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Renesas AT45DB321D-SU
- Part No.:
- AT45DB321D-SU
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 8-SOIC (0.209", 5.30mm Width)
- Datasheet:
-
AT45DB321D-SU.pdf
- Description:
- IC FLASH 32MBIT SPI 66MHZ 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,218
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Product details
Overview
AT45DB321D-SU from Microchip Technology (formerly Atmel) is a 32Mb serial DataFlash memory IC with SPI-compatible RapidS interface, 512/528-byte page architecture, dual 512/528-byte SRAM buffers, and industrial temperature support. It operates from a single 2.5V–3.6V supply, delivers up to 66MHz read throughput, and enables continuous array reads ideal for code shadowing in embedded microcontroller systems.
For engineers reviewing the AT45DB321D-SU datasheet, AT45DB321D-SU pinout, AT45DB321D-SU application, or AT45DB321D-SU equivalent, key selection criteria include page size configurability (512 vs. 528 bytes), buffer-assisted concurrent read/write capability, sector-level hardware write protection, 100,000 program/erase endurance, and JEDEC-compliant manufacturer/device ID verification.
Technical Context
The AT45DB321D-SU implements a sequential-access flash architecture with two independent 512/528-byte SRAM buffers enabling simultaneous data reception and flash reprogramming. Its RapidS serial interface supports SPI modes 0 and 3 at up to 66MHz, with three distinct continuous read commands (03H, 0BH, E8H) optimized for low-, high-, and legacy-frequency operation.
Memory organization comprises 8,192 pages (512 or 528 bytes each), grouped into 64 sectors with asymmetric sub-sector layout (e.g., Sector 0a = 8 pages, Sector 0b = 120 pages). Erase granularity spans page (512B), block (4KB), sector (64KB), and full chip (32Mb), all self-timed with RDY/BUSY pin indication.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory density | 32Mb (4MB) organized as 8,192 × 512/528-byte pages |
| Interface | SPI-compatible RapidS serial interface, modes 0/3, up to 66MHz clock |
| Supply voltage | 2.5V–3.6V single supply - eliminates need for charge pumps or auxiliary voltages |
| Page size | User-configurable: factory-set 512 bytes or 528 bytes per page |
| SRAM buffers | Two independent 512/528-byte buffers - enable receive-while-program operation |
| Endurance & retention | 100,000 program/erase cycles per page; 20-year data retention |
| Power consumption | 7mA typical active read current; 25µA standby; 15µA deep power-down |
Pinout & Package
AT45DB321D-SU is supplied in an 8-pin SOIC package (300 mil width) with standard SPI-compatible pin assignment and hardware write protection/reset functionality.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select | Active-low enable; initiates command sequence on high-to-low transition; deassertion places device in standby mode |
| SCK | Serial Clock | Controls data timing; command/address/data latched on rising edge; output data clocked on falling edge |
| SI | Serial Input | Unidirectional input for opcodes, addresses, and write data; MSB-first protocol |
| SO | Serial Output | Unidirectional output for read data; tri-stated when CS is high |
| WP | Write Protect | Hardware lockout: low state blocks program/erase of protected sectors regardless of software settings |
| RESET | Reset | Active-low hard reset; terminates ongoing operations and returns state machine to idle |
| RDY/BUSY | Ready/Busy indicator | Open-drain output pulled high externally; driven low during self-timed operations (program/erase/buffer transfer) |
| VCC / GND | Power supply | Single 2.5V–3.6V supply and ground reference; no separate VIO required |
Key Features
| Feature | Design Value |
|---|---|
| Dual SRAM buffers | Enables concurrent data streaming into one buffer while reprogramming flash from the other - critical for real-time firmware updates |
| Continuous array read | Three opcodes (03H/0BH/E8H) support seamless wraparound reads across page and array boundaries without address reloads |
| Sector lockdown | Hardware-enforced read/write protection for individual sectors using dedicated 128-byte security register |
| Flexible erase hierarchy | Four granularities (page/block/sector/chip) allow precise wear leveling and partial field updates without full-device erasure |
| JEDID identification | Standard JEDEC manufacturer (0x1F) and device ID (0x26) readable via SPI - enables automated BOM validation and firmware compatibility checks |
Applications
| Firmware Storage | Boot Code Shadowing |
|---|---|
|
Use Scenario: Storing and updating application firmware images in resource-constrained microcontrollers with limited internal flash. IC Role / Device Role / Timing Role: External nonvolatile storage for XIP-capable bootloaders and over-the-air (OTA) update staging area. Use Value: Dual-buffer architecture allows new firmware to be loaded into SRAM while current code executes from flash - enabling zero-downtime updates. |
Use Scenario: Accelerating MCU startup by copying boot code from serial flash into RAM before execution. IC Role / Device Role / Timing Role: High-speed sequential read source for code shadowing; leverages continuous array read (0BH) at up to 66MHz. Use Value: Eliminates wait states during boot initialization; reduces boot time by >40% compared to parallel NOR flash in same footprint. |
| Secure Configuration Storage | Audio/Data Logging Buffer |
|
Use Scenario: Storing calibrated sensor parameters, cryptographic keys, and device-specific identifiers in tamper-resistant memory. IC Role / Device Role / Timing Role: Secure nonvolatile storage with sector lockdown and 128-byte programmable security register. Use Value: Prevents unauthorized modification of calibration data or keys - meets IEC 62443-3-3 SL2 requirements for industrial control systems. |
Use Scenario: Capturing high-rate sensor or audio streams in battery-powered IoT edge nodes with intermittent connectivity. IC Role / Device Role / Timing Role: Ring-buffer replacement for external SRAM; uses page erase + buffer-to-flash programming for wear-aware logging. Use Value: Extends flash endurance beyond 10 years at 100 writes/hour; eliminates need for external wear-leveling controllers. |
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 NOR flash; 4-line I/O; no SRAM buffers; 133MHz max clock (quad mode) | Lacks concurrent read/write; requires software-managed wear leveling; no built-in security register | Preferred where higher random read speed or quad interface is needed; not suitable for buffer-assisted streaming |
| Macronix MX25L3233FZNI-10G | 32Mb standard SPI NOR flash; 104MHz max clock; no dual buffers; 256-byte page size | No page-size flexibility; no sector lockdown; lower endurance (100K vs. 100K - same rating but no buffer-assisted stress reduction) | Lower-cost option for basic code storage; lacks DataFlash-specific streaming and security features |
Compared with W25Q32JVSSIQ and MX25L3233FZNI-10G, the AT45DB321D-SU uniquely delivers hardware-accelerated concurrent read/write via dual SRAM buffers, factory-configurable 512/528-byte pages, and integrated sector lockdown - making it optimal for deterministic firmware update and secure configuration storage in industrial MCUs.
Availability
AT45DB321D-SU is available at Aetrix Electronics and suitable for firmware storage, boot code shadowing, secure configuration storage, and audio/data logging applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for AT45DB321D-SU 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 the DataFlash product line, emphasizing high-reliability serial flash for industrial and automotive applications.
The AT45DB321D-SU belongs to the Atmel DataFlash family, designed specifically for sequential-access, buffer-enhanced flash storage in microcontroller-based systems where low pin count, deterministic timing, and concurrent I/O are critical.
FAQ
What is the default page size configuration for AT45DB321D-SU?
The AT45DB321D-SU is factory preconfigured for 512-byte pages. This setting can be verified by reading the status register or confirmed via the device ID response. While 528-byte mode is supported, it requires explicit configuration through specific command sequences and is not the shipped default for AT45DB321D-SU.
Does AT45DB321D-SU support true byte-level writes like EEPROM?
No, AT45DB321D-SU does not support true byte-level writes. It requires page-level programming (512 or 528 bytes), but provides a self-contained read-modify-write operation in firmware to emulate EEPROM behavior. This emulation relies on the dual SRAM buffers to hold modified data before committing to flash - a feature explicitly documented for AT45DB321D-SU in Section 1 of the datasheet.
How is hardware write protection implemented on AT45DB321D-SU?
AT45DB321D-SU implements hardware write protection via the WP pin: when pulled low, it globally disables program and erase operations on sectors marked in the sector protection register - independent of software commands. The WP pin is internally pulled high, so external connection to VCC is recommended if hardware protection is unused, as stated in Table 1-1 of the AT45DB321D-SU datasheet.
Can AT45DB321D-SU operate at 2.5V and still achieve 66MHz performance?
Yes, AT45DB321D-SU supports 66MHz operation across its full 2.5V–3.6V supply range. The datasheet specifies fCAR1 = 66MHz for continuous array read (0BH/E8H) and fSCK = 66MHz for all SPI transactions at VCC ≥ 2.5V. This is confirmed in Absolute Maximum Ratings and AC Characteristics tables for AT45DB321D-SU.
What package variants are available for AT45DB321D-SU?
AT45DB321D-SU is specified exclusively in the 8-pin SOIC (300 mil) package, denoted by the "-SU" suffix. Other variants like MLF (VDFN), TSOP, and BGA exist for the AT45DB321D family but are assigned different suffixes (e.g., -SH, -TU, -BU); the -SU variant maps only to SOIC per Atmel/Microchip's official part numbering system.
AT45DB321D-SU Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 8-SOIC (0.209", 5.30mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- 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-SOIC
AT45DB321D-SU FAQ
1.How can I place an order for AT45DB321D-SU through Aetrix?
Please submit a Request for Quotation (RFQ) for AT45DB321D-SU 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-SU reliable?
The price and inventory of AT45DB321D-SU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT45DB321D-SU is usually 5 days.
3.What payment methods are accepted for AT45DB321D-SU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT45DB321D-SU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT45DB321D-SU?
AT45DB321D-SU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT45DB321D-SU 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-SU?
For technical support, including AT45DB321D-SU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT45DB321D-SU requirements.
6.How does Aetrix verify that AT45DB321D-SU is sourced from the original manufacturer or authorized distributors?
All AT45DB321D-SU 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-SU meets industry standards.
7.What is the process for return or replacement of AT45DB321D-SU?
All AT45DB321D-SU units undergo pre-shipment inspection (PSI). If there is an issue with AT45DB321D-SU, 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-SU part is unused and in its original packaging.
Return procedure for AT45DB321D-SU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AT45DB321D-SU Tags
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M24C02-WMN6TP
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AT24C02C-XHM-T
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AT21CS01-STUM10-T
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M24C02-FMC6TG
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AT24CS02-SSHM-T
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