Microchip Technology 25AA1024-I/WF16K

Overview

25AA1024-I/WF16K from Microchip Technology is a 1-Mbit (131,072-byte) SPI serial EEPROM with byte/page write, 256-byte page size, 6 ms max internal write cycle time, and industrial temperature range (–40°C to +85°C). It operates from 1.8V–5.5V, supports up to 20 MHz clock at 4.5–5.5V, and features hardware write protection via WP pin and STATUS register control - used in embedded systems for firmware parameter storage, calibration data retention, and configuration backup.

For engineers reviewing the 25AA1024-I/WF16K datasheet, 25AA1024-I/WF16K pinout, 25AA1024-I/WF16K application, or 25AA1024-I/WF16K equivalent, key selection criteria include SPI timing compliance at 2.0V–5.5V supply, deep power-down current (1 µA at 2.5V/85°C), sector-level write protection granularity (32 KB per sector), and AEC-Q100 qualification for automotive subsystems.

Technical Context

The 25AA1024-I/WF16K implements a standard SPI Mode 0,0/Master-Slave interface with separate SI (data-in) and SO (data-out) lines, requiring CS, SCK, HOLD, and WP control signals. Its memory array is organized into 512 pages of 256 bytes each, supporting byte, page, sector (32 KB), and full-chip erase operations - all self-timed and non-blocking to host firmware.

It integrates dual-layer write protection: volatile WEL latch (set/reset via WREN/WRDI) and nonvolatile BP0/BP1 bits (programmed via WRSR) enabling selective 0%, 25%, 50%, or 100% array lock. The HOLD pin suspends ongoing SPI transfers without resetting state, allowing interrupt servicing while preserving command context.

Key Specifications

Pinout & Package

25AA1024-I/WF16K uses an 8-lead DFN package (3 mm × 2 mm, 0.5 mm pitch) with exposed thermal pad (optional VSS connection). Pin functions are electrically identical across DFN, PDIP, and SOIJ variants.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 25AA1024-I/WF16K, AT25DF041A offers higher speed and density but removes HOLD and deep power-down - reducing suitability for interrupt-driven or battery-powered systems. BR24G1M adds ECC for fault tolerance but increases standby current and eliminates sector-level erase flexibility.

Availability

25AA1024-I/WF16K is available at Aetrix Electronics and suitable for industrial PLCs, automotive ECUs, medical infusion pumps, smart utility meters, and battery-powered IoT edge nodes requiring stable component supply across extended product lifecycles.

Supply support for 25AA1024-I/WF16K 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 microcontroller, mixed-signal, analog, and Flash-IP solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 25AA1024 belongs to Microchip's industrial-grade serial EEPROM product line, designed specifically for reliable, low-power, SPI-based nonvolatile storage in harsh environments - emphasizing AEC-Q100 qualification, extended temperature operation, and robust write-protection architecture.

FAQ

What is the supply voltage range supported by the 25AA1024-I/WF16K?

The 25AA1024-I/WF16K operates from 1.8V to 5.5V, with guaranteed AC performance down to 2.0V at the industrial temperature range (–40°C to +85°C). At 1.8V, it supports 2 MHz clock frequency and maintains full DC functionality including deep power-down mode (1 µA at 2.5V/85°C). This wide range enables direct interfacing with 1.8V, 3.3V, and 5V microcontrollers without level-shifting circuitry.

Does the 25AA1024-I/WF16K support true SPI Mode 0,0 operation?

Yes, the 25AA1024-I/WF16K implements standard SPI Mode 0,0 (CPOL = 0, CPHA = 0): data is sampled on the rising edge of SCK and shifted out on the falling edge. Its SI and SO lines are unidirectional, eliminating contention issues found in 3-wire variants. Timing parameters like TSU (data setup) and THD (data hold) are fully specified across VCC ranges, ensuring interoperability with PIC, ARM Cortex-M, and other SPI masters.

How does the HOLD function behave during an active write cycle in the 25AA1024-I/WF16K?

The HOLD pin cannot suspend an internal write cycle once initiated - the 25AA1024-I/WF16K completes all self-timed erase/write operations regardless of HOLD state. However, HOLD can pause ongoing SPI command sequences (e.g., multi-byte reads or address setup) before CS is raised. When HOLD goes low during such a sequence, SO immediately enters high-impedance, and the device retains its internal state until HOLD is returned high while SCK is low.

Can the 25AA1024-I/WF16K be used in automotive applications requiring AEC-Q100 compliance?

Yes, the 25AA1024-I/WF16K is explicitly AEC-Q100 qualified (Grade 3: –40°C to +85°C) and listed in Microchip's official automotive product portfolio. Its qualification includes stress testing for temperature cycling, humidity bias, and mechanical shock - making it suitable for body control modules, infotainment systems, and ADAS sensors where extended reliability and traceable manufacturing are mandated.

What happens if a page write crosses a 256-byte boundary in the 25AA1024-I/WF16K?

If a page write command attempts to cross a 256-byte physical page boundary, data wraps around to the start of the same page instead of advancing to the next page - overwriting previously loaded bytes within that page. This behavior is documented in the datasheet and requires firmware to enforce page-aligned addressing. The 25AA1024-I/WF16K does not auto-segment or reject misaligned writes; correct boundary handling is the host system's responsibility.