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Microchip Technology 25AA320AT-I/ST
- Part No.:
- 25AA320AT-I/ST
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
25AA320AT-I/ST.pdf
- Description:
- IC EEPROM 32KBIT SPI 8TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,870
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Product details
Overview
25AA320AT-I/ST from Microchip Technology Inc. is a 32-Kbit SPI Serial EEPROM with 4096 × 8-bit organization, 32-byte page size, and industrial temperature range (−40°C to +85°C). It operates from 1.8V–5.5V, supports up to 10 MHz clock frequency at 5.5V, and features hardware write protection via WP pin and STATUS register control. It is used in embedded systems for firmware parameter storage, calibration data retention, and configuration backup.
For engineers reviewing the 25AA320AT-I/ST datasheet, 25AA320AT-I/ST pinout, 25AA320AT-I/ST application, or 25AA320AT-I/ST equivalent, key selection criteria include SPI interface compatibility, 1.8V minimum VCC support, page-write timing (≤5 ms), HOLD functionality for interrupt-safe operation, and AEC-Q100 qualification for automotive-grade reliability.
Technical Context
The 25AA320AT-I/ST implements a standard SPI Mode 0,0/Master-Slave interface with separate SI (data-in) and SO (data-out) lines, CS-controlled selection, and SCK-synchronized transfers. Its internal architecture includes an 8-bit instruction register, page latches, and high-voltage generation circuitry for EEPROM programming.
It supports sequential read, byte/page write, and STATUS register access (RDSR/WRSR), with built-in power-on write-disable, WREN/WRDI latch control, and programmable block protection (BP0/BP1) enabling 0%, 25%, 50%, or 100% array write-protection. HOLD pin suspends ongoing SPI transactions without resetting address pointers.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 32 Kbit (4096 × 8-bit), sufficient for storing bootloader config, sensor calibration tables, or device identity data |
| Interface | SPI-compatible serial bus (Mode 0,0), requiring only CS, SCK, SI, SO - no I²C pull-up or arbitration logic needed |
| Max Clock Frequency | 10 MHz at VCC ≥ 4.5V; enables fast firmware updates (e.g., ~3.3 ms for full 4 KB read at 10 MHz) |
| Write Cycle Time | ≤5 ms self-timed internal write; eliminates need for external delay timers or polling overhead in host firmware |
| VCC Range | 1.8V–5.5V; supports direct interfacing with 1.8V logic microcontrollers and legacy 5V systems without level shifters |
| Data Retention | >200 years at +25°C; ensures long-term integrity of stored calibration or security keys across product lifecycle |
| Endurance | >1 million erase/write cycles; suitable for dynamic logging applications with frequent parameter updates |
Pinout & Package
25AA320AT-I/ST is packaged in an 8-lead TSSOP (Thin Shrink Small Outline Package) with 0.65 mm pitch, 3.0 mm × 4.4 mm body, and exposed pad optional grounding per Microchip Drawing C04-057-TS Rev G.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select Input | Active-low enable: pulls device out of standby; rising edge after valid write initiates internal 5 ms write cycle |
| SO | Serial Data Output | Tri-state open-drain output; data shifted out on SCK falling edge; high-impedance when CS high or HOLD low |
| WP | Write-Protect Pin | Hardware lock: disables STATUS register writes when WP = low and WPEN = 1; independent of WEL state |
| VSS | Ground Reference | Primary return path for all I/O and core logic; must be low-impedance to ensure noise immunity during SPI bursts |
| SI | Serial Data Input | CMOS input latching data on SCK rising edge; accepts 8-bit instructions (e.g., 0x03 for READ, 0x02 for WRITE) |
| SCK | Serial Clock Input | Asynchronous master clock; defines timing for SI sampling and SO update; max 10 MHz at 5.5V |
| HOLD | Hold Input | Pauses active SPI transfer: SO goes high-Z immediately; resumes from same bit position when HOLD returns high |
| VCC | Supply Voltage | 1.8V–5.5V core and I/O supply; decoupling capacitor (0.1 µF) required within 5 mm for stable 10 MHz operation |
Key Features
| Feature | Design Value |
|---|---|
| Page Write Capability | 32-byte page buffer allows burst writes within one physical page (0x000–0x01F, etc.), reducing SPI transaction count by up to 32× vs. byte writes |
| Block Write Protection | BP0/BP1 bits in STATUS register enable selective protection of 0%, 25%, 50%, or 100% of memory - prevents accidental overwrites of critical firmware sections |
| HOLD Functionality | Enables deterministic interruption of SPI sequences (e.g., during MCU ISR handling) without losing address pointer or reinitializing communication |
| Low-Voltage Operation | Full functionality down to 1.8V VCC permits direct integration with ultra-low-power MCUs (e.g., PIC16LF1xxx) without voltage translation |
| AEC-Q100 Qualification | Qualified to Grade 2 (−40°C to +105°C ambient) per Automotive Electronics Council standard - validated for under-hood and infotainment applications |
Applications
| Industrial Sensor Node | Automotive Body Control Module |
|---|---|
Use Scenario: Storing calibrated offset/gain coefficients and sensor linearization tables in wireless temperature/humidity nodes operating on coin-cell batteries. IC Role / Device Role / Timing Role: Nonvolatile configuration store accessed at boot and during field recalibration; HOLD pin used to pause reads during RF transmission interrupts. Use Value: 1.8V operation extends battery life; >200-year data retention ensures calibration validity over full product lifetime without periodic refresh. | Use Scenario: Retaining door lock actuator position limits, mirror fold/unfold presets, and seat memory profiles in 12V automotive ECUs. IC Role / Device Role / Timing Role: SPI-configurable EEPROM interfaced to 8-bit automotive MCU; WP pin hardwired to chassis ground for permanent protection of factory-set parameters. Use Value: AEC-Q100 qualification guarantees operation across thermal cycling and load-dump transients; 1M endurance supports daily user customization over 10+ years. |
| Medical Infusion Pump | Smart Energy Meter |
Use Scenario: Recording drug administration logs, dose history, and safety-critical alarm thresholds in Class II medical devices requiring traceable data integrity. IC Role / Device Role / Timing Role: Secure parameter vault with RDSR polling of WIP bit to prevent concurrent access during write cycles; STATUS register write-protected via WPEN + WP. Use Value: ESD rating >4 kV protects against handling damage during assembly; >200-year retention satisfies FDA 21 CFR Part 11 long-term audit requirements. | Use Scenario: Storing tariff schedules, metering constants, and tamper-event timestamps in ANSI C12.20-compliant electricity meters deployed for 20+ years. IC Role / Device Role / Timing Role: High-reliability data logger with page-write optimization to minimize flash wear; BP1/BP0 set to protect base metering constants from firmware updates. Use Value: 5 µA standby current at +85°C reduces system power budget; RoHS compliance meets global environmental regulations for utility infrastructure. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 25LC320AT-I/ST | Requires minimum 2.5V VCC; lacks 1.8V operation; otherwise identical pinout, timing, and feature set | Not suitable for 1.8V-only systems; acceptable where 3.3V or 5V rails dominate | Select only if system VCC ≥ 2.5V and cost sensitivity outweighs low-voltage flexibility |
| AT25DF321A-MAU-T | 32-Mbit density, quad SPI interface, 8-pin SOIC package; no HOLD pin; different command set and status register layout | Higher density but incompatible protocol; requires firmware rewrite and PCB layout change | Consider only for new designs needing >32 Kbit capacity and willing to adopt quad SPI architecture |
Compared with 25LC320AT-I/ST, the 25AA320AT-I/ST enables true 1.8V system integration and offers identical automotive qualification, while AT25DF321A-MAU-T provides greater density at the cost of interface compatibility and pin-level replaceability.
Availability
25AA320AT-I/ST is available at Aetrix Electronics and suitable for industrial sensor nodes, automotive body control modules, medical infusion pumps, and smart energy meters requiring stable component supply, long-term data integrity, and AEC-Q100-compliant nonvolatile storage.
Supply support for 25AA320AT-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, FPGA, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.
The 25AA320A family delivers SPI EEPROMs optimized for low-voltage embedded systems requiring robust data retention, automotive-grade reliability, and seamless integration with PIC® and dsPIC® microcontrollers.
FAQ
What is the maximum clock frequency supported by the 25AA320AT-I/ST?
The 25AA320AT-I/ST supports up to 10 MHz clock frequency when VCC is 4.5V–5.5V, 5 MHz at 2.5V–4.5V, and 3 MHz at 1.8V–2.5V. These AC characteristics are fully specified in Table 1-2 of DS20001828H and validated across the industrial temperature range. The 25AA320AT-I/ST uses these timing windows to guarantee reliable setup/hold margins for SI and SO transitions.
Does the 25AA320AT-I/ST support hardware write protection?
Yes, the 25AA320AT-I/ST supports dual-layer hardware write protection: (1) the WP pin disables STATUS register writes when WPEN = 1, and (2) BP0/BP1 bits configure 0%, 25%, 50%, or 100% array protection. This is implemented in silicon per DS20001828H Section 3.6 and Table 3-3, ensuring factory-set parameters remain immutable even during firmware updates.
What package type is used for the 25AA320AT-I/ST?
The 25AA320AT-I/ST uses an 8-lead TSSOP package (Microchip Drawing C04-057-TS Rev G), with 3.0 mm × 4.4 mm body, 0.65 mm lead pitch, and pin 1 marked by a dot or bevel. This matches the "ST" suffix in the part number and is confirmed in the Device Selection Table on DS20001828H-page 2.
How does the HOLD function operate on the 25AA320AT-I/ST?
The HOLD pin on the 25AA320AT-I/ST suspends active SPI communication without resetting the internal address pointer. When pulled low while SCK is low, SO immediately enters high-impedance state and SI/SCK transitions are ignored. Resuming requires HOLD high while SCK is low. This behavior is defined in Section 2.6 and Figure 1-1 of DS20001828H and enables deterministic interrupt handling in real-time systems using the 25AA320AT-I/ST.
Is the 25AA320AT-I/ST qualified for automotive applications?
Yes, the 25AA320AT-I/ST is AEC-Q100 qualified (Grade 2: −40°C to +105°C ambient) and RoHS compliant, as stated in the Features section of DS20001828H-page 1. This qualification covers stress testing for temperature cycling, humidity bias, and ESD, making the 25AA320AT-I/ST suitable for automotive body electronics, infotainment, and ADAS subsystems where data integrity under harsh conditions is mandatory.
25AA320AT-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:
- 10 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
25AA320AT-I/ST FAQ
1.How can I place an order for 25AA320AT-I/ST through Aetrix?
Please submit a Request for Quotation (RFQ) for 25AA320AT-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 25AA320AT-I/ST reliable?
The price and inventory of 25AA320AT-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 25AA320AT-I/ST is usually 5 days.
3.What payment methods are accepted for 25AA320AT-I/ST?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 25AA320AT-I/ST transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 25AA320AT-I/ST?
25AA320AT-I/ST orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 25AA320AT-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 25AA320AT-I/ST?
For technical support, including 25AA320AT-I/ST datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 25AA320AT-I/ST requirements.
6.How does Aetrix verify that 25AA320AT-I/ST is sourced from the original manufacturer or authorized distributors?
All 25AA320AT-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 25AA320AT-I/ST meets industry standards.
7.What is the process for return or replacement of 25AA320AT-I/ST?
All 25AA320AT-I/ST units undergo pre-shipment inspection (PSI). If there is an issue with 25AA320AT-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 25AA320AT-I/ST part is unused and in its original packaging.
Return procedure for 25AA320AT-I/ST:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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