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Microchip Technology 25LC320AXT-E/ST
- Part No.:
- 25LC320AXT-E/ST
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
25LC320AXT-E/ST.pdf
- Description:
- IC EEPROM 32KBIT SPI 8TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,956
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Product details
Overview
25LC320AXT-E/ST from Microchip Technology Inc. is a 32-Kbit SPI Serial EEPROM with 4096 × 8-bit organization, 32-byte page size, and AEC-Q100 qualified Extended temperature operation (–40°C to +125°C). It supports up to 10 MHz clock frequency at 4.5–5.5 V, features hardware write protection via WP pin and STATUS register, and delivers >1 million erase/write cycles with >200-year data retention - deployed in automotive body control modules for configuration storage.
For engineers reviewing the 25LC320AXT-E/ST datasheet, 25LC320AXT-E/ST pinout, 25LC320AXT-E/ST application, or 25LC320AXT-E/ST equivalent, key selection criteria include its 8-lead TSSOP package, 2.5–5.5 V supply range, HOLD/CS/SO/SI/SCK/WP/VSS/VCC pin interface, block-level write protection (0%, 25%, 50%, or 100% array), and self-timed 5 ms max internal write cycle.
Technical Context
The 25LC320AXT-E/ST implements a standard SPI Mode 0,0/Master-Slave interface with separate SI (data-in) and SO (data-out) lines, requiring CS assertion and SCK synchronization. Its internal architecture includes an 8-bit instruction register, page latches, HV generator, and EEPROM array with X/Y decoders and sense amplifiers - enabling byte- and page-write operations within strict 32-byte physical page boundaries.
Write enable logic relies on a volatile WEL bit set by WREN and cleared by WRDI, power-up, or successful WRITE/WRSR execution. Hardware write protection is conditional: active only when WPEN=1 in STATUS register *and* WP pin is low; otherwise, all nonvolatile bits remain writable. HOLD functionality suspends ongoing serial transfers without resetting state, tri-stating SO on HOLD low and resuming on HOLD high while SCK is low.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 32 Kbit (4096 × 8-bit), directly addressable via 16-bit SPI command addressing |
| Interface | SPI-compatible serial bus (Mode 0,0), with dedicated SI, SO, SCK, CS, WP, HOLD, VCC, VSS |
| Max Clock Frequency | 10 MHz at VCC = 4.5–5.5 V; reduced to 5 MHz at 2.5–4.5 V - defines maximum throughput for read/write sequences |
| Page Size | 32 bytes - limits contiguous write length without crossing physical page boundary; crossing causes wraparound overwrite |
| Write Cycle Time | ≤5 ms self-timed internal erase/write - determines minimum interval between successive write commands |
| Endurance & Retention | >1,000,000 erase/write cycles at +25°C/5.5V; >200 years data retention - validated for automotive lifecycle requirements |
| Temperature Range | Extended (E): –40°C to +125°C - qualified per AEC-Q100 Grade 1, suitable for under-hood applications |
Pinout & Package
25LC320AXT-E/ST uses an 8-lead TSSOP package (3.0 mm × 4.4 mm, 0.65 mm pitch), RoHS-compliant, with exposed pad optional (not electrically connected). Pin 1 is marked via notch or bevel; pin numbering follows standard TSSOP convention (counterclockwise from top-left corner).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select Input | Active-low enables SPI communication; rising edge after valid write sequence initiates internal write cycle |
| SO | Serial Data Output | Tri-state output delivering read data MSB-first on falling SCK edge; enters high-Z when CS high or HOLD low |
| WP | Write-Protect Pin | Hardware lock for STATUS register nonvolatile bits when WPEN=1; no effect if WPEN=0 or WP high |
| VSS | Ground Reference | Primary return path for all I/O and core circuitry; must be low-impedance connection in layout |
| SI | Serial Data Input | Latches instruction/address/data on rising SCK edge; accepts 8-bit opcodes (e.g., 0x03 for READ, 0x02 for WRITE) |
| SCK | Serial Clock Input | Synchronizes all SPI transfers; timing constraints (e.g., THI/TLO ≥50 ns at 5.5 V) govern max clock rate |
| HOLD | Hold Input | Suspends active SPI sequence without reset; requires low-to-high transition while SCK is low to resume |
| VCC | Supply Voltage | 2.5–5.5 V operating range; internal voltage regulation enables stable EEPROM operation across rail variation |
Key Features
| Feature | Design Value |
|---|---|
| Block Write Protection | Selectable via BP1/BP0 bits: protect none, upper 1/4 (0xC00–0xFFF), upper 1/2 (0x800–0xFFF), or full array (0x000–0xFFF) |
| Power-On Data Protection | Write enable latch resets at power-up; WP pin and STATUS register prevent accidental writes during brownout or reset |
| Sequential Read Mode | Auto-incrementing address pointer allows continuous read across 0x000–0xFFF; rolls over to 0x000 after 0xFFF |
| HOLD Functionality | Pauses SPI transfer mid-sequence; preserves internal state and allows host to service higher-priority interrupts |
| ESD Robustness | ≥4 kV HBM rating on all pins - ensures reliability in automotive assembly and field environments |
Applications
| Automotive Body Control Unit (BCU) | Industrial PLC Configuration Storage |
|---|---|
Use Scenario: Storing calibrated sensor offsets, door lock settings, and lighting profiles in vehicle BCU modules subject to thermal cycling and EMI. IC Role / Device Role / Timing Role: Nonvolatile configuration memory interfacing with PIC® MCU via SPI; retains data across ignition cycles and battery disconnects. Use Value: AEC-Q100 qualification and >125°C operation ensure functional integrity in under-dash mounting; 32-byte page writes minimize firmware overhead during parameter updates. |
Use Scenario: Holding ladder logic parameters, I/O mapping, and calibration coefficients in modular PLC backplanes with limited board space. IC Role / Device Role / Timing Role: SPI EEPROM providing persistent storage for runtime-configurable firmware modules; accessed during boot and field reprogramming. Use Value: 8-lead TSSOP footprint saves PCB area vs. SOIC; HOLD pin enables deterministic interrupt handling during multi-master SPI arbitration. |
| Medical Infusion Pump Calibration | Smart Energy Meter Firmware Patch Storage |
Use Scenario: Archiving dose calibration tables, motor tuning values, and safety-critical fault logs in Class II medical devices requiring long-term data integrity. IC Role / Device Role / Timing Role: Secure, tamper-resistant memory storing FDA-mandated traceability data; write-protected via WP pin and BP bits during normal operation. Use Value: >200-year data retention meets ISO 13485 archival requirements; >1M endurance supports daily recalibration cycles over 10+ year device life. |
Use Scenario: Storing firmware patch binaries and cryptographic keys in utility-grade meters deployed in outdoor enclosures with wide ambient temperature swings. IC Role / Device Role / Timing Role: Field-upgradable memory holding encrypted OTA update payloads; accessed only during secure boot verification. Use Value: Extended temperature range (–40°C to +125°C) guarantees reliable read/write at enclosure extremes; hardware write protection prevents unauthorized key modification. |
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 | Industrial temp grade (–40°C to +85°C); identical electrical specs and pinout | Not qualified for automotive extended-temp environments; lower cost for non-automotive industrial use | Select when AEC-Q100 and +125°C operation are not required - reduces BOM cost without design change |
| AT25DF321A-MAU-T | 32-Mbit density (10× larger), quad SPI interface, 8-pin SOIC package; no HOLD or WP pin | Supports faster bulk reads via quad mode but lacks hardware write protection and HOLD suspend capability | Choose for high-throughput firmware storage where security and interrupt latency are secondary to capacity and speed |
Compared with 25LC320AXT-E/ST, the 25LC320AT-I/ST offers identical functionality at lower temperature grade and cost, while the AT25DF321A-MAU-T trades hardware protection and suspend features for higher density and quad-speed access - making the 25LC320AXT-E/ST optimal for safety-critical, interrupt-sensitive automotive and industrial control.
Availability
25LC320AXT-E/ST is available at Aetrix Electronics and suitable for automotive body electronics, industrial programmable logic controllers, medical infusion pump calibration, and smart energy meter firmware storage requiring stable component supply across extended temperature ranges and long product lifecycles.
Supply support for 25LC320AXT-E/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, serving automotive, industrial, consumer, and communications markets with vertically integrated silicon and development tools.
The 25LC320A family is designed specifically for robust, low-power serial data storage in harsh environments - emphasizing AEC-Q100 qualification, hardware write protection, and SPI interoperability with PIC® and other embedded controllers.
FAQ
What is the operating voltage range for the 25LC320AXT-E/ST?
The 25LC320AXT-E/ST operates from 2.5 V to 5.5 V. This range enables compatibility with both 3.3 V and 5 V microcontroller systems. At VCC < 2.5 V, the device is not guaranteed to function; at VCC > 5.5 V, absolute maximum ratings are exceeded. The 25LC320AXT-E/ST datasheet specifies DC characteristics across this full range, including reduced clock frequency (3 MHz) below 2.5 V.
Does the 25LC320AXT-E/ST support page write operations, and what is the maximum page size?
Yes, the 25LC320AXT-E/ST supports page write operations with a fixed 32-byte page size. Up to 32 bytes can be written in a single transaction, provided all addresses reside within the same physical page (e.g., 0x000–0x01F, 0x020–0x03F). Crossing a page boundary causes wraparound - writing byte 33 to address 0x020 overwrites address 0x000, not 0x020. This behavior is inherent to the 25LC320AXT-E/ST architecture and must be managed in firmware.
How does hardware write protection work on the 25LC320AXT-E/ST?
Hardware write protection on the 25LC320AXT-E/ST requires both WPEN=1 in the STATUS register *and* the WP pin held low. When both conditions are met, writes to nonvolatile STATUS bits (BP0, BP1, WPEN) are blocked - though array writes remain enabled unless BP bits are set. If WP is high or WPEN=0, hardware protection is disabled and all STATUS bits are writable. This dual-condition design allows safe installation in systems with grounded WP pins.
What is the purpose of the HOLD pin on the 25LC320AXT-E/ST, and how must it be used?
The HOLD pin on the 25LC320AXT-E/ST suspends ongoing SPI communication without resetting the internal state - allowing the host MCU to service time-critical interrupts and resume exactly where it left off. To invoke HOLD, the pin must be pulled low while SCK is low; to resume, it must be raised high while SCK remains low. Violating this timing causes delayed resumption until the next SCK falling edge. SO immediately enters high-Z on HOLD assertion.
Is the 25LC320AXT-E/ST pin-compatible with other members of the 25XX320A family?
Yes, the 25LC320AXT-E/ST shares identical pinout, package dimensions, and SPI protocol with all 25XX320A variants (e.g., 25AA320A, 25LC320A in SOIC, MSOP, TDFN). Differences are limited to VCC range (2.5–5.5 V vs. 1.8–5.5 V), temperature grade (E vs. I), and marking - not pin assignment or electrical interface. The 25LC320AXT-E/ST TSSOP footprint matches the 25LC320AT-I/ST TSSOP, enabling drop-in replacement where temperature requirements align.
25LC320AXT-E/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:
- Not 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:
- 2.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-TSSOP
25LC320AXT-E/ST FAQ
1.How can I place an order for 25LC320AXT-E/ST through Aetrix?
Please submit a Request for Quotation (RFQ) for 25LC320AXT-E/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 25LC320AXT-E/ST reliable?
The price and inventory of 25LC320AXT-E/ST are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 25LC320AXT-E/ST is usually 5 days.
3.What payment methods are accepted for 25LC320AXT-E/ST?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 25LC320AXT-E/ST transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 25LC320AXT-E/ST?
25LC320AXT-E/ST orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 25LC320AXT-E/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 25LC320AXT-E/ST?
For technical support, including 25LC320AXT-E/ST datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 25LC320AXT-E/ST requirements.
6.How does Aetrix verify that 25LC320AXT-E/ST is sourced from the original manufacturer or authorized distributors?
All 25LC320AXT-E/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 25LC320AXT-E/ST meets industry standards.
7.What is the process for return or replacement of 25LC320AXT-E/ST?
All 25LC320AXT-E/ST units undergo pre-shipment inspection (PSI). If there is an issue with 25LC320AXT-E/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 25LC320AXT-E/ST part is unused and in its original packaging.
Return procedure for 25LC320AXT-E/ST:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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