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Microchip Technology AT45DB021B-TI
- Part No.:
- AT45DB021B-TI
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 28-TSSOP (0.465", 11.80mm Width)
- Datasheet:
-
AT45DB021B-TI.pdf
- Description:
- IC FLASH 2MBIT SPI 20MHZ 28TSOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,541
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Product details
Overview
AT45DB021B-TI from Atmel (now Microchip) is a 2.7V-only serial Flash memory IC with SPI interface, 2 Mbit capacity (1024 × 264-byte pages), dual 264-byte SRAM buffers, and hardware write protection - used for code shadowing, firmware storage, and embedded data logging in microcontroller-based systems.
For engineers reviewing the AT45DB021B-TI datasheet, AT45DB021B-TI pinout, AT45DB021B-TI application, or AT45DB021B-TI equivalent, key selection criteria include 20 MHz SPI timing compliance, page/block erase flexibility, continuous array read capability, 5.0V-tolerant control pins, and industrial temperature support.
Technical Context
The AT45DB021B-TI implements a dedicated SPI-compatible serial interface supporting Mode 0 and Mode 3, eliminating parallel address/data buses and reducing PCB routing complexity. Its architecture separates main Flash memory (1024 pages × 264 bytes) from two independent SRAM buffers, enabling simultaneous buffer loading and Flash reprogramming.
Internally, all program/erase operations are self-timed with no external high-voltage programming required; page-level erase-and-program occurs in a single cycle, and EEPROM-like byte-alterability is achieved via Read-Modify-Write using the buffers. The RDY/BUSY pin and status register bit 7 provide real-time busy-state visibility during these operations.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Capacity | 2,162,688 bits (1024 pages × 264 bytes), organized as 2 Mbit serial Flash |
| Supply Voltage | 2.7V–3.6V single supply - eliminates need for voltage translators in 3.3V systems |
| Max Clock Frequency | 20 MHz SPI clock - supports high-throughput firmware updates and streaming reads |
| Active Read Current | 4 mA typical - enables low-power operation in battery-backed or portable designs |
| Standby Current | 2 µA typical - critical for long-term retention in always-on embedded nodes |
| Interface Protocol | SPI Mode 0/3 compatible - ensures interoperability with ARM Cortex-M, PIC, and ESP32 host controllers |
| Input Tolerance | 5.0V-tolerant SI, SCK, CS, RESET, WP - simplifies level-shifting in mixed-voltage systems |
Pinout & Package
AT45DB021B-TI is available in 8-pin SOIC (JEDEC MS-012AA), 28-pin SOIC, and 28-pin CBGA packages. Pin functions are consistent across variants; the 8-pin SOIC is most common for space-constrained applications.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select | Active-low enable for SPI command initiation; must remain low during full instruction sequence |
| SCK | Serial Clock | Input-only clock; data latched on rising edge (SI), output on falling edge (SO) |
| SI | Serial Input | Command, address, and data input path - accepts opcodes (e.g., 52H for page read) |
| SO | Serial Output | Output-only data path - delivers read data, status register bits, or buffer contents |
| WP | Hardware Write Protect | Low = lock first 256 pages; high = enable full memory reprogrammability |
| RESET | Chip Reset | Asynchronous active-low reset - terminates ongoing operation and returns state machine to idle |
| RDY/BUSY | Open-drain status indicator | Pulled low during internal self-timed operations (e.g., tEP = 20 ms max page program) |
| VCC / GND | Power supply terminals | 2.7–3.6V VCC; decoupling capacitor required per datasheet layout guidelines |
Key Features
| Feature | Design Value |
|---|---|
| Dual SRAM buffers (264 B each) | Enables pipelined operation: receive new data into one buffer while programming Flash from the other |
| Continuous Array Read | Supports seamless code shadowing - automatic page-wrap without delay at boundaries |
| Page + Block Erase | Flexible granularity: erase single 264-byte page or 8-page block (2112 bytes) to optimize wear leveling |
| Hardware Data Protection | WP pin physically disables programming of first 256 pages - prevents accidental bootloader overwrite |
| Self-timed programming | No external timing control needed; internal logic manages erase/program cycles and status reporting |
Applications
| Bootloader Storage | Firmware Update Log |
|---|---|
Use Scenario: Storing immutable bootloader code in embedded systems requiring secure, field-upgradable firmware. IC Role / Device Role / Timing Role: Nonvolatile storage for primary boot image accessed at power-on reset via SPI. Use Value: Continuous Array Read enables fast shadow-copy to RAM; hardware WP prevents corruption during update failures. | Use Scenario: Logging version history, checksums, and update timestamps during OTA firmware deployments. IC Role / Device Role / Timing Role: High-endurance data logging buffer with page-erase granularity to extend write-cycle lifetime. Use Value: Dual buffers allow concurrent log entry capture and background Flash commit - no data loss during reprogramming. |
| Audio Sample Buffer | Industrial Sensor Configuration |
Use Scenario: Storing pre-recorded voice prompts or audio samples in medical or home automation devices. IC Role / Device Role / Timing Role: Low-latency sequential read memory interfaced directly to DAC or audio processor. Use Value: 20 MHz SPI and zero-delay page boundary crossing ensure uninterrupted playback without CPU intervention. | Use Scenario: Retaining calibrated sensor offsets, compensation tables, and device-specific parameters in factory-configured modules. IC Role / Device Role / Timing Role: Secure, tamper-resistant parameter store accessible only after authentication handshake. Use Value: 5.0V-tolerant WP and RESET pins simplify integration with industrial 5V I/O subsystems while maintaining 3.3V core 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 |
|---|---|---|---|
| AT45DB021D-TI | Successor with enhanced reliability, same pinout and command set; supports extended temperature range (−40°C to +105°C) | Required for automotive or extended industrial environments where AT45DB021B-TI's −40°C to +85°C rating is insufficient | Select AT45DB021D-TI when lifecycle longevity and wider thermal margin are mandatory. |
| W25Q20EWUXIE | 2 Mbit Quad SPI Flash (Winbond); supports QPI/DTR modes, faster 104 MHz dual/quad read, but lacks dual SRAM buffers and continuous array read | Preferred for high-speed code execution from Flash; unsuitable for buffer-assisted streaming or EEPROM emulation workflows | Choose W25Q20EWUXIE only if system requires quad-I/O bandwidth and does not rely on AT45DB021B-TI's buffer-based Read-Modify-Write capability. |
Compared with AT45DB021D-TI, the AT45DB021B-TI offers identical functionality but with narrower temperature tolerance and earlier revision silicon; versus W25Q20EWUXIE, it trades raw speed for deterministic streaming and built-in data buffering - making it superior for real-time data acquisition and firmware resilience use cases.
Availability
AT45DB021B-TI is available at Aetrix Electronics and suitable for bootloader storage, firmware update logging, and audio sample buffering requiring stable component supply across industrial design cycles.
Supply support for AT45DB021B-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 (formerly Atmel) is a global semiconductor manufacturer specializing in microcontrollers, analog, Flash memory, and security solutions for embedded systems.
The AT45DB021B-TI belongs to the DataFlash® family - designed specifically to replace parallel EEPROM/Flash in space- and pin-constrained applications while delivering SPI simplicity, buffer-assisted throughput, and robust in-system reprogrammability.
FAQ
What is the maximum SPI clock frequency supported by the AT45DB021B-TI?
The AT45DB021B-TI supports a maximum SPI clock frequency of 20 MHz for all read, write, and command operations. This timing is validated across the full operating voltage range (2.7V–3.6V) and commercial/industrial temperature grades. Exceeding 20 MHz may result in command rejection or data corruption, as confirmed in the AC Characteristics table of the official Microchip datasheet (Doc ID: 1937J).
Does the AT45DB021B-TI require external high-voltage programming?
No, the AT45DB021B-TI does not require external high-voltage programming. All erase and program operations are performed using only the 2.7V–3.6V VCC supply. Internal charge pumps generate necessary voltages, enabling true single-supply in-system reprogrammability - a core design feature of the DataFlash® architecture.
How does the dual-buffer architecture of the AT45DB021B-TI improve system performance?
The AT45DB021B-TI's two independent 264-byte SRAM buffers enable overlapping operations: while one buffer streams data to Flash (e.g., Buffer 1 → Page 5), the host can simultaneously load new data into the other buffer (e.g., Buffer 2 ← SI). This pipelining eliminates idle time between page writes and is essential for sustained data logging or real-time firmware patching without CPU stalls.
Can the AT45DB021B-TI be used for EEPROM emulation, and how is it implemented?
Yes, the AT45DB021B-TI supports EEPROM emulation via its built-in three-step Read-Modify-Write operation. The host reads a page into a buffer, modifies target bytes, then writes the updated buffer back to Flash - all using standard AT45DB021B-TI opcodes (e.g., 53H, 83H). This avoids external EEPROM and leverages the device's page-erase flexibility to minimize wear.
What is the purpose of the RDY/BUSY pin on the AT45DB021B-TI, and how should it be used?
The RDY/BUSY pin on the AT45DB021B-TI is an open-drain output that goes low during any internally self-timed operation (e.g., page program, block erase, buffer transfer). It allows the host to poll readiness without reading the status register. A 1 kΩ external pull-up resistor is required. Using RDY/BUSY reduces SPI traffic and improves determinism compared to polling bit 7 of the status register.
AT45DB021B-TI Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 28-TSSOP (0.465", 11.80mm Width)
- Packaging:
- Tray
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- FLASH
- Technology:
- FLASH
- Memory Size:
- 2Mbit
- Memory Organization:
- 264 Bytes x 1024 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:
- 28-TSOP
AT45DB021B-TI FAQ
1.How can I place an order for AT45DB021B-TI through Aetrix?
Please submit a Request for Quotation (RFQ) for AT45DB021B-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 AT45DB021B-TI reliable?
The price and inventory of AT45DB021B-TI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT45DB021B-TI is usually 5 days.
3.What payment methods are accepted for AT45DB021B-TI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT45DB021B-TI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT45DB021B-TI?
AT45DB021B-TI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT45DB021B-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 AT45DB021B-TI?
For technical support, including AT45DB021B-TI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT45DB021B-TI requirements.
6.How does Aetrix verify that AT45DB021B-TI is sourced from the original manufacturer or authorized distributors?
All AT45DB021B-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 AT45DB021B-TI meets industry standards.
7.What is the process for return or replacement of AT45DB021B-TI?
All AT45DB021B-TI units undergo pre-shipment inspection (PSI). If there is an issue with AT45DB021B-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 AT45DB021B-TI part is unused and in its original packaging.
Return procedure for AT45DB021B-TI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AT45DB021B-TI Tags
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