Microchip Technology 25AA080B-I/ST

Overview

25AA080B-I/ST from Microchip Technology Inc. is an 8 Kbit SPI Serial EEPROM with 1024 × 8-bit organization, 32-byte page size, 1.8–5.5 V supply range, and industrial temperature rating (−40°C to +85°C). It features hardware write protection via WP pin, HOLD functionality for interrupt-safe bus suspension, and self-timed 5 ms max write cycles - deployed in embedded control systems for parameter storage and firmware configuration.

For engineers reviewing the 25AA080B-I/ST datasheet, 25AA080B-I/ST pinout, 25AA080B-I/ST application, or 25AA080B-I/ST equivalent, key selection criteria include SPI interface compatibility, 32-byte page write capability, 1.8 V minimum VCC operation, industrial-temperature reliability, and hardware-based block protection (BP0/BP1) for secure configuration data retention.

Technical Context

The 25AA080B-I/ST implements a standard SPI Mode 0,0/Master-Slave interface with separate SI (data in), SO (data out), SCK (clock), CS (chip select), WP (write-protect), and HOLD (bus pause) signals. Its internal architecture includes an 8-bit instruction register, status register with WIP/WEL/BP0/BP1 bits, and page latches enabling burst writes within 32-byte boundaries.

Write operations require explicit WREN instruction before WRITE, followed by CS high to trigger self-timed 5 ms internal erase/write cycle. During active write, memory reads return undefined data while RDSR remains accessible to monitor WIP bit - ensuring deterministic timing control in real-time microcontroller applications.

Key Specifications

Pinout & Package

25AA080B-I/ST is housed in an 8-lead TSSOP package (4.4 mm body width, 0.65 mm pitch), optimized for high-density PCB layouts and automated assembly. Pin 1 is marked by a beveled corner or dot; leads are Pb-free and RoHS compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 25AA080A-I/ST, the 25AA080B-I/ST delivers 2× page write throughput and identical low-voltage support; versus AT25080B-SSHL-T, it enables 1.8 V operation and maintains Microchip's BP0/BP1 protection model - critical for safety-certified medical or industrial deployments.

Availability

25AA080B-I/ST is available at Aetrix Electronics and suitable for motor control systems, smart sensor nodes, IoT edge devices, and medical diagnostic equipment requiring stable component supply across extended production lifecycles.

Supply support for 25AA080B-I/ST 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, analog, and Flash-IP solutions, serving automotive, industrial, consumer, and communications markets with integrated silicon and development tools.

The 25AA080B-I/ST belongs to Microchip's serial EEPROM product line, engineered for reliable, low-power nonvolatile storage in resource-constrained embedded systems where SPI interface simplicity and industrial-grade endurance are essential.

FAQ

What is the maximum SPI clock frequency supported by the 25AA080B-I/ST?

The 25AA080B-I/ST supports up to 10 MHz SPI clock frequency when VCC is 4.5–5.5 V, 5 MHz at 2.5–4.5 V, and 3 MHz at 1.8–2.5 V. These graded limits ensure timing margin compliance across its full 1.8–5.5 V operating range, as specified in Table 1-2 of DS21808D. The 25AA080B-I/ST must be configured accordingly in the host MCU's SPI peripheral to avoid setup/hold violations.

How does the 25AA080B-I/ST handle page boundary crossings during write operations?

The 25AA080B-I/ST restricts page writes to within a single 32-byte physical page - addresses 0x000–0x01F, 0x020–0x03F, etc. If a page write command crosses a boundary (e.g., starting at 0x01E with 4 bytes), data wraps to the start of the same page (0x01E, 0x01F, 0x000, 0x001), overwriting prior content. This behavior is documented in DS21808D Section 2.3 and applies identically to the 25AA080B-I/ST.

Can the 25AA080B-I/ST be used in 1.8 V systems without level shifters?

Yes, the 25AA080B-I/ST is fully specified for 1.8–5.5 V operation, including all DC and AC characteristics (e.g., VIH1/VIL1 thresholds, FCLK limits, ICC values). Its inputs are 5 V tolerant when VCC = 1.8 V, and SO output drives valid logic levels compatible with 1.8 V receivers. No level shifting is needed when interfacing with 1.8 V MCUs - a key differentiator from the 25LC080B variant.

What protection mechanisms prevent accidental writes to the 25AA080B-I/ST?

The 25AA080B-I/ST employs three layered protections: (1) a volatile write-enable latch (WEL) reset on power-up and after each write, requiring explicit WREN instruction; (2) nonvolatile BP0/BP1 bits enabling hardware block protection of 0%, 25%, 50%, or 100% of memory; and (3) WP pin + WPEN bit enabling physical write-disable of status register. All are active in the 25AA080B-I/ST per DS21808D Sections 2.4–2.6.

Is the HOLD function of the 25AA080B-I/ST compatible with standard SPI bus sharing?

Yes, the HOLD pin suspends ongoing SPI transactions without releasing the bus or resetting internal state - allowing the host MCU to service urgent interrupts and resume transmission seamlessly. While HOLD is asserted, SI/SO/SCK are tri-stated and ignored except CS, preserving multi-peripheral SPI bus integrity. This behavior is electrically verified for the 25AA080B-I/ST in DS21808D Figure 1-1 and Section 3.6.