Microchip Technology 25AA020A-I/SN

Overview

25AA020A-I/SN from Microchip Technology Inc. is a 2 Kbit (256 × 8) SPI serial EEPROM with 1.8–5.5 V supply range, 10 MHz max clock frequency, and industrial temperature rating (−40°C to +85°C). It features write page mode (16-byte pages), hardware write-protection via WP pin, and HOLD functionality for interrupt-safe bus suspension. It is used in embedded systems for storing calibration data, configuration settings, and firmware parameters.

For engineers reviewing the 25AA020A-I/SN datasheet, 25AA020A-I/SN pinout, 25AA020A-I/SN application, or 25AA020A-I/SN equivalent, key selection criteria include SPI interface compatibility, low-voltage operation down to 1.8 V, page-write timing (≤5 ms), block protection granularity (none/¼/½/all), and SOIC-8 (SN) package suitability for space-constrained PCB layouts.

Technical Context

The 25AA020A-I/SN implements a standard SPI Mode 0,0 or Mode 1,1 interface with separate SI (input) and SO (output) lines, requiring CS, SCK, SI, SO, WP, HOLD, VCC, and VSS. Its internal architecture includes an 8-bit instruction register, status register (WIP/WEL/BP0/BP1), and EEPROM array with page latches enabling up to 16-byte writes within aligned 16-byte boundaries.

Write operations require explicit WREN instruction followed by CS high-to-low transition to initiate self-timed internal write cycle (TWC ≤ 5 ms); read operations support sequential addressing with automatic address rollover at 0xFF. Built-in power-on write protection, hold-mode tri-state outputs, and ESD tolerance (>4 kV) ensure robustness in noisy industrial environments.

Key Specifications

Pinout & Package

25AA020A-I/SN is packaged in 8-lead SOIC (SN), with 1.27 mm pitch, body size 3.9 mm × 4.9 mm, and RoHS-compliant matte tin lead finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 25LC020A-I/SN and AT25020B-SSHL-T, the 25AA020A-I/SN uniquely supports 1.8 V operation while retaining hardware write-protection and industrial temperature range - making it optimal for ultra-low-power, mixed-voltage, and safety-critical embedded systems where voltage margin and physical lockout are mandatory.

Availability

25AA020A-I/SN is available at Aetrix Electronics and suitable for industrial sensor calibration, medical device configuration, smart energy meter firmware patch storage, and automotive body control module settings requiring stable component supply and long-term obsolescence management.

Supply support for 25AA020A-I/SN 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 devices, and memory solutions, headquartered in Chandler, Arizona, with global design, manufacturing, and sales operations.

The 25AA020A belongs to Microchip's serial EEPROM product line, designed specifically for reliable, low-power, SPI-based nonvolatile data storage in cost-sensitive and space-constrained embedded applications across industrial, medical, and automotive markets.

FAQ

What is the maximum clock frequency supported by the 25AA020A-I/SN?

The 25AA020A-I/SN supports a maximum clock frequency of 10 MHz when VCC is between 4.5 V and 5.5 V. At lower voltages (2.5–4.5 V), the limit drops to 5 MHz, and at 1.8–2.5 V, it is 3 MHz. These graded limits ensure reliable setup/hold timing across the full operating voltage range specified in the AC Characteristics table (DS21833G, Table 1-2).

Does the 25AA020A-I/SN support page writes, and what is the page size?

Yes, the 25AA020A-I/SN supports page writes with a fixed page size of 16 bytes. All bytes written in a single WRITE instruction must reside within the same physical page (addresses ending in 0000–1111 binary); attempting to cross a page boundary causes wraparound to the start of the current page rather than advancing to the next page.

How does the WP pin function on the 25AA020A-I/SN?

The WP (Write-Protect) pin on the 25AA020A-I/SN is a hardware-level disable for all write operations. When pulled low, it prevents writes to both memory array and STATUS register regardless of WEL bit state or WREN instruction. It does not affect read operations or HOLD functionality, and an ongoing write cycle will complete even if WP is asserted mid-cycle.

What is the endurance and data retention specification for the 25AA020A-I/SN?

The 25AA020A-I/SN is rated for 1,000,000 erase/write cycles and guarantees data retention exceeding 200 years at +25°C. These values are validated per Microchip's characterization methodology and reflect typical performance under recommended operating conditions - not accelerated test projections.

Is the 25AA020A-I/SN compatible with standard SPI Mode 0,0 and Mode 1,1?

Yes, the 25AA020A-I/SN is fully compatible with both SPI Mode 0,0 (CPOL = 0, CPHA = 0) and Mode 1,1 (CPOL = 1, CPHA = 1). Data is sampled on the rising edge of SCK for input (SI) and updated on the falling edge for output (SO), matching standard SPI timing conventions used by most microcontrollers including Microchip PIC® devices.