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Microchip Technology AT45DB321C-CNC
- Part No.:
- AT45DB321C-CNC
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-VDFN
- Datasheet:
-
AT45DB321C-CNC.pdf
- Description:
- IC FLASH 32MBIT SPI 40MHZ 8CASON
- Quantity:
- Payment:
- Shipping:
Inventory:3,133
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Product details
Overview
AT45DB321C-CNC from Microchip Technology is a 32-Mbit SPI-compatible serial Flash memory with RapidS™ interface, organized as 8192 pages × 528 bytes, featuring dual 528-byte SRAM buffers and hardware/software sector protection. It operates from a single 2.7–3.6V supply, supports up to 40 MHz clock (33 MHz in SPI Modes 0/3), and delivers 10 mA typical active read current - ideal for embedded code shadowing and firmware storage in space-constrained industrial controllers.
For engineers reviewing the AT45DB321C-CNC datasheet, AT45DB321C-CNC pinout, AT45DB321C-CNC application, or AT45DB321C-CNC equivalent, key selection criteria include page-erase granularity (528 B), continuous array read capability, built-in buffer-to-flash program with auto-erase, 100,000 P/E cycles per page, and JEDEC-compliant manufacturer/device ID support.
Technical Context
The AT45DB321C-CNC implements a three-level memory architecture (sectors → blocks → pages), where each block spans 8 pages (4,224 bytes) and sectors vary in size (e.g., Sector 0a = 8 pages, Sector 0b = 504 pages). Its RapidS™ interface enables full-duplex command/data transfer using only CS, SCK, SI, and SO pins - eliminating address bus overhead and reducing PCB routing complexity.
Two independent 528-byte SRAM buffers enable concurrent data reception and flash reprogramming, supporting seamless EEPROM emulation via read-modify-write sequences. All erase and program operations are self-timed, with RDY/BUSY status reported via dedicated pin and status register bit 7.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Density | 32 Mbit (34,603,008 bits), organized as 8192 × 528-byte pages |
| Interface | RapidS™ serial (SPI Modes 0 & 3 compatible), 4-wire: CS/SCK/SI/SO |
| Max Clock Frequency | 40 MHz (RapidS mode); 33 MHz (standard SPI Mode 0/3) |
| Page Erase Time | tPE ≤ 25 ms - enables fast field firmware updates without full-chip erase |
| Data Retention | 20 years at 25°C - suitable for long-lifecycle industrial deployments |
| P/E Endurance | 100,000 program/erase cycles per page - supports frequent over-the-air update scenarios |
| Supply Voltage | 2.7 V to 3.6 V single supply - eliminates need for voltage translators in 3.3V systems |
| Standby Current | 6 µA typical - critical for battery-backed or low-power sensor node applications |
Pinout & Package
AT45DB321C-CNC is available in 28-pin SOIC (300 mil) package. Pin functions are defined per JEDEC MS-012 standard and validated across all supported packages (SOIC, TSOP, CBGA, CASON).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select | Active-low enable; initiates command sequence and holds device in selected state during SPI transaction |
| SCK | Serial Clock | Master-generated clock synchronizing all SI/SO data transfers; supports up to 40 MHz operation |
| SI | Serial Input | Command opcode, address, and data input path; MSB-first protocol with no byte alignment constraints |
| SO | Serial Output | Read data, status register, or device ID output; tri-stated on CS high transition |
| WP | Hardware Write Protect | Active-low pin enabling permanent sector lockout independent of software commands; includes 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 real-time device status; low = busy (erase/program/transfer in progress) |
| VCC / GND | Power Supply | Single 2.7–3.6V supply; decoupling required within 10 mm of pins per layout guidelines |
Key Features
| Feature | Design Value |
|---|---|
| Dual SRAM Buffers | Two independent 528-byte buffers enable simultaneous data streaming into one buffer while programming the other to flash - eliminates host wait states during firmware updates |
| Continuous Array Read | Opcode E8H enables uninterrupted sequential read across page boundaries with automatic address wrap - essential for boot code shadowing without CPU intervention |
| Buffer-to-Flash Program with Auto-Erase | Single-command (83H/86H) page write erases target page before programming - removes external erase scheduling logic from host firmware |
| Hardware + Software Sector Protection | WP pin provides persistent lock; Sector Protection Register allows selective 0a/0b/1–15 sector locking via 4-byte command sequences - meets IEC 62443 secure boot requirements |
| Security Register | 128-byte nonvolatile register with 64-byte user-programmable space and unique 64-byte device ID - supports secure provisioning and anti-cloning in certified devices |
| JEDEC ID Support | Standard Manufacturer ID (1Fh) and Device ID (26h) readable via SPI - enables automated BOM verification and supply-chain traceability |
Applications
| Firmware Storage | Code Shadowing |
|---|---|
|
Use Scenario: Storing bootloader and application firmware in industrial PLCs requiring field-upgradable code without external programming hardware. IC Role / Device Role / Timing Role: Nonvolatile program memory accessed via SPI during cold start and OTA updates; RDY/BUSY pin coordinates timing with host MCU. Use Value: 100,000 P/E cycles and 20-year retention ensure >10 years of reliable firmware revision management in unattended deployments. |
Use Scenario: Copying executable code from serial flash to RAM at system boot in resource-constrained microcontrollers (e.g., ARM Cortex-M0+). IC Role / Device Role / Timing Role: High-speed continuous read source (E8H command) delivering sequential instruction stream directly to CPU prefetch buffer. Use Value: 40 MHz RapidS™ interface and zero-latency page-boundary crossing reduce boot time by ≥35% vs. parallel NOR flash alternatives. |
| Secure Data Logging | EEPROM Emulation |
|
Use Scenario: Tamper-resistant event logging in medical diagnostic equipment where audit trail integrity must survive power loss and physical inspection. IC Role / Device Role / Timing Role: Protected storage for timestamped records using hardware WP pin and sector-locked security register for cryptographic keys. Use Value: Unique 64-byte device ID and 64-byte user space enable cryptographically bound log entries - satisfies FDA 21 CFR Part 11 electronic record requirements. |
Use Scenario: Replacing discrete EEPROM in automotive body control modules needing byte-alterable parameter storage (e.g., calibration offsets, seat position memory). IC Role / Device Role / Timing Role: Self-contained read-modify-write engine using dual buffers to emulate random-access writes without host-side wear leveling. Use Value: Built-in three-step R-M-W operation reduces MCU firmware overhead by 70% and extends effective endurance beyond 1M write cycles via dynamic page rotation. |
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-CNU | Successor with enhanced reliability: 100K P/E cycles guaranteed across full temp range (-40°C to +85°C), improved tEP spec (≤20 ms), and updated JEDEC ID (27h) | Required for new designs per Microchip's "For New Designs Use" notice; identical pinout and command set | Select AT45DB321D-CNU for production ramps starting Q3 2024; AT45DB321C-CNC remains valid for legacy repair and obsolescence mitigation |
| W25Q32JVSSIQ | 32 Mbit Quad SPI flash (Winbond); supports x4 I/O mode (up to 80 MHz), lacks dual buffers and continuous array read; different command set (SFDP compliant) | Better raw throughput in x4 mode but requires host driver rewrite; no native EEPROM emulation capability | Choose W25Q32JVSSIQ only when migrating to Quad SPI infrastructure and accepting firmware rework; not drop-in compatible |
Compared with AT45DB321D-CNU, the AT45DB321C-CNC offers identical functionality but with slightly relaxed P/E cycle guarantee (100K min vs. 100K guaranteed) and older JEDEC ID; versus W25Q32JVSSIQ, it provides superior embedded-system usability via dual-buffer concurrency and continuous read - at the cost of lower peak bandwidth and no Quad SPI support.
Availability
AT45DB321C-CNC is available at Aetrix Electronics and suitable for industrial control firmware storage, medical device code shadowing, and secure data logging requiring stable component supply across extended product lifecycles.
Supply support for AT45DB321C-CNC 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, with ISO 9001-certified manufacturing and global distribution.
The AT45DB321C-CNC belongs to Microchip's DataFlash® family - engineered specifically for embedded systems needing high-density serial flash with integrated SRAM buffers and robust data integrity features for code and parameter storage.
FAQ
What is the maximum clock frequency supported by the AT45DB321C-CNC in standard SPI mode?
The AT45DB321C-CNC supports up to 33 MHz in standard SPI Modes 0 and 3, as confirmed in its RapidS™ interface specification. While the device accepts clocks up to 40 MHz in proprietary RapidS™ mode, SPI-compliant hosts must limit SCK to 33 MHz to ensure timing compliance with setup/hold requirements for opcode and address latching.
Does the AT45DB321C-CNC require high-voltage programming signals?
No, the AT45DB321C-CNC operates entirely from a single 2.7–3.6V supply for both read and program/erase operations. It eliminates the need for external 12V programming voltages or charge pumps - simplifying power design and enabling direct connection to 3.3V MCU I/O without level shifters.
How does the AT45DB321C-CNC handle page boundary crossing during continuous read?
During Continuous Array Read (opcode E8H), the AT45DB321C-CNC automatically increments its internal address counter across page boundaries with zero delay - reading byte 527 of Page N followed immediately by byte 0 of Page N+1. This behavior is hardware-implemented and requires no host intervention or additional addressing.
Can the AT45DB321C-CNC be used for true byte-level writes like EEPROM?
The AT45DB321C-CNC does not support true byte-level writes, but enables EEPROM emulation via its dual-buffer architecture and self-contained read-modify-write command sequence (Main Memory Page to Buffer Transfer + Buffer Write + Buffer to Main Memory Page Program). This achieves functional equivalence with deterministic latency and no external wear-leveling logic.
What is the purpose of the RDY/BUSY pin on the AT45DB321C-CNC?
The RDY/BUSY pin on the AT45DB321C-CNC provides hardware-level status signaling: it asserts low during any self-timed operation (page erase, buffer-to-flash program, main memory transfer) and returns high when ready for the next command. This eliminates polling overhead and ensures deterministic timing for time-critical host firmware.
AT45DB321C-CNC Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-VDFN
- 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:
- 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:
- 8-CASON (6x8)
AT45DB321C-CNC FAQ
1.How can I place an order for AT45DB321C-CNC through Aetrix?
Please submit a Request for Quotation (RFQ) for AT45DB321C-CNC 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-CNC reliable?
The price and inventory of AT45DB321C-CNC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT45DB321C-CNC is usually 5 days.
3.What payment methods are accepted for AT45DB321C-CNC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT45DB321C-CNC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT45DB321C-CNC?
AT45DB321C-CNC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT45DB321C-CNC 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-CNC?
For technical support, including AT45DB321C-CNC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT45DB321C-CNC requirements.
6.How does Aetrix verify that AT45DB321C-CNC is sourced from the original manufacturer or authorized distributors?
All AT45DB321C-CNC 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-CNC meets industry standards.
7.What is the process for return or replacement of AT45DB321C-CNC?
All AT45DB321C-CNC units undergo pre-shipment inspection (PSI). If there is an issue with AT45DB321C-CNC, 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-CNC part is unused and in its original packaging.
Return procedure for AT45DB321C-CNC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AT45DB321C-CNC 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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AT24C04C-SSHM-T
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24LC01BT-I/SN
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24AA02UIDT-I/OT
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AT24C08C-STUM-T
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