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Renesas AT45DB321D-SU-SL955
- Part No.:
- AT45DB321D-SU-SL955
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 8-SOIC (0.209", 5.30mm Width)
- Datasheet:
-
AT45DB321D-SU-SL955.pdf
- Description:
- IC FLASH 32MBIT SPI 66MHZ 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,121
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Product details
Overview
AT45DB321D-SU-SL955 from Microchip Technology (acquired 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 code shadowing in embedded microcontroller systems.
For engineers reviewing the AT45DB321D-SU-SL955 datasheet, AT45DB321D-SU-SL955 pinout, AT45DB321D-SU-SL955 application, or AT45DB321D-SU-SL955 equivalent, key selection criteria include page-size configurability (512 vs. 528 bytes), hardware write protection via WP pin, RDY/BUSY open-drain status signaling, and sector lockdown for secure firmware storage.
Technical Context
The AT45DB321D-SU-SL955 implements a sequential-access flash architecture with two independent SRAM buffers that support concurrent data reception while reprogramming the main array - enabling continuous streaming without CPU intervention. Its RapidS interface supports SPI modes 0 and 3 at up to 66MHz, with three distinct continuous read opcodes (03H, 0BH, E8H) optimized for low-, high-, and legacy-frequency operation.
Memory organization comprises 8,192 pages of 512 or 528 bytes each, grouped into sectors (64KB), blocks (4KB), and pages (512/528B), allowing granular erase control. All program/erase operations are self-timed, and the device integrates a 128-byte security register with 64-byte user-programmable space and unique 64-byte device ID for traceability.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Capacity | 32Mb (34,603,008 bits) organized as 8,192 pages × 512 or 528 bytes |
| Interface Speed | Up to 66MHz SCK for continuous reads (0BH/E8H); 33MHz for 03H mode |
| Supply Voltage | 2.5V–3.6V or 2.7V–3.6V single supply - no high-voltage programming required |
| Power Consumption | 7mA typical active read current; 25µA standby; 15µA deep power-down |
| Erase Endurance | 100,000 program/erase cycles per page minimum |
| Data Retention | 20 years at industrial temperature range (−40°C to +85°C) |
| Security Features | 128-byte security register (64-byte user space + 64-byte unique ID) and sector lockdown |
Pinout & Package
AT45DB321D-SU-SL955 is packaged in an 8-pin SOIC (Small Outline Integrated Circuit) with standard lead pitch and RoHS-compliant green finish. Pin functions are electrically defined and validated per Atmel/Microchip datasheet 3597Q–DFLASH–6/11.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select | Active-low enable; initiates command sequence on high-to-low transition and terminates on low-to-high |
| SCK | Serial Clock | Controls data timing; SI latched on rising edge, SO clocked out on falling edge |
| SI | Serial Input | Command, address, and data input path; MSB-first protocol |
| SO | Serial Output | Data output path; tri-stated when CS is high |
| WP | Write Protect | Hardware lock for sector protection; overrides software protection when asserted low |
| RESET | Reset | Active-low hard reset; terminates ongoing operations and returns state machine to idle |
| RDY/BUSY | Ready/Busy Status | Open-drain output pulled high externally; driven low during self-timed operations |
| VCC / GND | Power Supply | Single 2.5V–3.6V supply with dedicated ground reference; no internal regulation required |
Key Features
| Feature | Design Value |
|---|---|
| Dual SRAM Buffers | Two independent 512/528-byte buffers enable simultaneous receive-and-program operation - eliminates CPU polling during flash writes |
| Configurable Page Size | Factory-set 512-byte or 528-byte pages; determines address bit allocation (A21–A0 vs. PA12–PA0/BA9–BA0) and buffer addressing scheme |
| Flexible Erase Granularity | Page (512B), block (4KB), sector (64KB), or full-chip (32Mb) erase - optimizes wear leveling and firmware update efficiency |
| Continuous Read Modes | Three opcodes (03H, 0BH, E8H) support seamless wraparound reads across page and array boundaries - ideal for boot code shadowing |
| Hardware + Software Security | WP pin provides physical write lock; sector lockdown + 128-byte security register enable secure bootloader and credential storage |
Applications
| Industrial HMI Firmware Storage | Medical Device Boot Image Caching |
|---|---|
Use Scenario: Storing GUI assets, configuration profiles, and firmware updates in panel-mounted HMIs with limited PCB real estate. IC Role / Device Role / Timing Role: Serial NOR replacement providing nonvolatile storage with faster sequential read than parallel flash and lower pin count than eMMC. Use Value: 66MHz continuous read enables rapid UI asset loading; dual buffers allow background firmware download while system remains responsive. |
Use Scenario: Caching boot images and calibration tables in portable diagnostic equipment requiring FDA-compliant data integrity. IC Role / Device Role / Timing Role: Secure, long-retention storage for certified boot code with hardware write protection and unique device ID for audit trails. Use Value: Sector lockdown prevents unauthorized modification of boot partition; 20-year data retention meets medical device lifecycle requirements. |
| Automotive Telematics Log Buffer | IoT Edge Gateway Configuration Vault |
Use Scenario: Capturing CAN bus diagnostics and GPS logs in vehicle telematics units operating across extended temperature ranges. IC Role / Device Role / Timing Role: High-reliability sequential log storage with RDY/BUSY signaling to coordinate MCU logging tasks without polling overhead. Use Value: Industrial −40°C to +85°C rating ensures operation under hood conditions; 100K-cycle endurance supports frequent log rotation. |
Use Scenario: Storing encrypted network credentials, OTA update manifests, and device-specific keys in battery-powered smart gateways. IC Role / Device Role / Timing Role: Low-power configuration vault using deep power-down (15µA) between MQTT publish cycles and hardware-protected key storage. Use Value: WP pin + sector lockdown isolates critical keys from firmware update routines; 25µA standby extends battery life in always-on deployments. |
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; 4-line I/O; no SRAM buffers; fixed 4KB sectors | Lacks dual-buffer streaming and configurable page size; requires different driver logic for erase/write | Preferred where quad-speed random access is needed over sequential streaming |
| Macronix MX25L3233FZBI-10G | 32Mb standard SPI NOR; 3V supply; no built-in buffers; 4KB/64KB/512KB erase blocks | No RDY/BUSY pin; relies on status register polling; no hardware write protect pin | Suitable for cost-sensitive designs where buffer concurrency and WP pin are not required |
Compared with AT45DB321D-SU-SL955, W25Q32JVSSIQ offers higher random read bandwidth but lacks concurrent buffer operation, while MX25L3233FZBI-10G reduces BOM cost but increases firmware complexity due to polling-based status management and absence of hardware write protection.
Availability
AT45DB321D-SU-SL955 is available at Aetrix Electronics and suitable for industrial HMI firmware storage, medical device boot image caching, automotive telematics log buffering, and IoT edge gateway configuration vault applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for AT45DB321D-SU-SL955 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 technical and supply chain ownership of the DataFlash product line, including legacy Atmel-branded devices like the AT45DB321D-SU-SL955.
The AT45DB321D-SU-SL955 belongs to the Atmel DataFlash family, designed specifically for high-density, low-pin-count, sequential-access flash storage in resource-constrained embedded systems where SPI simplicity and streaming performance outweigh random-access needs.
FAQ
What voltage range does the AT45DB321D-SU-SL955 support?
The AT45DB321D-SU-SL955 operates from a single supply of 2.5V–3.6V or 2.7V–3.6V - no external voltage regulators or charge pumps are required for programming or reading. This wide range accommodates both 2.5V and 3.3V system rails, and the device guarantees full functionality across the entire industrial temperature range (−40°C to +85°C) within these voltages.
Does the AT45DB321D-SU-SL955 support true SPI mode compatibility?
Yes, the AT45DB321D-SU-SL955 supports SPI modes 0 and 3 per its RapidS interface specification. It uses standard CPOL/CPHA definitions: mode 0 (CPOL=0, CPHA=0) samples SI on rising SCK and outputs SO on falling SCK; mode 3 (CPOL=1, CPHA=0) uses inverted clock polarity while retaining same sampling edge. Both modes support up to 66MHz operation with appropriate signal integrity.
How does the dual-buffer architecture of the AT45DB321D-SU-SL955 improve system performance?
The AT45DB321D-SU-SL955's two independent 512/528-byte SRAM buffers allow the host MCU to stream new data into one buffer while the other buffer's contents are being written to flash - eliminating wait states and enabling uninterrupted data acquisition. This concurrency reduces effective write latency by up to 50% compared to single-buffer flash devices and simplifies real-time firmware update logic.
Can the AT45DB321D-SU-SL955 be used as a direct replacement for standard SPI NOR flash?
The AT45DB321D-SU-SL955 is not a pin- or command-compatible drop-in replacement for standard SPI NOR flash due to its sequential-access architecture, dual-buffer commands, and page-oriented addressing. While it shares the same 8-pin SOIC footprint and basic SPI signals (CS/SCK/SI/SO), firmware must be adapted to use DataFlash-specific opcodes and buffer management - especially for erase, program, and continuous read operations.
What security mechanisms does the AT45DB321D-SU-SL955 provide for firmware protection?
The AT45DB321D-SU-SL955 provides layered security: hardware write protection via the WP pin (active-low, overrides software locks), programmable sector protection register, sector lockdown to permanently disable modification of protected regions, and a 128-byte security register containing 64 bytes of user-programmable space plus a factory-programmed 64-byte unique device identifier for cryptographic binding.
AT45DB321D-SU-SL955 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 8-SOIC (0.209", 5.30mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- FLASH
- Technology:
- FLASH
- Memory Size:
- 32Mbit
- Memory Organization:
- 512 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-SL955 FAQ
1.How can I place an order for AT45DB321D-SU-SL955 through Aetrix?
Please submit a Request for Quotation (RFQ) for AT45DB321D-SU-SL955 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-SL955 reliable?
The price and inventory of AT45DB321D-SU-SL955 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-SL955 is usually 5 days.
3.What payment methods are accepted for AT45DB321D-SU-SL955?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT45DB321D-SU-SL955 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT45DB321D-SU-SL955?
AT45DB321D-SU-SL955 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT45DB321D-SU-SL955 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-SL955?
For technical support, including AT45DB321D-SU-SL955 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT45DB321D-SU-SL955 requirements.
6.How does Aetrix verify that AT45DB321D-SU-SL955 is sourced from the original manufacturer or authorized distributors?
All AT45DB321D-SU-SL955 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-SL955 meets industry standards.
7.What is the process for return or replacement of AT45DB321D-SU-SL955?
All AT45DB321D-SU-SL955 units undergo pre-shipment inspection (PSI). If there is an issue with AT45DB321D-SU-SL955, 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-SL955 part is unused and in its original packaging.
Return procedure for AT45DB321D-SU-SL955:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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