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Microchip Technology AT45DB321D-MWU
- Part No.:
- AT45DB321D-MWU
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-VDFN Exposed Pad
- Datasheet:
-
AT45DB321D-MWU.pdf
- Description:
- IC FLASH 32MBIT SPI 66MHZ 8VDFN
- Quantity:
- Payment:
- Shipping:
Inventory:3,066
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Product details
Overview
AT45DB321D-MWU from Microchip Technology (formerly Atmel) is a 32Mb serial DataFlash memory IC with SPI-compatible RapidS interface, 66MHz max clock, dual 512/528-byte SRAM buffers, and flexible page/block/sector/chip erase architecture. It operates from a single 2.5V–3.6V supply and supports code shadowing in embedded boot loaders.
For engineers reviewing the AT45DB321D-MWU datasheet, AT45DB321D-MWU pinout, AT45DB321D-MWU application, or AT45DB321D-MWU equivalent, key selection criteria include buffer-assisted concurrent read/write capability, hardware write protection (WP), RDY/BUSY status signaling, industrial temperature range (–40°C to +85°C), and JEDEC-compliant ID read support.
Technical Context
The AT45DB321D-MWU implements a sequential-access flash architecture with two independent 512/528-byte SRAM buffers enabling simultaneous data reception and main memory reprogramming. Its RapidS interface supports SPI modes 0 and 3 at up to 66MHz, with continuous array read bypassing buffers for zero-latency code execution.
Memory organization comprises 8,192 pages (512 or 528 bytes each), grouped into sectors (64KB), blocks (4KB), and sub-sectors (e.g., Sector 0a = 4KB). Erase operations are fully self-timed and supported at page (512B), block (4KB), sector (64KB), and chip (32Mb) levels - all without external high-voltage programming.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory capacity | 32Mb (34,603,008 bits), organized as 8,192 × 512/528-byte pages - enables compact firmware storage with configurable granularity. |
| Interface speed | Up to 66MHz SCK (RapidS mode), supporting high-throughput firmware updates and real-time streaming applications. |
| Supply voltage | 2.5V–3.6V single supply - eliminates need for level shifters in 3.3V microcontroller systems. |
| Active current | 7mA typical read current - minimizes power budget impact during boot-time code shadowing. |
| Data retention | 20 years - ensures long-term reliability in unattended industrial logging and medical device firmware storage. |
| Endurance | 100,000 program/erase cycles per page - supports frequent field-upgrade scenarios in IoT edge nodes. |
| Temperature range | –40°C to +85°C industrial grade - validated for operation in automotive infotainment head units and factory automation controllers. |
Pinout & Package
AT45DB321D-MWU uses an 8-pin MLF (VDFN) package (3mm × 4mm, 0.5mm pitch) with exposed metal pad (floating or GND-connected). Pin functions align with standard SPI+control interface.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select | Active-low enable; initiates command sequence on falling edge and terminates on rising edge - critical for multi-device SPI bus arbitration. |
| SCK | Serial Clock | Master-generated clock; latches SI on rising edge, clocks SO on falling edge - defines timing margin for 66MHz operation. |
| SI | Serial Input | Command, address, and data input path - accepts opcodes (e.g., 0BH for high-speed read) and 24-bit address sequences. |
| SO | Serial Output | Data output path; tri-stated when CS is high - allows shared bus topology with other SPI peripherals. |
| WP | Write Protect | Hardware-level sector lock override; prevents accidental erase/program even if software protection is disabled - essential for secure bootloader regions. |
| RESET | Reset | Asynchronous abort of ongoing program/erase; forces idle state - used for recovery after power brownout or watchdog timeout. |
| RDY/BUSY | Ready/Busy Status | Open-drain output indicating internal self-timed operation progress - enables polling instead of fixed delays in firmware drivers. |
| VCC / GND | Power / Ground | Single 2.5–3.6V supply pair; decoupling required within 10mm of pins - ensures stable operation during high-speed burst reads. |
Key Features
| Feature | Design Value |
|---|---|
| Dual SRAM buffers (512/528 bytes) | Enables pipelined operation: receive new data into one buffer while programming flash from the other - reduces effective write latency by >50% vs. single-buffer devices. |
| Continuous array read (E8H/0BH/03H) | Supports seamless code shadowing from flash to RAM without address reinitialization - eliminates page-boundary stalls during MCU instruction fetch. |
| Flexible page size (512 or 528 bytes) | Factory-configurable to match legacy EEPROM emulation requirements (512B) or optimized firmware alignment (528B with spare area). |
| 128-byte security register | Contains 64-byte user-programmable space + 64-byte unique device ID - enables secure firmware binding and anti-cloning in certified medical devices. |
| Hardware + software protection | Combines WP pin assertion with sector lockdown commands - provides defense-in-depth against malicious or erroneous firmware overwrite. |
Applications
| Firmware Boot Storage | Industrial Data Logger |
|---|---|
|
Use Scenario: Storing boot code for ARM Cortex-M4 microcontrollers in motor drive inverters requiring cold-start reliability. IC Role / Device Role / Timing Role: Primary nonvolatile firmware repository with continuous array read enabling zero-wait-state instruction fetch during startup. Use Value: Eliminates external parallel NOR flash, reducing PCB layer count and EMI emissions via low-pin-count SPI interface. |
Use Scenario: Capturing sensor readings (temperature, vibration) at 1kHz in predictive maintenance gateways deployed in oil refineries. IC Role / Device Role / Timing Role: High-endurance data ring buffer supporting 100,000+ write cycles per page across rotating log sectors. Use Value: Sustains 10-year field life under continuous write stress without wear leveling firmware overhead. |
| Secure OTA Update Cache | Medical Device Configuration Store |
|
Use Scenario: Caching signed firmware images received over BLE/Wi-Fi before authenticated installation in portable ultrasound scanners. IC Role / Device Role / Timing Role: Tamper-resistant staging area using sector lockdown and 128-byte security register for cryptographic key binding. Use Value: Prevents rollback attacks and unauthorized image injection by enforcing hardware-enforced write protection during update validation. |
Use Scenario: Storing calibrated transducer parameters and regulatory audit logs in FDA-cleared patient monitors. IC Role / Device Role / Timing Role: JEDEC ID-verified, RoHS-compliant nonvolatile store with 20-year data retention for compliance traceability. Use Value: Meets IEC 62304 §5.5.3 requirements for permanent configuration storage without battery backup. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial flash memory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Winbond W25Q32JVSSIQ | 32Mb Quad SPI (QSPI) with 4-line I/O; no SRAM buffers; 133MHz max clock; 1.8V–3.6V supply. | Lacks concurrent buffer operation; requires QSPI controller; better suited for high-bandwidth graphics/textures than firmware shadowing. | Choose for cost-sensitive consumer electronics where QSPI bandwidth outweighs buffer-assisted latency benefits. |
| Macronix MX25L3233FZBI-10G | 32Mb standard SPI; no SRAM buffers; 104MHz max clock; 2.7V–3.6V supply; built-in ECC. | Higher clock rate but no dual-buffer overlap; ECC supports soft-error correction in radiation-prone aerospace environments. | Prefer when system-level error resilience is prioritized over pipelined write throughput in avionics data recorders. |
Compared with W25Q32JVSSIQ and MX25L3233FZBI-10G, the AT45DB321D-MWU uniquely delivers true concurrent read-while-write via dedicated SRAM buffers - a deterministic latency advantage for real-time embedded boot and logging where interrupt response time is bounded.
Availability
AT45DB321D-MWU is available at Aetrix Electronics and suitable for firmware boot storage, industrial data logging, secure OTA update caching, and medical device configuration storage requiring stable component supply and long-term lifecycle assurance.
Supply support for AT45DB321D-MWU 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 acquired Atmel in 2016 and maintains full support for the DataFlash product family, emphasizing reliability, longevity, and industrial-grade qualification.
The AT45DB321D-MWU belongs to the Atmel DataFlash® series, designed specifically for embedded systems needing high-density serial flash with deterministic latency, hardware security, and simplified layout - not general-purpose memory.
FAQ
What is the maximum clock frequency supported by the AT45DB321D-MWU during continuous array read?
The AT45DB321D-MWU supports up to 66MHz SCK frequency for continuous array read using opcodes 0BH (high-frequency mode) or E8H (legacy mode), as specified by fCAR1 in the datasheet. This enables real-time code shadowing without wait states in Cortex-M microcontrollers. The AT45DB321D-MWU achieves this performance while maintaining full compatibility with standard SPI mode 0 and mode 3 timing.
Does the AT45DB321D-MWU require external high-voltage programming circuitry?
No, the AT45DB321D-MWU performs all program and erase operations using only its 2.5V–3.6V supply rail - no external VPP or charge pump is needed. All internal timing is self-contained, with RDY/BUSY signaling indicating completion. This simplifies board design and improves system reliability compared to legacy parallel flash devices. The AT45DB321D-MWU eliminates high-voltage generation entirely.
How does the dual-buffer architecture of the AT45DB321D-MWU improve write performance?
The AT45DB321D-MWU's two independent 512/528-byte SRAM buffers allow overlapping data reception (into one buffer) with flash programming (from the other), cutting effective write latency by up to 60% versus single-buffer serial flash. This pipelining is transparent to firmware and requires no special driver logic. The AT45DB321D-MWU leverages this to sustain 66MHz read throughput while writing new data concurrently.
Can the AT45DB321D-MWU be used as a direct replacement for EEPROM in byte-alterable applications?
Yes - the AT45DB321D-MWU supports EEPROM emulation via a three-step read-modify-write sequence managed entirely in firmware, eliminating need for external EEPROM. Its 100,000-cycle endurance per page and 20-year retention meet or exceed industrial EEPROM specs. Unlike true EEPROM, the AT45DB321D-MWU requires page-level writes but delivers higher density and lower pin count.
What package type is used for the AT45DB321D-MWU, and is thermal pad connection required?
The AT45DB321D-MWU uses an 8-pin MLF (VDFN) package (3mm × 4mm, 0.5mm pitch) with an exposed metal pad on the bottom. The pad is electrically floating by default and may be left unconnected or tied to GND for improved thermal dissipation - no thermal vias or solder mask opening is mandatory. This compact RoHS-compliant package supports high-density PCB layouts typical in medical and industrial modules.
AT45DB321D-MWU Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-VDFN Exposed Pad
- Packaging:
- Tray
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- FLASH
- Technology:
- FLASH
- Memory Size:
- 32Mbit
- Memory Organization:
- 528 Bytes x 8192 pages
- Memory Interface:
- SPI
- Clock Frequency:
- 66 MHz
- Write Cycle Time - Word, Page:
- 6ms
- Access Time:
- -
- Voltage - Supply:
- 2.7V ~ 3.6V
- Operating Temperature:
- -40°C ~ 85°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-VDFN (6x8)
AT45DB321D-MWU FAQ
1.How can I place an order for AT45DB321D-MWU through Aetrix?
Please submit a Request for Quotation (RFQ) for AT45DB321D-MWU 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 AT45DB321D-MWU reliable?
The price and inventory of AT45DB321D-MWU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT45DB321D-MWU is usually 5 days.
3.What payment methods are accepted for AT45DB321D-MWU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT45DB321D-MWU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT45DB321D-MWU?
AT45DB321D-MWU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT45DB321D-MWU 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 AT45DB321D-MWU?
For technical support, including AT45DB321D-MWU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT45DB321D-MWU requirements.
6.How does Aetrix verify that AT45DB321D-MWU is sourced from the original manufacturer or authorized distributors?
All AT45DB321D-MWU 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 AT45DB321D-MWU meets industry standards.
7.What is the process for return or replacement of AT45DB321D-MWU?
All AT45DB321D-MWU units undergo pre-shipment inspection (PSI). If there is an issue with AT45DB321D-MWU, 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 AT45DB321D-MWU part is unused and in its original packaging.
Return procedure for AT45DB321D-MWU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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