My Inquiry
My Account
Microchip Technology AT45DB321C-CNU
- Part No.:
- AT45DB321C-CNU
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-VDFN
- Datasheet:
-
AT45DB321C-CNU.pdf
- Description:
- IC FLASH 32MBIT SPI 40MHZ 8CASON
- Quantity:
- Payment:
- Shipping:
Inventory:3,705
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
AT45DB321C-CNU from Microchip Technology is a 32-Mbit SPI-compatible serial Flash memory with RapidS™ interface, organized as 8192 pages × 528 bytes (33,554,432 bits), supporting continuous array read for code shadowing, dual 528-byte SRAM buffers for concurrent data reception and reprogramming, and hardware/software sector protection. It operates from a single 2.7–3.6 V supply with 10 mA typical active read current and 6 µA standby current.
For engineers reviewing the AT45DB321C-CNU datasheet, AT45DB321C-CNU pinout, AT45DB321C-CNU application, or AT45DB321C-CNU equivalent, key selection considerations include its 40 MHz max clock frequency (SPI Modes 0/3 up to 33 MHz), page/block erase granularity, 100,000 program/erase cycles per page, 20-year data retention, and JEDEC-compliant manufacturer/device ID support.
Technical Context
The AT45DB321C-CNU implements a serial Flash architecture with hierarchical memory organization: 16 sectors (Sector 0a/b + Sectors 1–15), each containing blocks of 8 pages (4,224 bytes), and individual pages of 528 bytes (512 data + 16 overhead). Its RapidS™ interface enables high-speed sequential access without address lines, reducing pin count and layout complexity.
It supports three distinct programming workflows: buffer-to-memory with built-in erase (opcode 83H/86H), buffer-to-memory without erase (88H/89H), and combined buffer write + program (82H/85H). Status register bit 7 provides real-time RDY/BUSY indication, while bit 6 reports main memory–buffer compare results, and bit 1 reflects sector protection state.
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 interface compatible with SPI Modes 0 and 3; max 40 MHz clock, 33 MHz guaranteed |
| Supply Voltage | Single 2.7–3.6 V rail - eliminates need for charge pumps or dual supplies |
| Erase Granularity | Page erase (528 B) or block erase (4,224 B = 8 pages); no chip-erase command |
| Data Retention | 20 years at 85°C - validated for industrial temperature range operation |
| Endurance | 100,000 program/erase cycles per page - enables robust firmware update logging |
| Power Consumption | 10 mA typical active read current; 6 µA typical standby - suitable for battery-backed systems |
Pinout & Package
AT45DB321C-CNU is packaged in a 28-pin SOIC (Small Outline Integrated Circuit) with 300 mil body width, RoHS-compliant and halide-free. Pin functions are electrically defined and validated per Microchip's official datasheet (3387M–DFLASH–2/08).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select | Active-low enable; initiates command sequence on falling edge and terminates operations on rising edge |
| SCK | Serial Clock | Input clock synchronizing all SI/SO data transfers; supports up to 40 MHz |
| SI | Serial Input | Command, address, and data input path (MSB-first); used for opcodes, addresses, and buffer writes |
| SO | Serial Output | Command response, status register, and memory/buffer data output path |
| WP | Hardware Write Protect | Active-low pin enabling permanent sector lockout independent of software commands |
| RESET | Chip Reset | Active-low asynchronous reset; clears internal state but does not affect sector protection settings |
| RDY/BUSY | Ready/Busy Indicator | Open-drain output reflecting internal operation status; low = busy (erase/program/transfer) |
| VCC / GND | Power Supply | Single 2.7–3.6 V supply and ground - no auxiliary voltage rails required |
Key Features
| Feature | Design Value |
|---|---|
| Dual 528-byte SRAM buffers | Enable simultaneous data streaming into one buffer while reprogramming flash from the other - critical for zero-latency firmware updates |
| Continuous Array Read (CAR) | Supports seamless code shadowing across page boundaries with no delay or address reload - ideal for XIP boot loaders |
| Individual sector locking | Hardware (WP pin) and software-controlled protection of 16 sectors - prevents accidental overwrite of bootloader or calibration data |
| 128-byte security register | Contains 64-byte user-programmable space + 64-byte unique device identifier - enables secure device authentication and traceability |
| Self-timed erase/program | No external timing control needed; RDY/BUSY pin and status register bit 7 provide deterministic completion signaling |
Applications
| Embedded Bootloader Storage | Firmware Update Logging |
|---|---|
Use Scenario: Storing primary bootloader and configuration parameters in systems requiring fast, reliable cold-start execution. IC Role / Device Role / Timing Role: Nonvolatile storage for executable code with continuous array read capability enabling direct XIP (execute-in-place) from flash. Use Value: Eliminates need for external RAM-based code loading; 20-year data retention ensures integrity over product lifetime. |
Use Scenario: Recording version history, patch metadata, and rollback checkpoints during over-the-air (OTA) firmware updates. IC Role / Device Role / Timing Role: High-endurance log storage using page-level writes and sector-locked protected regions for immutable headers. Use Value: 100,000 program/erase cycles per page supports frequent field updates without premature wear-out. |
| Industrial HMI Display Buffer | Digital Voice/Image Data Archive |
Use Scenario: Caching UI assets (fonts, icons, bitmaps) in human-machine interface panels with limited PCB real estate. IC Role / Device Role / Timing Role: Serial Flash providing burst-read access to graphical assets via RapidS™ interface at up to 33 MHz. Use Value: Dual SRAM buffers allow background asset preloading while display controller reads from active buffer - no visual stutter. |
Use Scenario: Storing compressed voice prompts or sensor-captured images in portable medical or environmental monitoring devices. IC Role / Device Role / Timing Role: Low-power, high-density serial memory supporting intermittent capture and batch retrieval via SPI. Use Value: 6 µA standby current extends battery life; block erase minimizes time to clear large captured datasets. |
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 device with identical pinout, enhanced reliability, and extended 10-year minimum endurance guarantee; same 32-Mbit density and SOIC-28 package | Preferred for new designs requiring long-term supply assurance and updated qualification testing | Select AT45DB321D-CNU for new projects; AT45DB321C-CNU remains valid for legacy design continuity and cost-sensitive replacements |
| W25Q32JVSSIQ | 32-Mbit Quad SPI Flash with 4-line I/O mode (up to 80 MHz), no integrated SRAM buffers, different command set and sector protection model | Better suited for high-throughput data streaming where quad interface bandwidth outweighs buffer concurrency needs | Choose W25Q32JVSSIQ only when system firmware supports QSPI protocol and concurrent buffer operation is unnecessary |
Compared with AT45DB321D-CNU, the AT45DB321C-CNU offers proven field reliability but lacks the newer qualification and extended endurance warranty; compared with W25Q32JVSSIQ, it delivers unique dual-buffer concurrency and simpler SPI-only integration at the cost of lower peak bandwidth.
Availability
AT45DB321C-CNU is available at Aetrix Electronics and suitable for embedded bootloader storage, firmware update logging, and industrial HMI display buffering requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for AT45DB321C-CNU 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 global semiconductor company specializing in microcontrollers, analog components, and nonvolatile memory solutions, with a focus on embedded control and connectivity.
The AT45DB321C-CNU belongs to Microchip's DataFlash® family - designed specifically for systems needing high-speed serial Flash with integrated SRAM buffers to enable concurrent read/write operations in resource-constrained environments.
FAQ
What is the maximum clock frequency supported by the AT45DB321C-CNU?
The AT45DB321C-CNU supports a maximum clock frequency of 40 MHz for RapidS™ interface operation. However, full SPI Mode 0 and Mode 3 compatibility is guaranteed up to 33 MHz per the official datasheet (3387M–DFLASH–2/08). Exceeding 33 MHz may require validation under specific signal integrity conditions and is not recommended for production designs relying on standard SPI timing margins.
Does the AT45DB321C-CNU require high-voltage programming?
No, the AT45DB321C-CNU does not require high-voltage programming. It operates entirely from a single 2.7–3.6 V supply for both read and program/erase operations. All internal programming and erase cycles are self-timed and managed by on-chip circuitry - eliminating external voltage boosters or complex power sequencing.
How does the dual-buffer architecture of the AT45DB321C-CNU improve system performance?
The AT45DB321C-CNU's two independent 528-byte SRAM buffers enable true concurrency: while the host processor streams new data into one buffer via SI, the device simultaneously reprograms a flash page from the other buffer. This eliminates idle wait states during firmware updates or data logging, directly improving throughput and responsiveness in real-time embedded applications.
Can the AT45DB321C-CNU be used for code execution directly from flash (XIP)?
Yes, the AT45DB321C-CNU supports execute-in-place (XIP) via its Continuous Array Read (CAR) command (opcode E8H), which allows uninterrupted sequential read across page boundaries with no latency penalty. This makes it suitable for boot code storage and direct execution in microcontroller-based systems without intermediate RAM loading.
What is the purpose of the RDY/BUSY pin on the AT45DB321C-CNU?
The RDY/BUSY pin on the AT45DB321C-CNU is an open-drain output that goes low during any internal operation - including page/block erase, buffer-to-memory programming, main memory page transfer, and auto page rewrite. It provides hardware-level synchronization, allowing the host to poll without reading the status register, reducing SPI traffic and simplifying timing-critical firmware logic.
AT45DB321C-CNU 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:
- -40°C ~ 85°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-CASON (6x8)
AT45DB321C-CNU FAQ
1.How can I place an order for AT45DB321C-CNU through Aetrix?
Please submit a Request for Quotation (RFQ) for AT45DB321C-CNU 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-CNU reliable?
The price and inventory of AT45DB321C-CNU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT45DB321C-CNU is usually 5 days.
3.What payment methods are accepted for AT45DB321C-CNU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT45DB321C-CNU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT45DB321C-CNU?
AT45DB321C-CNU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT45DB321C-CNU 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-CNU?
For technical support, including AT45DB321C-CNU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT45DB321C-CNU requirements.
6.How does Aetrix verify that AT45DB321C-CNU is sourced from the original manufacturer or authorized distributors?
All AT45DB321C-CNU 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-CNU meets industry standards.
7.What is the process for return or replacement of AT45DB321C-CNU?
All AT45DB321C-CNU units undergo pre-shipment inspection (PSI). If there is an issue with AT45DB321C-CNU, 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-CNU part is unused and in its original packaging.
Return procedure for AT45DB321C-CNU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AT45DB321C-CNU Tags
-
M24C02-WMN6TP
STMicroelectronics
-
AT24C02C-XHM-T
Microchip Technology
-
AT21CS01-STUM10-T
Microchip Technology
-
AT24C02C-SSHM-T
Microchip Technology
-
24LC01BT-I/OT
Microchip Technology
-
M24C02-FMC6TG
STMicroelectronics
-
AT24CS02-SSHM-T
Microchip Technology
-
93LC46BT-I/OT
Microchip Technology
-
AT24C04C-SSHM-T
Microchip Technology
-
24LC01BT-I/SN
Microchip Technology
-
24AA02UIDT-I/OT
Microchip Technology
-
AT24C08C-STUM-T
Microchip Technology
Tech Hub
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
