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Home > Products > Integrated Circuits (ICs) > Memory > Memory

Microchip Technology 25AA320XT-I/ST

Name: 25AA320XT-I/ST
Brand: Microchip Technology
SKU: 25AA320XT-I/ST
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 25AA320XT-I/ST

Manufacturer:: Microchip Technology

Category:: Memory

Package:: 8-TSSOP (0.173", 4.40mm Width)

Datasheet:: 25AA320XT-I/ST.pdf

Description:: IC EEPROM 32KBIT SPI 1MHZ 8TSSOP

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Product details

Overview

25AA320XT-I/ST from Microchip Technology Inc. is a 32 Kbit (4096 × 8) SPI serial EEPROM with 1.8–5.5 V supply, 1 MHz max clock, and industrial temperature range (−40°C to +85°C). It features 32-byte page write, 5 ms max internal write cycle time, hardware write protection via WP pin and STATUS register, and operates in 8-lead TSSOP package. It serves as nonvolatile configuration storage in microcontroller-based embedded systems requiring low-power, reliable data retention.

For engineers reviewing the 25AA320XT-I/ST datasheet, 25AA320XT-I/ST pinout, 25AA320XT-I/ST application, or 25AA320XT-I/ST equivalent, key selection criteria include V_CC compatibility (1.8–5.5 V), SPI timing compliance (T_CSS/T_CSH ≤ 500 ns at 1.8 V), page-write boundary handling, HOLD functionality for interrupt-safe bus arbitration, and hardware block protection granularity (none/¼/½/all array).

Technical Context

The 25AA320XT-I/ST implements a standard SPI Mode 0,0 interface (CPOL = 0, CPHA = 0) with separate SI/SO lines, CS-controlled device selection, and HOLD-driven pause/resume capability. Its internal architecture includes an 8-bit instruction register, auto-incrementing address pointer for sequential reads, and a STATUS register with WIP, WEL, BP1/BP0, and WPEN bits controlling write enable state and 4-level block protection.

Write operations require explicit WREN instruction followed by WRITE command and address/data; CS must be raised after final data bit to initiate self-timed 5 ms internal write cycle. During writes, SO enters high-impedance, memory reads are blocked, but RDSR remains accessible to poll WIP status - enabling deterministic firmware wait-loop implementation without bus contention.

Key Specifications

Parameter	Value and Actual Design Meaning
Memory size	32 Kbit (4096 × 8 bits); supports up to 32-byte page writes within same 32-byte-aligned boundary
V_CC range	1.8 V to 5.5 V; enables direct interfacing with 1.8 V, 3.3 V, and 5 V microcontrollers without level shifting
Max clock frequency	1 MHz at V_CC ≥ 1.8 V; defines maximum SPI transaction throughput (e.g., ~32 kbps byte read)
Write cycle time	5 ms maximum; determines minimum interval between consecutive page writes or STATUS register updates
Endurance & retention	1 million erase/write cycles; >200 years data retention - validated for long-life industrial logging and calibration storage
Standby current	500 nA typical at V_CC = 2.5 V; critical for battery-powered devices requiring ultra-low quiescent power
ESD rating	>4000 V HBM; ensures robustness against handling and board-level electrostatic discharge events

Pinout & Package

25AA320XT-I/ST is housed in an 8-lead plastic TSSOP (4.4 mm body width) package per Microchip's ordering code "ST", with lead pitch of 0.65 mm and JEDEC MO-153 compliant footprint. Pin 1 is marked with a dot or notch; pin numbering follows standard counter-clockwise orientation when viewed top-down with marking side up.

Pin/Terminal	Circuit Role	Design Meaning
1 (HOLD)	Hold input	Pauses ongoing SPI transfer without resetting sequence; must be held high when unused; tri-states SO when asserted
2 (V_CC)	Supply voltage	1.8–5.5 V logic and memory core supply; decoupling capacitor (0.1 µF) required near pin
3 (CS)	Chip select	Active-low enable; deselects device and forces SO into high-impedance; initiates write cycle on rising edge after valid write sequence
4 (SO)	Serial output	Data-out line; outputs memory contents on falling SCK edge; high-impedance when CS high or HOLD active
5 (WP)	Write-protect	Hardware lock for STATUS register nonvolatile bits when WPEN = 1; grounded to disable STATUS writes; no effect if WPEN = 0
6 (V_SS)	Ground	Reference return path for all I/O and core circuitry; must be low-impedance connection to system ground plane
7 (SI)	Serial input	Data-in line; latches instructions, addresses, and data on rising SCK edge; MSB-first protocol
8 (SCK)	Serial clock	Synchronizes all SPI transfers; rising edge clocks data in (SI), falling edge clocks data out (SO)

Key Features

Feature	Design Value
Low-voltage operation	1.8 V minimum V_CC enables compatibility with modern ultra-low-power MCUs and energy-harvesting systems
Page write buffer	32-byte internal buffer allows burst programming of aligned pages - reducing total write cycles vs. byte-by-byte writes
HOLD functionality	Enables host MCU to service higher-priority interrupts mid-transfer without losing SPI context or re-synchronizing
Hardware block protection	BP1/BP0 bits + WP pin support four protection levels (none, upper 1/4, upper 1/2, full array) - preventing accidental firmware corruption
Power-on safety	Write enable latch resets at power-up; SO defaults to high-Z; eliminates spurious writes during brown-out or reset sequences

Applications

Industrial Sensor Calibration	Medical Device Configuration
Use Scenario: Storing calibrated offset/gain coefficients for analog sensor front-ends in programmable logic controllers. IC Role / Device Role / Timing Role: Nonvolatile configuration storage accessed during boot and field recalibration; SPI interface synchronized to MCU clock domain. Use Value: 1M endurance supports frequent recalibration; 200-year retention ensures lifetime accuracy without battery backup; 1.8 V operation matches low-power sensor SoCs.	Use Scenario: Holding patient-specific therapy parameters and device serialization data in portable infusion pumps. IC Role / Device Role / Timing Role: Secure, tamper-resistant parameter store; WP pin tied low with WPEN set to prevent runtime corruption of critical settings. Use Value: Hardware write protection prevents unauthorized modification; 4000 V ESD rating withstands clinical environment handling; industrial temp range covers operating envelope.
Automotive Body Control Module	Smart Energy Meter Firmware
Use Scenario: Saving seat/mirror position presets and lighting profiles in vehicle BCMs across ignition cycles. IC Role / Device Role / Timing Role: Persistent user preference storage; accessed via SPI during initialization; HOLD used to defer writes during CAN bus interrupt servicing. Use Value: 5 ms write time fits within BCM boot timing budget; 500 nA standby current minimizes parasitic drain on 12 V battery; −40°C to +85°C rating meets automotive under-hood requirements.	Use Scenario: Storing tariff tables, meter calibration constants, and firmware update staging data in ANSI C12.22-compliant smart meters. IC Role / Device Role / Timing Role: Secure, field-updatable configuration repository; STATUS register monitored during OTA updates to verify write completion before committing. Use Value: RDSR polling enables deterministic firmware control over write progress; block protection isolates tariff tables from application code updates; 32-byte page aligns with meter firmware sector boundaries.

Industrial Sensor Calibration

Medical Device Configuration

Use Scenario: Storing calibrated offset/gain coefficients for analog sensor front-ends in programmable logic controllers.

IC Role / Device Role / Timing Role: Nonvolatile configuration storage accessed during boot and field recalibration; SPI interface synchronized to MCU clock domain.

Use Value: 1M endurance supports frequent recalibration; 200-year retention ensures lifetime accuracy without battery backup; 1.8 V operation matches low-power sensor SoCs.

Use Scenario: Holding patient-specific therapy parameters and device serialization data in portable infusion pumps.

IC Role / Device Role / Timing Role: Secure, tamper-resistant parameter store; WP pin tied low with WPEN set to prevent runtime corruption of critical settings.

Use Value: Hardware write protection prevents unauthorized modification; 4000 V ESD rating withstands clinical environment handling; industrial temp range covers operating envelope.

Automotive Body Control Module

Smart Energy Meter Firmware

Use Scenario: Saving seat/mirror position presets and lighting profiles in vehicle BCMs across ignition cycles.

IC Role / Device Role / Timing Role: Persistent user preference storage; accessed via SPI during initialization; HOLD used to defer writes during CAN bus interrupt servicing.

Use Value: 5 ms write time fits within BCM boot timing budget; 500 nA standby current minimizes parasitic drain on 12 V battery; −40°C to +85°C rating meets automotive under-hood requirements.

Use Scenario: Storing tariff tables, meter calibration constants, and firmware update staging data in ANSI C12.22-compliant smart meters.

IC Role / Device Role / Timing Role: Secure, field-updatable configuration repository; STATUS register monitored during OTA updates to verify write completion before committing.

Use Value: RDSR polling enables deterministic firmware control over write progress; block protection isolates tariff tables from application code updates; 32-byte page aligns with meter firmware sector boundaries.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
25AA320A-I/ST	Revised version with enhanced reliability; identical pinout, timing, and electrical specs; recommended for new designs per Microchip DS21227F rev F	No functional change; drop-in replacement with improved manufacturing process and extended lifecycle support	Select 25AA320A-I/ST for new designs to ensure long-term availability and latest qualification standards
AT25DF321A-SSHN-B	32 Mbit SPI DataFlash with sector erase; 2.7–3.6 V only; no HOLD pin; different instruction set and status register layout	Higher density suited for firmware storage; lacks HOLD and hardware write protection granularity; requires driver rewrite	Choose only if >32 Kbit capacity is needed and system can accommodate voltage and protocol differences

Compared with 25AA320XT-I/ST, the 25AA320A-I/ST offers identical functionality with updated process reliability, while AT25DF321A-SSHN-B provides greater density at the cost of voltage flexibility, HOLD support, and protection configurability - making it unsuitable as a direct substitute.

Availability

25AA320XT-I/ST is available at Aetrix Electronics and suitable for industrial sensor calibration, medical device configuration, automotive body control modules, and smart energy meter firmware requiring stable component supply and long-term obsolescence management.

Supply support for 25AA320XT-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, mixed-signal, analog, and Flash-IP solutions, headquartered in Chandler, Arizona, with global design, manufacturing, and sales operations.

The 25AA320XT-I/ST belongs to Microchip's legacy 25XX320 SPI EEPROM family, designed specifically for low-voltage, low-power embedded systems needing reliable, pin-efficient nonvolatile storage with hardware-based data integrity safeguards.

FAQ

What is the maximum clock frequency supported by the 25AA320XT-I/ST?

The 25AA320XT-I/ST supports a maximum SPI clock frequency of 1 MHz across its full 1.8–5.5 V V_CC range. This limit is specified in the Device Selection Table and confirmed in Table 1-2 AC Characteristics (Param No. 1, FCLK). At lower V_CC (e.g., 1.8 V), timing margins tighten - e.g., T_CSS increases to 500 ns - but the 1 MHz rate remains valid. Exceeding this frequency risks setup/hold violations and unreliable communication.

Does the 25AA320XT-I/ST support hardware write protection, and how is it configured?

Yes, the 25AA320XT-I/ST supports hardware write protection via the WP pin and STATUS register's WPEN bit. When WPEN = 1 and WP is driven low, writes to nonvolatile STATUS bits (BP0, BP1, WPEN) are disabled. Block protection for memory is controlled by BP0/BP1 bits, offering four levels: none, upper 1/4, upper 1/2, or full array. WP must be externally pulled low and WPEN set via WRSR instruction to activate hardware lock.

What is the purpose of the HOLD pin on the 25AA320XT-I/ST, and how must it be used?

The HOLD pin on the 25AA320XT-I/ST pauses ongoing SPI communication without resetting the sequence. To invoke HOLD, the pin must be pulled low while SCK is low; doing so tri-states SO, SI, and SCK inputs are ignored (except CS). To resume, HOLD must be raised while SCK is low. Misuse - such as toggling HOLD during SCK high - delays resumption until the next SCK high-to-low transition, risking timing errors in time-critical systems.

How many erase/write cycles does the 25AA320XT-I/ST guarantee, and what is its data retention period?

The 25AA320XT-I/ST guarantees 1 million erase/write cycles per memory location and greater than 200 years of data retention at +25°C ambient, as stated in the Features section and Table 1-1 Note 2. These values are established by characterization (not 100% tested) and reflect typical performance under specified operating conditions. Endurance may vary with temperature and V_CC; Microchip's Total Endurance™ Model provides application-specific estimates.

Is the 25AA320XT-I/ST pin-compatible with other members of the 25XX320 family, such as the 25LC320XT-I/ST?

Yes, the 25AA320XT-I/ST shares identical 8-lead TSSOP pinout and function mapping with 25LC320XT-I/ST and 25C320XT-I/ST, as confirmed in Table 2-1 Pin Function Table and Package Types diagram. However, they differ in V_CC range (1.8–5.5 V vs. 2.5–5.5 V vs. 4.5–5.5 V) and max clock frequency (1 MHz vs. 2 MHz vs. 3 MHz). Electrical substitution is possible only if the host system's supply and timing meet the target device's specifications.

25AA320XT-I/ST Specifications

Product attributes: Attribute value

Manufacturer:: Microchip Technology

Series:: -

Package/Case:: 8-TSSOP (0.173", 4.40mm Width)

Packaging:: Tape & Reel (TR)

Product Status:: Active

Programmable:: Verified

Memory Type:: Non-Volatile

Memory Format:: EEPROM

Technology:: EEPROM

Memory Size:: 32Kbit

Memory Organization:: 4K x 8

Memory Interface:: SPI

Clock Frequency:: 1 MHz

Write Cycle Time - Word, Page:: 5ms

Access Time:: -

Voltage - Supply:: 1.8V ~ 5.5V

Operating Temperature:: -40°C ~ 85°C (TA)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 8-TSSOP

25AA320XT-I/ST FAQ

1.How can I place an order for 25AA320XT-I/ST through Aetrix?

Please submit a Request for Quotation (RFQ) for 25AA320XT-I/ST on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for 25AA320XT-I/ST reliable?

The price and inventory of 25AA320XT-I/ST are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 25AA320XT-I/ST is usually 5 days.

3.What payment methods are accepted for 25AA320XT-I/ST?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 25AA320XT-I/ST transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 25AA320XT-I/ST?

25AA320XT-I/ST orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 25AA320XT-I/ST order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for 25AA320XT-I/ST?

For technical support, including 25AA320XT-I/ST datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 25AA320XT-I/ST requirements.

6.How does Aetrix verify that 25AA320XT-I/ST is sourced from the original manufacturer or authorized distributors?

All 25AA320XT-I/ST products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that 25AA320XT-I/ST meets industry standards.

7.What is the process for return or replacement of 25AA320XT-I/ST?

All 25AA320XT-I/ST units undergo pre-shipment inspection (PSI). If there is an issue with 25AA320XT-I/ST, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The 25AA320XT-I/ST part is unused and in its original packaging.

Return procedure for 25AA320XT-I/ST:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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