Microchip Technology 25AA080A-I/ST

Overview

25AA080A-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, and 16-byte page write capability. It operates across -40°C to +85°C industrial temperature range in an 8-lead TSSOP package and supports up to 10 MHz clock frequency. This device serves as nonvolatile configuration storage in microcontroller-based embedded systems requiring low-power, high-reliability data retention.

For engineers reviewing the 25AA080A-I/ST datasheet, 25AA080A-I/ST pinout, 25AA080A-I/ST application, or 25AA080A-I/ST equivalent, key selection criteria include its 1.8 V minimum VCC operation, hardware write protection via WP pin and BP bits, HOLD functionality for interrupt-safe SPI pauses, and 1,000,000-cycle endurance for firmware parameter logging.

Technical Context

The 25AA080A-I/ST implements a standard SPI Mode 0,0 (CPOL=0, CPHA=0) interface with separate SI and SO lines, requiring CS, SCK, SI, SO, WP, HOLD, VCC, and VSS connections. Its internal architecture includes a write-enable latch, status register with WIP/WEL/BP0/BP1 bits, and page latches enabling atomic 16-byte writes within aligned memory boundaries.

Write operations require explicit WREN instruction followed by WRITE command and address; CS must go high after final data bit to trigger self-timed 5 ms internal write cycle. The HOLD pin suspends ongoing SPI transfers without resetting state, allowing host MCU to service higher-priority interrupts while preserving transaction context.

Key Specifications

Pinout & Package

25AA080A-I/ST is housed in an 8-lead TSSOP package (4.4 mm body width, 0.65 mm pitch), RoHS-compliant and Pb-free per JEDEC standards. Pin 1 is marked with a dot or beveled corner; leads are gull-wing profile with 0.19–0.30 mm width.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 25AA080A-I/ST, the 25LC080A-I/ST sacrifices 1.8 V operation for identical features at potentially lower cost, while the AT25080B-SSHL-T trades HOLD support and voltage flexibility for Atmel ecosystem compatibility - making 25AA080A-I/ST the optimal choice for new 1.8–5.5 V designs requiring robust interrupt handling.

Availability

25AA080A-I/ST is available at Aetrix Electronics and suitable for industrial sensor nodes, medical device calibration storage, automotive body control modules, and smart home gateways requiring stable component supply across extended product lifecycles.

Supply support for 25AA080A-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 microcontrollers, analog components, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 25AA080A-I/ST belongs to Microchip's 25XX080A/B family of SPI Serial EEPROMs, designed specifically for reliable, low-power nonvolatile data storage in resource-constrained embedded systems where voltage flexibility and interrupt-safe communication are critical.

FAQ

What is the minimum supply voltage required for reliable operation of the 25AA080A-I/ST?

The 25AA080A-I/ST supports operation down to 1.8 V across its full industrial temperature range (-40°C to +85°C). Below this threshold, read/write functionality is not guaranteed per datasheet specifications. This 1.8 V minimum enables direct use with modern ultra-low-power MCUs and battery-backed systems without external level-shifting circuitry. Always verify actual VCC stability under load using a 0.1 µF ceramic bypass capacitor placed adjacent to the VCC pin of the 25AA080A-I/ST.

How does the HOLD pin function during an active SPI transaction with the 25AA080A-I/ST?

The HOLD pin on the 25AA080A-I/ST suspends ongoing SPI communication without resetting internal state: when pulled low while SCK is low, SI/SO/SCK inputs are ignored and SO enters high-impedance, preserving the current address pointer and command context. To resume, HOLD must be raised while SCK remains low. This allows the host MCU to service urgent interrupts and return seamlessly to the same transaction - a critical capability for real-time systems where retransmission overhead is unacceptable. The 25AA080A-I/ST must remain selected (CS low) throughout the HOLD period.

Can the 25AA080A-I/ST be used for secure storage of cryptographic keys?

The 25AA080A-I/ST provides hardware-assisted write protection via the WP pin and BP0/BP1 bits in its status register, enabling selective locking of memory blocks - including full-array protection. However, it offers no encryption, tamper detection, or secure boot features. Keys stored in 25AA080A-I/ST are accessible via standard SPI reads and thus vulnerable to physical probing or bus snooping. For true cryptographic key storage, dedicated secure EEPROMs or secure elements with hardware encryption engines should be used instead of relying solely on the 25AA080A-I/ST's write-protection mechanisms.

What happens if a page write command crosses a 16-byte boundary on the 25AA080A-I/ST?

If a page write command attempts to cross a 16-byte boundary on the 25AA080A-I/ST, data wraps around to the start of the current page instead of advancing to the next page - overwriting previously written bytes in that same page. This behavior is defined by the device's internal page latch architecture and is not an error condition. Application firmware must explicitly check address alignment and split multi-page writes across sequential commands. Failure to do so results in unintended data corruption, which cannot be recovered without external verification logic or redundant storage schemes.

Is the 25AA080A-I/ST pin-compatible with other members of the 25XX080A/B family?

Yes, the 25AA080A-I/ST is fully pin-compatible with all 25XX080A/B variants (including 25AA080B-I/ST, 25LC080A-I/ST, and 25LC080B-I/ST) in the same package type (e.g., TSSOP-ST). All share identical 8-pin TSSOP footprints, pin functions, and SPI protocol timing. However, differences exist in VCC range (1.8–5.5 V vs. 2.5–5.5 V), page size (16 vs. 32 bytes), and temperature grade - so electrical and functional compatibility must be verified against the target application's voltage and timing requirements before substitution.