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Microchip Technology AT45DB321B-TI
- Part No.:
- AT45DB321B-TI
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-TFSOP (0.724", 18.40mm Width)
- Datasheet:
-
AT45DB321B-TI.pdf
- Description:
- IC FLASH 32MBIT SPI 20MHZ 32TSOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,457
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Product details
Overview
AT45DB321B-TI from Atmel (now Microchip) is a 32-Mbit serial DataFlash memory IC designed for embedded code storage and data logging in resource-constrained systems. It delivers 8192 pages × 528 bytes, supports SPI Mode 0/3 up to 20 MHz, features dual 528-byte SRAM buffers for concurrent read/write, and operates from a single 2.7V–3.6V supply with 4 mA active current - ideal for portable medical devices requiring reliable nonvolatile storage.
For engineers reviewing the AT45DB321B-TI datasheet, AT45DB321B-TI pinout, AT45DB321B-TI application, or AT45DB321B-TI equivalent, key selection considerations include its page-erase flexibility, continuous array read capability for code shadowing, hardware write protection on first 256 pages, and 5.0V-tolerant control pins enabling direct interfacing with 5V microcontrollers.
Technical Context
The AT45DB321B-TI implements a three-level memory architecture (sector/block/page) with dedicated SRAM buffers enabling simultaneous data reception and nonvolatile programming. Its SPI interface uses MSB-first framing, supports both inactive-clock-polarity modes, and requires no external high-voltage programming supply.
Internal self-timed operations - including page erase (tPE), buffer-to-page program with built-in erase (tEP), and main memory page transfer (tXFR) - eliminate external timing management. The RDY/BUSY open-drain output and status register bit 7 provide real-time busy-state visibility during all Group A operations.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Density | 34,603,008 bits (32 Mbit), organized as 8192 × 528-byte pages |
| Supply Voltage | 2.7V–3.6V single supply - eliminates need for voltage translators in 3.3V systems |
| Max Clock Frequency | 20 MHz SPI - enables ~2.5 MB/s sequential read throughput |
| Active Read Current | 4 mA typical - supports battery-powered operation with low duty-cycle access |
| Standby Current | 2 µA typical - critical for ultra-low-power sleep modes in IoT edge nodes |
| Write Protection | Hardware WP pin protects first 256 pages - prevents accidental firmware overwrite |
| Input Tolerance | 5.0V-tolerant SI, SCK, CS, RESET, WP - simplifies interface with legacy 5V logic |
Pinout & Package
AT45DB321B-TI is packaged in a 28-pin TSOP-I (Type 1) with 0.55 mm pitch, compliant with JEDEC MO-153. Pin functions are electrically defined and validated per Atmel datasheet Rev. 2223D.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select | Active-low enable for SPI command initiation; falling edge starts opcode loading |
| SCK | Serial Clock | Input-only clock; data latched on rising edge (in), output on falling edge (out) |
| SI | Serial Input | Input-only data path for opcodes, addresses, and buffer writes |
| SO | Serial Output | Output-only data path for reads and status register; tri-stated when CS high |
| WP | Write Protect | Active-low hardware lock for first 256 pages; internally pulled high |
| RESET | Chip Reset | Active-low hard reset; terminates ongoing operation and resets state machine |
| RDY/BUSY | Ready/Busy Indicator | Open-drain output; low during internal self-timed operations (erase/program/transfer) |
| VCC / GND | Power Supply | Single 2.7–3.6V supply pair; decoupling required within 10 mm of pins |
Key Features
| Feature | Design Value |
|---|---|
| Dual 528-byte SRAM buffers | Enables pipelined operation: receive new data into one buffer while programming the other to Flash |
| Continuous Array Read | Supports seamless code shadowing from Flash to RAM without address reinitialization across page boundaries |
| Page- and block-level erase | Allows selective erasure (single 528-byte page or 8-page block), minimizing wear and latency vs. full-chip erase |
| Self-timed programming | Eliminates external timing circuitry; tEP ≤ 20 ms max ensures deterministic firmware update windows |
| EEPROM emulation support | Three-step Read-Modify-Write enables byte-level updates without external RAM buffering |
Applications
| Firmware Storage | Data Logging |
|---|---|
Use Scenario: Storing boot firmware and application binaries in industrial PLCs where field updates must preserve integrity across power cycles. IC Role / Device Role / Timing Role: Nonvolatile code storage with fast random-access page reads and robust write-protection for critical bootloader sectors. Use Value: Hardware WP pin prevents corruption of first 256 pages containing startup code, ensuring guaranteed boot reliability after brownout events. |
Use Scenario: Capturing sensor readings (temperature, pressure) in battery-powered environmental monitors with multi-day logging intervals. IC Role / Device Role / Timing Role: High-endurance data buffer supporting sequential writes with minimal erase overhead via block-erase optimization. Use Value: Dual SRAM buffers allow background data accumulation while Flash programming occurs, eliminating data loss during write latency. |
| Code Shadowing | Medical Device Configuration |
Use Scenario: Loading executable code from Flash into RAM at startup in portable ultrasound units to meet real-time DSP latency requirements. IC Role / Device Role / Timing Role: Continuous Array Read mode delivers uninterrupted 20 MHz serial stream directly to processor prefetch buffer. Use Value: No inter-page delay during boundary crossing enables deterministic 528-byte-aligned code fetches without software intervention. |
Use Scenario: Storing calibrated sensor offsets, user preferences, and regulatory audit trails in FDA-cleared infusion pumps. IC Role / Device Role / Timing Role: Secure, tamper-resistant parameter storage with hardware write protection and status-register monitored write cycles. Use Value: 2 µA standby current extends battery life between calibrations; RDY/BUSY pin enables safe interrupt-driven write confirmation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial Flash memory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| W25Q32JVSSIQ | 32 Mbit Quad SPI (QSPI), 104 MHz max, no internal buffers, standard SPI only | Lacks dual-buffer concurrency; requires external RAM for pipelined writes | Choose for higher throughput in QSPI-capable hosts where buffer concurrency is unnecessary |
| AT45DB321D-TU | Same architecture, but 32-pin TQFP package; identical electrical specs and command set | Requires PCB redesign due to different footprint and pinout; same functional behavior | Choose only if TSOP layout is unavailable and TQFP mechanical integration is preferred |
Compared with W25Q32JVSSIQ and AT45DB321D-TU, the AT45DB321B-TI uniquely combines SPI simplicity, built-in dual buffers, and hardware write protection - making it optimal for cost-sensitive, low-pin-count designs needing concurrent I/O and firmware safety.
Availability
AT45DB321B-TI is available at Aetrix Electronics and suitable for industrial control, portable medical instrumentation, and automotive telematics requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant sourcing.
Supply support for AT45DB321B-TI 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) is a leading provider of microcontrollers, analog, and memory solutions, emphasizing reliability, longevity, and industrial-grade qualification.
The AT45DB321B-TI belongs to the DataFlash® family - engineered specifically for embedded systems needing SPI-based nonvolatile storage with integrated buffers and simplified firmware update workflows.
FAQ
What is the maximum SPI clock frequency supported by the AT45DB321B-TI?
The AT45DB321B-TI supports a maximum SPI clock frequency of 20 MHz across all supported modes (SPI Mode 0 and Mode 3). This allows sustained sequential read throughput of approximately 2.5 MB/s. The device maintains timing compliance under worst-case VCC = 2.7V and TA = 85°C conditions as specified in the AC characteristics table of the official datasheet Rev. 2223D.
Does the AT45DB321B-TI require a high-voltage programming supply?
No, the AT45DB321B-TI operates entirely from a single 2.7V–3.6V supply for both read and program/erase operations. All internal programming voltages are generated on-chip, eliminating the need for external charge pumps or high-voltage rails. This simplifies power design and improves system reliability in battery-powered and low-voltage embedded applications using the AT45DB321B-TI.
How does the dual-buffer architecture of the AT45DB321B-TI improve system performance?
The AT45DB321B-TI's two independent 528-byte SRAM buffers enable true concurrency: while one buffer is being written via SI, the other can simultaneously program its contents to Flash memory - or vice versa. This eliminates idle time during page reprogramming and supports continuous data streaming in logging or audio playback applications using the AT45DB321B-TI.
Can the AT45DB321B-TI be used with a 5V microcontroller SPI interface?
Yes - the AT45DB321B-TI features 5.0V-tolerant inputs on SI, SCK, CS, RESET, and WP pins. This allows direct connection to 5V logic without level shifters, provided VCC remains within 2.7V–3.6V. The SO pin outputs at VCC levels, so a pull-up to 3.3V is recommended if interfacing with 5V receivers. This compatibility is explicitly confirmed in the Absolute Maximum Ratings and Pin Description sections of the AT45DB321B-TI datasheet.
What happens when the AT45DB321B-TI reaches the end of memory during Continuous Array Read?
During Continuous Array Read, when the AT45DB321B-TI reaches the last bit of the 32-Mbit array, it automatically wraps around to the first bit of page 0 with zero latency - no delay or restart sequence is incurred. This seamless wrap-around behavior is hardware-implemented and enables infinite-loop streaming for audio playback or firmware execution without host-side address management overhead in systems using the AT45DB321B-TI.
AT45DB321B-TI Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 32-TFSOP (0.724", 18.40mm Width)
- 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:
- 20 MHz
- Write Cycle Time - Word, Page:
- 14ms
- Access Time:
- -
- Voltage - Supply:
- 2.7V ~ 3.6V
- Operating Temperature:
- -40°C ~ 85°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 32-TSOP
AT45DB321B-TI FAQ
1.How can I place an order for AT45DB321B-TI through Aetrix?
Please submit a Request for Quotation (RFQ) for AT45DB321B-TI 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 AT45DB321B-TI reliable?
The price and inventory of AT45DB321B-TI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT45DB321B-TI is usually 5 days.
3.What payment methods are accepted for AT45DB321B-TI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT45DB321B-TI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT45DB321B-TI?
AT45DB321B-TI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT45DB321B-TI 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 AT45DB321B-TI?
For technical support, including AT45DB321B-TI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT45DB321B-TI requirements.
6.How does Aetrix verify that AT45DB321B-TI is sourced from the original manufacturer or authorized distributors?
All AT45DB321B-TI 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 AT45DB321B-TI meets industry standards.
7.What is the process for return or replacement of AT45DB321B-TI?
All AT45DB321B-TI units undergo pre-shipment inspection (PSI). If there is an issue with AT45DB321B-TI, 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 AT45DB321B-TI part is unused and in its original packaging.
Return procedure for AT45DB321B-TI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AT45DB321B-TI 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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