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Microchip Technology AT45DB321C-RC
- Part No.:
- AT45DB321C-RC
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 28-SOIC (0.342", 8.69mm Width)
- Datasheet:
-
AT45DB321C-RC.pdf
- Description:
- IC FLASH 32MBIT SPI 40MHZ 28SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,674
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Product details
Overview
AT45DB321C from Microchip Technology is a 33-Mbit (8192 × 528-byte pages) SPI-compatible serial Flash memory with RapidS™ interface, dual 528-byte SRAM buffers, hardware/software sector protection, and 100,000 program/erase cycles per page - used for code shadowing, firmware storage, and embedded data logging in industrial controllers and audio systems.
For engineers reviewing the AT45DB321C datasheet, AT45DB321C pinout, AT45DB321C application, or AT45DB321C equivalent, key selection considerations include its 40 MHz max clock frequency, continuous array read capability, buffer-assisted concurrent write/read operation, and JEDEC-standard manufacturer/device ID support.
Technical Context
The AT45DB321C implements a serial RapidS interface compatible with SPI Modes 0 and 3 up to 33 MHz, using CS/SCK/SI/SO signals plus RDY/BUSY, RESET, and WP control lines. Its architecture separates 33-Mbit main Flash memory (organized as 8192 pages of 528 bytes) from two independent 528-byte SRAM buffers, enabling simultaneous data reception and Flash reprogramming.
Page-level and block-level (8-page) erase operations are self-timed and supported by status register bit 7 (RDY/BUSY) and RDY/BUSY pin assertion. Sector protection is implemented via a nonvolatile 16-byte register with hardware (WP pin) and software command-based enable/disable control, and includes a 128-byte security register with 64-byte user-programmable space and unique 64-byte device identifier.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Density | 33,554,432 bits (8192 pages × 528 bytes), enabling compact firmware image storage without parallel bus overhead |
| Interface Speed | Up to 40 MHz clock (33 MHz for SPI Modes 0/3), supporting high-throughput firmware updates and real-time audio streaming |
| Supply Voltage | 2.7–3.6 V single supply, compatible with 3.3 V logic systems and eliminating need for level shifters |
| Active Read Current | 10 mA typical, minimizing power draw during boot-time code shadowing or configuration loading |
| Data Retention | 20 years minimum, ensuring long-term reliability in unattended industrial monitoring devices |
| Endurance | 100,000 program/erase cycles per page, supporting frequent field-upgrade scenarios in IoT edge nodes |
| Operating Temp | −40°C to +85°C industrial range, validated for use in automotive infotainment head units and factory automation PLCs |
Pinout & Package
AT45DB321C is available in multiple RoHS-compliant packages including 28-pin SOIC, 28-pin TSOP, 24-ball CBGA, and 8-pin CASON - all sharing identical pin function mapping and electrical behavior.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select | Active-low enable signal; must remain low during full instruction sequence (opcode + address + data) |
| SCK | Serial Clock | Master-generated clock up to 40 MHz; controls timing of SI input and SO output bit transfers |
| SI | Serial Input | Input-only data line for opcodes, addresses, and buffer write data; MSB-first protocol |
| SO | Serial Output | Output-only data line for read data and status register; tristated on CS high |
| WP | Hardware Write Protect | Active-low pin that locks protected sectors from program/erase when asserted; includes internal noise filter |
| RESET | Chip Reset | Active-low asynchronous reset; clears internal state but does not affect software sector protection settings |
| RDY/BUSY | Ready/Busy Indicator | Open-drain output reflecting status register bit 7; low = busy during erase/program/transfer operations |
| VCC / GND | Power Supply | Single 2.7–3.6 V supply; decoupling capacitor required near VCC pin for stable high-speed operation |
Key Features
| Feature | Design Value |
|---|---|
| Dual SRAM Buffers | Two independent 528-byte buffers allow background Flash programming while receiving new data - essential for seamless firmware OTA updates |
| Continuous Array Read | Single opcode (E8h) enables uninterrupted sequential read across page boundaries with no latency penalty - ideal for boot ROM shadowing |
| Automated Erase | Self-timed page (528 B) and block (4224 B) erase eliminates external timing circuitry and simplifies host driver development |
| Security Register | 128-byte dedicated register with 64-byte user space and unique 64-byte device ID supports secure firmware binding and anti-cloning |
| JEDEC ID Support | Standard manufacturer (1Fh) and device (26h) ID read commands enable automatic part identification in multi-vendor BOM environments |
Applications
| Audio Voice Recording | Firmware Storage |
|---|---|
Use Scenario: Embedded voice recorder in industrial safety intercoms capturing alarm announcements and operator instructions. IC Role / Device Role / Timing Role: Nonvolatile storage for compressed audio samples with fast sequential read access and low-power standby. Use Value: Continuous array read mode delivers gapless playback; 6 µA standby current extends battery life in portable units. | Use Scenario: Storing boot firmware and configuration parameters in programmable logic controllers (PLCs) deployed in factory automation. IC Role / Device Role / Timing Role: SPI-connected code storage device supporting in-system reprogramming without high-voltage programming signals. Use Value: Dual-buffer architecture allows firmware update while maintaining runtime execution from alternate memory region. |
| Data Logging | Secure Configuration Storage |
Use Scenario: Environmental sensor node recording temperature/humidity readings at 10-second intervals over 6-month deployments. IC Role / Device Role / Timing Role: High-endurance Flash memory managing cyclic write/erase of timestamped records with wear leveling handled by host MCU. Use Value: 100,000 program/erase cycles per page ensures >15-year operational lifetime under specified logging duty cycle. | Use Scenario: Medical diagnostic equipment storing calibration coefficients, user preferences, and regulatory compliance flags. IC Role / Device Role / Timing Role: Secure nonvolatile storage with hardware write protection and encrypted sector locking to prevent unauthorized parameter modification. Use Value: 128-byte security register with unique device ID enables cryptographic binding of calibration data to specific hardware unit. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial Flash memory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT45DB321D | Successor with enhanced reliability, same pinout and command set; supports higher endurance (200K cycles) and extended temperature range (−40°C to +105°C) | Preferred for new designs requiring longer lifecycle or extended thermal operation; backward-compatible replacement | Select AT45DB321D for production ramp; AT45DB321C remains viable for legacy repair and inventory reuse |
| W25Q32JVSSIQ | 32-Mbit Quad SPI Flash with faster 104 MHz DTR read, but lacks dual buffers and continuous array read; requires different command set and driver adaptation | Better suited for high-speed code XIP applications; unsuitable for buffer-concurrent write/read workflows | Choose only if system already uses Winbond Quad SPI ecosystem and does not rely on DataFlash-specific features like auto-erase-on-program |
Compared with AT45DB321D, the AT45DB321C offers identical functionality at lower cost for existing designs, while W25Q32JVSSIQ trades buffer concurrency and continuous read simplicity for raw bandwidth - making AT45DB321C optimal where deterministic latency and host-software simplicity are prioritized over peak throughput.
Availability
AT45DB321C is available at Aetrix Electronics and suitable for industrial control systems, medical instrumentation, and audio recording modules requiring stable component supply and long-term obsolescence management.
Supply support for AT45DB321C 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 is a U.S.-based semiconductor company specializing in microcontrollers, analog components, and nonvolatile memory solutions for industrial, automotive, and communications markets.
The AT45DB321C belongs to Microchip's DataFlash® family - designed specifically to replace parallel EEPROM/Flash in space-constrained embedded systems by delivering high-density serial storage with integrated SRAM buffers and simplified command protocols.
FAQ
What is the maximum clock frequency supported by the AT45DB321C for SPI Mode 0 operation?
The AT45DB321C supports up to 33 MHz for SPI Modes 0 and 3, and up to 40 MHz for its proprietary RapidS™ interface. For standard SPI Mode 0 compatibility, the maximum guaranteed clock frequency is 33 MHz - verified in the official datasheet (3387M–DFLASH–2/08, Section 1). Exceeding this may cause timing violations during opcode/address latching.
Does the AT45DB321C require external high-voltage programming signals?
No, the AT45DB321C operates from a single 2.7–3.6 V supply for both read and program/erase operations. It contains internal charge pumps and does not require external VPP or elevated voltages - a key design advantage over legacy parallel Flash devices. This simplifies power design and eliminates need for additional voltage regulators or level shifters in the AT45DB321C system implementation.
How does the dual-buffer architecture of the AT45DB321C improve system performance?
The AT45DB321C's two independent 528-byte SRAM buffers enable true concurrent operation: while one buffer receives incoming data via SI, the other can simultaneously program its contents into Flash memory. This eliminates idle time during firmware updates or data logging, reducing effective write latency by up to 50% compared to single-buffer serial Flash devices - directly improving responsiveness in real-time AT45DB321C-based systems.
Can the AT45DB321C be used for code execution directly from memory (XIP)?
The AT45DB321C supports continuous array read mode (opcode E8h), which enables gapless sequential access ideal for code shadowing - copying firmware into RAM at boot. However, it does not support true execute-in-place (XIP) due to lack of random-access addressing and variable-latency erase/program cycles. Systems requiring XIP should consider Quad SPI Flash alternatives, whereas AT45DB321C excels in buffered load-and-run architectures.
What is the purpose of the RDY/BUSY pin on the AT45DB321C?
The RDY/BUSY pin on the AT45DB321C provides hardware-level status feedback synchronized with status register bit 7. It asserts low during all self-timed operations - including page/block erase, buffer-to-Flash programming, and main memory-to-buffer transfer - allowing the host MCU to poll asynchronously without consuming CPU cycles on SPI status reads. This improves deterministic timing control in AT45DB321C-based real-time applications.
AT45DB321C-RC Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 28-SOIC (0.342", 8.69mm Width)
- Packaging:
- Tube
- 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:
- 40 MHz
- Write Cycle Time - Word, Page:
- 15ms
- Access Time:
- -
- Voltage - Supply:
- 2.7V ~ 3.6V
- Operating Temperature:
- 0°C ~ 70°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 28-SOIC
AT45DB321C-RC FAQ
1.How can I place an order for AT45DB321C-RC through Aetrix?
Please submit a Request for Quotation (RFQ) for AT45DB321C-RC 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 AT45DB321C-RC reliable?
The price and inventory of AT45DB321C-RC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT45DB321C-RC is usually 5 days.
3.What payment methods are accepted for AT45DB321C-RC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT45DB321C-RC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT45DB321C-RC?
AT45DB321C-RC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT45DB321C-RC 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 AT45DB321C-RC?
For technical support, including AT45DB321C-RC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT45DB321C-RC requirements.
6.How does Aetrix verify that AT45DB321C-RC is sourced from the original manufacturer or authorized distributors?
All AT45DB321C-RC 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 AT45DB321C-RC meets industry standards.
7.What is the process for return or replacement of AT45DB321C-RC?
All AT45DB321C-RC units undergo pre-shipment inspection (PSI). If there is an issue with AT45DB321C-RC, 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 AT45DB321C-RC part is unused and in its original packaging.
Return procedure for AT45DB321C-RC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AT45DB321C-RC Tags
-
M24C02-WMN6TP
STMicroelectronics
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AT24C02C-XHM-T
Microchip Technology
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AT21CS01-STUM10-T
Microchip Technology
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AT24C02C-SSHM-T
Microchip Technology
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24LC01BT-I/OT
Microchip Technology
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M24C02-FMC6TG
STMicroelectronics
-
AT24CS02-SSHM-T
Microchip Technology
-
93LC46BT-I/OT
Microchip Technology
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AT24C04C-SSHM-T
Microchip Technology
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24LC01BT-I/SN
Microchip Technology
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24AA02UIDT-I/OT
Microchip Technology
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AT24C08C-STUM-T
Microchip Technology
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