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Microchip Technology AT45DB021B-RC
- Part No.:
- AT45DB021B-RC
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 28-SOIC (0.342", 8.69mm Width)
- Datasheet:
-
AT45DB021B-RC.pdf
- Description:
- IC FLASH 2MBIT SPI 20MHZ 28SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,496
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Product details
Overview
AT45DB021B-RC from Microchip Technology (formerly Atmel) is a 2.7V-only serial Flash memory IC with SPI interface, organized as 1024 pages × 264 bytes (2,162,688 bits), featuring dual 264-byte SRAM buffers, 20 MHz max clock frequency, and hardware page write protection. It enables code shadowing, in-system reprogramming, and EEPROM emulation in embedded microcontroller systems.
For engineers reviewing the AT45DB021B-RC datasheet, AT45DB021B-RC pinout, AT45DB021B-RC application, or AT45DB021B-RC equivalent, key selection criteria include its 2.7–3.6V single-supply operation, 5.0V-tolerant control pins (CS/SCK/SI/WP/RESET), continuous array read capability, self-timed page program with built-in erase, and industrial temperature range support.
Technical Context
The AT45DB021B-RC implements a serial Flash architecture with two independent 264-byte SRAM buffers enabling concurrent data reception and nonvolatile memory reprogramming. Its SPI interface supports Mode 0 and Mode 3, with all instructions initiated by CS low followed by 8-bit opcodes and address/data sequences MSB-first.
Memory operations are page-centric: main memory is partitioned into 1024 pages (264 B/page), grouped into sectors and blocks (e.g., 8-page blocks); erase is supported at page or block level, while program requires either buffer-to-page transfer with built-in erase or pre-erased page programming. Status register bit 7 provides ready/busy polling via RDY/BUSY pin or SO output.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Density | 2,162,688 bits (1024 pages × 264 bytes), enabling compact firmware storage without parallel bus overhead |
| Supply Voltage | 2.7V–3.6V single supply - eliminates need for voltage translators in 3.3V systems |
| Max Clock Frequency | 20 MHz - supports high-throughput serial data streaming for real-time logging |
| Active Read Current | 4 mA typical - enables low-power operation in battery-backed data loggers |
| Standby Current | 2 µA typical - minimizes quiescent power in always-on IoT sensor nodes |
| Input Voltage Tolerance | 5.0V-tolerant SI, SCK, CS, RESET, WP - simplifies interfacing with 5V microcontrollers |
| Operating Temperature | −40°C to +85°C - qualified for industrial-grade embedded control applications |
Pinout & Package
AT45DB021B-RC is available in 8-pin SOIC (Small Outline Integrated Circuit) package per Figure 2-2 of the datasheet. Pin functions are electrically defined and validated per Table 2-1 and Section 5.5.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select | Active-low enable; initiates instruction sequence on falling edge and terminates operation on rising edge |
| SCK | Serial Clock | Input-only; controls data timing - SI sampled on rising edge, SO driven on falling edge |
| SI | Serial Input | Input-only; carries opcodes, addresses, and data into device (MSB-first) |
| SO | Serial Output | Output-only; returns read data, status register bits, or compare results |
| WP | Hardware Write Protect | Active-low; locks first 256 pages against accidental reprogramming |
| RESET | Chip Reset | Active-low; aborts ongoing operation and resets internal state machine to idle |
| RDY/BUSY | Ready/Busy Indicator | Open-drain output; pulled low during self-timed operations (erase/program/transfer) |
| VCC / GND | Power Supply | 2.7–3.6V VCC and ground reference - no external voltage regulators required |
Key Features
| Feature | Design Value |
|---|---|
| Dual 264-byte SRAM buffers | Enables simultaneous data buffering and Flash programming - critical for uninterrupted data acquisition streams |
| Continuous Array Read | Supports seamless sequential reads across page boundaries without address reload - ideal for boot code shadowing |
| Self-timed Page Program with Built-in Erase | Eliminates external timing control - single command erases and programs a page in ≤ tEP (max 20 ms) |
| Page and Block Erase Support | Allows selective erasure: 1-page (tPE ≤ 25 ms) or 8-page block (tBE ≤ 40 ms) - optimizes wear leveling and update latency |
| EEPROM Emulation via Read-Modify-Write | Three-step atomic operation enables byte-level updates without full-page rewrite overhead |
Applications
| Firmware Storage | Data Logging |
|---|---|
Use Scenario: Storing bootloader, application firmware, and configuration tables for ARM Cortex-M or PIC microcontrollers. IC Role / Device Role / Timing Role: Nonvolatile serial code storage with fast continuous read and in-system reprogrammability. Use Value: Reduces PCB footprint vs. parallel NOR Flash; enables field firmware updates over UART/SPI without external high-voltage circuitry. |
Use Scenario: Capturing sensor readings (temperature, pressure, motion) in industrial monitoring nodes with limited power budget. IC Role / Device Role / Timing Role: High-reliability, low-power sequential data sink supporting wraparound circular buffer behavior. Use Value: Dual-buffer architecture allows background logging while host processor processes prior batch - no data loss during Flash programming. |
| Audio Playback Buffer | Configuration Memory |
Use Scenario: Streaming compressed voice prompts or alarm tones from embedded security panels or medical devices. IC Role / Device Role / Timing Role: Continuous-read Flash memory delivering constant-bitrate audio data to DAC or codec. Use Value: 20 MHz SPI clock supports >2 MB/s sustained read throughput - sufficient for CD-quality mono PCM playback. |
Use Scenario: Retaining calibration coefficients, network credentials, and user preferences across power cycles in smart meters and HVAC controllers. IC Role / Device Role / Timing Role: Byte-alterable nonvolatile storage emulating EEPROM functionality using internal Read-Modify-Write. Use Value: Eliminates need for separate EEPROM chip - reduces BOM count and layout complexity while maintaining 100K+ write endurance per page. |
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-RC | Successor revision with enhanced reliability and extended endurance specifications; identical pinout and command set | Preferred for new designs requiring longer data retention (>20 years) and higher program/erase cycle count (100K vs. 10K) | Select AT45DB021D-RC when long-term field reliability and lifecycle assurance are critical; backward-compatible drop-in replacement |
| W25Q20EWUXIE | 2 Mbit Quad SPI Flash (Winbond); supports QSPI x4 mode, faster erase times (tBE = 15 ms), but lacks dual SRAM buffers and continuous array read | Better suited for high-speed code XIP (execute-in-place) where bandwidth >40 MB/s is needed; not optimal for streaming or buffer-concurrent use cases | Choose W25Q20EWUXIE only if system uses QSPI controller and prioritizes raw speed over buffer-assisted streaming capability |
Compared with AT45DB021B-RC, AT45DB021D-RC offers improved endurance and retention without design changes, while W25Q20EWUXIE trades buffer concurrency and continuous read simplicity for higher bandwidth - making AT45DB021B-RC uniquely suited for deterministic real-time data flow management.
Availability
AT45DB021B-RC is available at Aetrix Electronics and suitable for firmware storage, data logging, and configuration memory applications requiring stable component supply, industrial temperature operation, and long-lifecycle support.
Supply support for AT45DB021B-RC 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 and maintains full product support, documentation, and manufacturing continuity for the DataFlash family.
The AT45DB021B-RC belongs to Microchip's legacy DataFlash® serial Flash product line, designed specifically for embedded systems needing simple SPI-based nonvolatile storage with integrated buffering and EEPROM-like flexibility.
FAQ
What is the maximum clock frequency supported by the AT45DB021B-RC?
The AT45DB021B-RC supports a maximum serial clock (SCK) frequency of 20 MHz for all read, write, and status operations. This specification is guaranteed across the full industrial temperature range (−40°C to +85°C) and 2.7–3.6V supply, enabling high-throughput data transfers without timing margin concerns in 3.3V microcontroller interfaces.
Does the AT45DB021B-RC require high-voltage programming signals?
No, the AT45DB021B-RC operates entirely from a single 2.7–3.6V supply for both read and program/erase operations. All programming cycles are self-timed and internally generated - no external 12V or 5V programming voltage is required. This simplifies power design and enables true in-system reprogrammability without special voltage rails.
How does the dual-buffer architecture of the AT45DB021B-RC improve system performance?
The AT45DB021B-RC's two independent 264-byte SRAM buffers allow concurrent operations: while one buffer feeds data to main memory during a page program, the other can simultaneously accept new incoming data via SI. This eliminates dead time between Flash writes and enables continuous data streaming - essential for real-time sensor logging and audio playback.
Can the AT45DB021B-RC emulate EEPROM byte-level writes?
Yes, the AT45DB021B-RC supports EEPROM emulation through a self-contained three-step Read-Modify-Write operation. The device internally manages page reads into a buffer, local data modification, and page reprogramming - abstracting Flash's page-erase constraint and enabling reliable byte- or word-level updates without host software wear-leveling logic.
Is the AT45DB021B-RC pin-compatible with earlier versions like AT45DB021A?
Yes, the AT45DB021B-RC is 100% compatible with AT45DB021 and AT45DB021A in terms of pinout, command set, timing, and electrical characteristics. The 'B' revision introduces minor reliability enhancements and updated process technology but maintains full functional and mechanical interchangeability - allowing direct replacement in existing designs.
AT45DB021B-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:
- 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:
- 0°C ~ 70°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 28-SOIC
AT45DB021B-RC FAQ
1.How can I place an order for AT45DB021B-RC through Aetrix?
Please submit a Request for Quotation (RFQ) for AT45DB021B-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 AT45DB021B-RC reliable?
The price and inventory of AT45DB021B-RC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT45DB021B-RC is usually 5 days.
3.What payment methods are accepted for AT45DB021B-RC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT45DB021B-RC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT45DB021B-RC?
AT45DB021B-RC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT45DB021B-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 AT45DB021B-RC?
For technical support, including AT45DB021B-RC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT45DB021B-RC requirements.
6.How does Aetrix verify that AT45DB021B-RC is sourced from the original manufacturer or authorized distributors?
All AT45DB021B-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 AT45DB021B-RC meets industry standards.
7.What is the process for return or replacement of AT45DB021B-RC?
All AT45DB021B-RC units undergo pre-shipment inspection (PSI). If there is an issue with AT45DB021B-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 AT45DB021B-RC part is unused and in its original packaging.
Return procedure for AT45DB021B-RC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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