or M95M02-DWDW3TP.

What is the maximum supported SPI clock frequency for the AT25HP256W-10SI at 2.7V, and how is timing validated?

At 2.7V supply, the AT25HP256W-10SI supports up to 5 MHz SCK frequency. This is validated by AC specifications: tWH and tWL minimums are 80 ns each, implying a 200 ns period (5 MHz). Setup (tSU = 20 ns) and hold (tH = 20 ns) times are also guaranteed across −40°C to +85°C, ensuring robust timing margins even under worst-case voltage and temperature conditions.