Microchip Technology 25AA080AT-I/ST

Overview

25AA080AT-I/ST from Microchip Technology Inc. is an 8 Kbit SPI Serial EEPROM with 1024 × 8-bit organization, 1.8–5.5 V supply range, 16-byte page size, and industrial temperature rating (–40°C to +85°C). It features hardware write protection via WP pin, HOLD suspend functionality, and self-timed 5 ms max write cycles - deployed in embedded control systems for firmware parameter storage and calibration data retention.

For engineers reviewing the 25AA080AT-I/ST datasheet, 25AA080AT-I/ST pinout, 25AA080AT-I/ST application, or 25AA080AT-I/ST equivalent, key selection criteria include VCC min (1.8 V), page size (16 bytes), HOLD/CS timing margins, and WPEN-controlled hardware write protection compatibility with host SPI controllers.

Technical Context

The 25AA080AT-I/ST implements a standard SPI Mode 0,0/M1,1 interface with separate SI/SO lines and active-low CS. Its internal architecture includes a write-enable latch, status register with WIP/WEL/BP bits, and page latches enabling burst writes within 16-byte boundaries without crossing physical page limits.

Write operations require explicit WREN instruction followed by CS high-to-low transition to initiate internal 5 ms erase/write cycle; during this time, RDSR remains readable while array reads return undefined data. HOLD pin suspends ongoing SPI transfers with guaranteed recovery on SCK low-to-high edge.

Key Specifications

Pinout & Package

25AA080AT-I/ST is housed in an 8-lead TSSOP package (4.4 mm body width, 0.65 mm pitch), optimized for space-constrained PCB layouts while maintaining hand-solderability and thermal performance in industrial environments.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 25LC080AT-I/ST and AT25080B-SSHL-T, the 25AA080AT-I/ST uniquely supports 1.8 V operation while retaining HOLD functionality and Microchip's proven block protection scheme - making it optimal for mixed-voltage embedded systems requiring robust interrupt-aware EEPROM access.

Availability

25AA080AT-I/ST is available at Aetrix Electronics and suitable for industrial PLCs, medical infusion pumps, automotive body control modules, and smart energy meters requiring stable component supply across extended temperature ranges and multi-decade lifecycles.

Supply support for 25AA080AT-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, headquartered in Chandler, Arizona, with global design and manufacturing infrastructure.

The 25AA080A/B family was designed specifically for reliable, low-voltage serial data storage in resource-constrained embedded systems - emphasizing write-protection flexibility, SPI interoperability, and extended data retention under industrial thermal stress.

FAQ

What is the minimum supply voltage required for reliable operation of the 25AA080AT-I/ST?

The 25AA080AT-I/ST operates reliably from 1.8 V to 5.5 V. At 1.8 V, maximum clock frequency is 3 MHz and timing margins (e.g., TCSS, THD) expand to 150 ns; full 10 MHz operation requires VCC ≥ 4.5 V. This wide range allows direct integration with both ultra-low-power MCUs and legacy 5 V systems without level shifters - a key advantage over 25LC080A variants that require ≥2.5 V.

How does the HOLD pin function during an active SPI transaction on the 25AA080AT-I/ST?

The HOLD pin on the 25AA080AT-I/ST suspends ongoing SPI communication without resetting internal state. To activate HOLD, the pin must be pulled low while SCK is low; SO enters high-impedance, and SI/SCK inputs are ignored until HOLD returns high (also while SCK is low). This enables host processors to service time-critical interrupts - such as motor control events - then resume exactly where the transaction left off, preserving byte alignment and addressing context within the 25AA080AT-I/ST.

Can the 25AA080AT-I/ST perform page writes across memory boundaries?

No. The 25AA080AT-I/ST enforces strict 16-byte page boundaries: any page write attempting to cross from address 0x000F to 0x0010 wraps data back to address 0x0000 instead of advancing to the next page. This behavior is defined by the physical page latch architecture and requires firmware to validate address alignment before issuing WRITE commands. Unlike devices with larger page buffers, the 25AA080AT-I/ST mandates explicit page management - a constraint confirmed in DS21808D Section 2.3 and Figure 2-3.

What protection mechanisms prevent unintended writes to the 25AA080AT-I/ST during power-up or brown-out conditions?

The 25AA080AT-I/ST incorporates three layered protections: (1) the write-enable latch (WEL) resets automatically at power-on, blocking all writes until WREN is issued; (2) WRDI and successful WRITE/WRSR operations also clear WEL; and (3) built-in power-on/off data protection circuitry holds internal logic in reset until VCC stabilizes within specification. These features ensure that transient supply conditions cannot corrupt stored data - a requirement verified in DS21808D Sections 2.4 and 2.7.

Is the 25AA080AT-I/ST pin-compatible with other members of the 25XX080A/B family?

Yes - the 25AA080AT-I/ST shares identical 8-lead TSSOP (ST) pinout, electrical characteristics, and instruction set with 25LC080AT-I/ST, 25AA080A-I/P, and 25LC080A-I/SN. All variants use the same CS/SO/WP/VSS/SI/SCK/HOLD/VCC arrangement and support READ/WRITE/RDSR/WRSR opcodes. However, voltage range (1.8–5.5 V vs. 2.5–5.5 V) and page size (16 vs. 32 bytes in 'B' versions) differ, so functional substitution requires validation of those parameters in the target application.