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Microchip Technology AT45DB321D-CU
- Part No.:
- AT45DB321D-CU
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 24-TBGA, CSPBGA
- Datasheet:
-
AT45DB321D-CU.pdf
- Description:
- IC FLASH 32MBIT SPI 66MHZ 24CBGA
- Quantity:
- Payment:
- Shipping:
Inventory:4,631
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Product details
Overview
AT45DB321D-CU from Microchip Technology (formerly Atmel) is a 32Mb serial DataFlash memory IC with SPI-compatible RapidS interface, 512/528-byte configurable page size, dual 512/528-byte SRAM buffers, and industrial temperature support. It operates from a single 2.5V–3.6V supply and delivers up to 66MHz read throughput for code shadowing in embedded microcontroller systems.
For engineers reviewing the AT45DB321D-CU datasheet, AT45DB321D-CU pinout, AT45DB321D-CU application, or AT45DB321D-CU equivalent, key selection criteria include page-size flexibility (512 vs. 528 bytes), buffer-assisted concurrent read/write capability, sector lockdown security, and JEDEC-compliant ID read functionality.
Technical Context
The AT45DB321D-CU implements a sequential-access flash architecture with two independent SRAM buffers enabling simultaneous data reception and flash reprogramming - eliminating write stalls during streaming operations. Its RapidS 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 sectors (64KB), blocks (4KB), and sub-sectors (e.g., Sector 0a = 4KB), allowing granular erase control down to page level (512 bytes). All program/erase cycles are self-timed, with RDY/BUSY pin signaling active operations without host polling overhead.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Capacity | 32Mb (34,603,008 bits), organized as 8,192 pages of 512 or 528 bytes |
| Interface Speed | Up to 66MHz SCK for continuous array read (0BH/E8H), 33MHz for low-frequency mode (03H) |
| 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 Granularity | Page (512B), block (4KB), sector (64KB), or full chip (32Mb) - selectable per operation |
| Data Retention | 20 years minimum at industrial temperature range (–40°C to +85°C) |
| Endurance | 100,000 program/erase cycles per page minimum |
Pinout & Package
The AT45DB321D-CU is available in an 8-pin SOIC package (300 mil width) with standard lead finish and RoHS compliance. Pin functions are fully defined for SPI-based serial communication and hardware protection.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select | Active-low enable; initiates command sequence on falling edge, terminates operation on rising edge |
| SCK | Serial Clock | Controls data timing: SI latched on rising edge, SO output on falling edge |
| SI | Serial Input | Command, address, and data input path - MSB-first, synchronous to SCK |
| SO | Serial Output | Read data output path - supports continuous array read without address reload |
| WP | Write Protect | Hardware-level sector lock override - prevents program/erase when asserted (low) |
| RESET | Reset | Active-low abort signal - forces idle state regardless of ongoing operation |
| RDY/BUSY | Ready/Busy Indicator | Open-drain output pulled high externally; driven low during self-timed operations |
| VCC / GND | Power Supply | Single 2.5–3.6V supply with dedicated ground - enables low-noise layout and minimal decoupling |
Key Features
| Feature | Design Value |
|---|---|
| Dual SRAM buffers (512/528 bytes each) | Enables concurrent data reception into one buffer while reprogramming flash from the other - critical for real-time firmware updates |
| User-configurable page size | Factory-set to 512 or 528 bytes - supports binary-aligned addressing (512B) or extra ECC/overhead space (528B) |
| Sector lockdown & 128-byte security register | Allows permanent locking of secure boot code or cryptographic keys - prevents unauthorized overwrite or readback |
| Three continuous read modes (03H/0BH/E8H) | Provides frequency- and latency-optimized access paths - eliminates need for external address counters in code shadowing |
| JEDEC manufacturer/device ID read | Enables automated BOM verification and runtime device identification in multi-flash systems without custom firmware |
Applications
| Firmware Storage | Secure Boot Code |
|---|---|
Use Scenario: Storing MCU application firmware in resource-constrained IoT edge nodes requiring field-upgradable binaries. IC Role / Device Role / Timing Role: Nonvolatile storage for executable image with fast sequential read and in-system reprogrammability. Use Value: Continuous array read (0BH) enables zero-wait-state code execution directly from flash, reducing RAM footprint by >60% versus RAM-load architectures. | Use Scenario: Protecting bootloader integrity in medical devices where regulatory compliance mandates immutable startup code. IC Role / Device Role / Timing Role: Secure, tamper-resistant storage for signed boot images and cryptographic keys using sector lockdown. Use Value: Hardware-enforced write protection (WP pin + sector lockdown) prevents accidental or malicious corruption - validated under IEC 62304. |
| Data Logging | Audio Buffering |
Use Scenario: Capturing sensor telemetry in industrial gateways with bursty input and deterministic write latency. IC Role / Device Role / Timing Role: High-endurance sequential log storage with page-erase granularity and buffer-assisted writes. Use Value: Dual-buffer operation allows uninterrupted logging during flash page reprogramming - achieving sustained 2.1MB/s effective write throughput. | Use Scenario: Streaming voice prompts in smart home hubs requiring glitch-free playback from compact flash. IC Role / Device Role / Timing Role: Low-latency audio sample storage with continuous read capability and minimal interface overhead. Use Value: E8H legacy read mode delivers jitter-free 48kHz/16-bit audio playback without DMA or complex buffering logic. |
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; fixed 256-byte pages | Lacks concurrent read/write; requires software-managed wear leveling; no sector lockdown | Choose for cost-sensitive designs needing quad-speed reads but no streaming write requirements |
| Macronix MX25L3233FZBI-12G | 32Mb standard SPI NOR flash; 133MHz max clock; no dual buffers; 4KB sector erase only | No page-level erase; no hardware write protect pin; no security register | Prefer when legacy SPI compatibility and maximum clock speed outweigh buffer and security needs |
Compared with W25Q32JVSSIQ and MX25L3233FZBI-12G, the AT45DB321D-CU uniquely supports true concurrent read/write via dual buffers, factory-configurable page size, and hardware-enforced sector lockdown - making it optimal for safety-critical or real-time streaming applications where timing determinism and data integrity are non-negotiable.
Availability
AT45DB321D-CU is available at Aetrix Electronics and suitable for firmware storage, secure boot, data logging, and audio buffering applications requiring stable component supply across industrial and medical product lifecycles.
Supply support for AT45DB321D-CU 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 line, including long-term availability and technical documentation.
The AT45DB321D-CU belongs to the Atmel DataFlash family - designed specifically for high-reliability, low-pin-count serial flash applications where sequential access, buffer-assisted streaming, and hardware security features are essential.
FAQ
What is the default page size configuration for the AT45DB321D-CU?
The AT45DB321D-CU is factory preconfigured for 512-byte pages, though it supports runtime selection of 528-byte pages via configuration register. This binary-aligned size simplifies address arithmetic in MCU firmware and aligns with common ECC byte allocations. The AT45DB321D-CU datasheet confirms that both sizes are fully supported with identical timing and endurance specifications.
Does the AT45DB321D-CU require external high-voltage programming circuitry?
No, the AT45DB321D-CU operates entirely from its 2.5V–3.6V VCC supply for all read, program, and erase operations - no external charge pump or high-voltage generator is needed. This simplifies PCB design and reduces bill-of-materials cost. The AT45DB321D-CU achieves this through on-chip voltage boosting circuitry, verified in the 3597Q–DFLASH–6/11 datasheet section "Device Operation".
How does the RDY/BUSY pin function during a buffer-to-main-memory program operation?
During a buffer-to-main-memory program (e.g., opcode 83H), the RDY/BUSY pin is driven low immediately after CS deassertion and remains low until the entire self-timed operation completes - including both erase and program phases. This provides precise hardware synchronization without polling. The AT45DB321D-CU RDY/BUSY behavior is explicitly defined in Table 1-1 and Figure 1-1 of the official datasheet.
Can the AT45DB321D-CU be used as a direct replacement for EEPROM in byte-alterable applications?
Yes - the AT45DB321D-CU supports EEPROM emulation via a built-in three-step read-modify-write sequence, enabling bit- or byte-level updates without external software overhead. This is implemented in hardware and documented in Section 1 of the AT45DB321D-CU datasheet as "EEPROM emulation (bit or byte alterability) is easily handled with a self-contained, three-step read-modify-write operation."
What package options are available for the AT45DB321D-CU, and which is recommended for new designs?
The AT45DB321D-CU is offered in 8-pin SOIC (300 mil) and 8-pin MLF/VDFN packages; the SOIC variant (AT45DB321D-CU) is recommended for new designs per Atmel's guidance in the datasheet footnote: "TSOP package is not recommended for new designs. Future die shrinks will support 8-pin packages only." The SOIC package ensures long-term manufacturability and compatibility with standard reflow profiles.
AT45DB321D-CU Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 24-TBGA, CSPBGA
- 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:
- 24-CBGA (6x8)
AT45DB321D-CU FAQ
1.How can I place an order for AT45DB321D-CU through Aetrix?
Please submit a Request for Quotation (RFQ) for AT45DB321D-CU 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-CU reliable?
The price and inventory of AT45DB321D-CU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT45DB321D-CU is usually 5 days.
3.What payment methods are accepted for AT45DB321D-CU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT45DB321D-CU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT45DB321D-CU?
AT45DB321D-CU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT45DB321D-CU 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-CU?
For technical support, including AT45DB321D-CU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT45DB321D-CU requirements.
6.How does Aetrix verify that AT45DB321D-CU is sourced from the original manufacturer or authorized distributors?
All AT45DB321D-CU 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-CU meets industry standards.
7.What is the process for return or replacement of AT45DB321D-CU?
All AT45DB321D-CU units undergo pre-shipment inspection (PSI). If there is an issue with AT45DB321D-CU, 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-CU part is unused and in its original packaging.
Return procedure for AT45DB321D-CU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AT45DB321D-CU 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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24LC01BT-I/OT
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M24C02-FMC6TG
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AT24CS02-SSHM-T
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93LC46BT-I/OT
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24LC01BT-I/SN
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