My Inquiry
My Account
Microchip Technology AT45DB021B-SC
- Part No.:
- AT45DB021B-SC
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-SOIC (0.209", 5.30mm Width)
- Datasheet:
-
AT45DB021B-SC.pdf
- Description:
- IC FLASH 2MBIT SPI 20MHZ 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,267
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
AT45DB021B-SC from Microchip Technology (formerly Atmel) 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. It enables concurrent data buffering and nonvolatile reprogramming in embedded code storage and firmware update applications.
For engineers reviewing the AT45DB021B-SC datasheet, AT45DB021B-SC pinout, AT45DB021B-SC application, or AT45DB021B-SC equivalent, key selection criteria include its 20 MHz SPI clock support, page/block erase flexibility, continuous array read for code shadowing, 5.0V-tolerant control pins, and industrial temperature range compatibility.
Technical Context
The AT45DB021B-SC implements a serial Flash architecture with two independent 264-byte SRAM buffers enabling simultaneous receive-and-program operation. 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.
Memory organization comprises 1024 pages of 264 bytes each (2,162,688 bits total), plus sector/block/page-level erasability. Internal self-timed programming eliminates external timing control, and status register bit 7 provides real-time RDY/BUSY monitoring via SO or dedicated RDY/BUSY pin.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Density | 2,162,688 bits (1024 pages × 264 bytes); supports byte-alterable EEPROM emulation via Read-Modify-Write |
| SPI Clock Frequency | Up to 20 MHz; enables high-throughput firmware updates and streaming read operations |
| Supply Voltage | 2.7 V – 3.6 V only; no high-voltage programming required, simplifying power design |
| Active Read Current | 4 mA typical; reduces system power budget during code execution or data retrieval |
| Standby Current | 2 µA typical; suitable for battery-backed or ultra-low-power wake-on-event systems |
| Write Protection | Hardware WP pin protects first 256 pages; prevents accidental firmware corruption during field updates |
| Input Tolerance | 5.0 V tolerant on SI, SCK, CS, RESET, WP; allows direct interfacing with 5 V microcontrollers without level shifters |
Pinout & Package
AT45DB021B-SC is available in 8-pin SOIC (Small Outline Integrated Circuit) package per Figure 2-2, with gull-wing leads, RoHS-compliant green packaging, and standard JEDEC MS-012AC footprint.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select | Active-low enable; initiates instruction sequence and defines SPI transaction boundaries |
| 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; 5.0 V tolerant |
| SO | Serial Output | Output-only; returns read data and status register bits; tri-stated when CS high |
| WP | Write Protect | Active-low hardware lock for first 256 pages; 5.0 V tolerant; must be high to program protected region |
| RESET | Chip Reset | Active-low asynchronous abort; resets internal state machine without power cycle; 5.0 V tolerant |
| RDY/BUSY | Ready/Busy Indicator | Open-drain output; pulled low during self-timed operations (erase, program, transfer); enables polling-free interrupt-driven control |
| VCC / GND | Power Supply | Single 2.7–3.6 V supply; GND reference for all I/O; no separate VIO required |
Key Features
| Feature | Design Value |
|---|---|
| Dual SRAM Buffers | Two independent 264-byte buffers allow overlapping data reception and Flash programming-eliminates host wait states during page writes |
| Continuous Array Read | Supports seamless code shadowing: automatic address wrap-around across page and array boundaries with no latency at boundaries |
| Page-Level Reprogramming | Single-cycle erase-and-program per page (tEP ≤ 20 ms); no separate erase step needed before write-reduces firmware update time |
| Block Erase Capability | Erase 8-page blocks (2112 bytes) in one command (tBE ≤ 15 ms); accelerates bulk data writes compared to individual page erases |
| Hardware Data Protection | WP pin + status register bit 7 (RDY/BUSY) + RESET pin provide three-layer reliability for mission-critical firmware storage |
Applications
| Boot Code Storage | Firmware Over-the-Air (OTA) Updates |
|---|---|
Use Scenario: Storing bootloader and primary application firmware in embedded microcontroller systems requiring fast, reliable startup. IC Role / Device Role / Timing Role: Nonvolatile code storage with continuous array read capability for zero-latency instruction fetch during boot. Use Value: Eliminates need for external parallel Flash or SRAM shadowing; reduces BOM count and PCB area while maintaining deterministic boot timing. | Use Scenario: Receiving and validating new firmware images wirelessly in IoT edge nodes before committing to persistent storage. IC Role / Device Role / Timing Role: Dual-buffered Flash memory enabling background download into buffer while active firmware runs from main memory. Use Value: Enables atomic firmware swap with no service interruption-buffer-to-memory program with built-in erase ensures consistent post-update state. |
| Audio Voice Recording | Industrial Sensor Data Logging |
Use Scenario: Capturing and storing voice prompts or alarm messages in security panels and home automation hubs. IC Role / Device Role / Timing Role: High-density serial Flash with low active current (4 mA) and 2 µA standby for intermittent record-and-playback cycles. Use Value: Extends battery life in portable voice devices; page erase granularity allows selective overwrite of oldest recordings without full array erase. | Use Scenario: Long-term timestamped logging of temperature, pressure, or vibration data in factory floor controllers and predictive maintenance gateways. IC Role / Device Role / Timing Role: Robust nonvolatile storage with hardware WP and RDY/BUSY signaling for reliable write-integrity under electrical noise. Use Value: Prevents data corruption during brown-out or reset events; block erase supports efficient circular buffer management over weeks/months of operation. |
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-SC | Successor revision with enhanced endurance (100k program/erase cycles vs. 10k) and extended temperature range (–40°C to +85°C vs. 0°C to +70°C) | Required for extended-life industrial deployments or wider ambient operating conditions | Select AT45DB021D-SC for new designs needing higher reliability; AT45DB021B-SC remains valid for commercial-grade cost-sensitive applications |
| W25Q20CLSNIG | 2 Mbit Quad SPI Flash (Winbond); supports QSPI x4 mode, faster max clock (104 MHz), but lacks dual SRAM buffers and continuous array read | Preferred where host MCU supports QSPI and throughput >20 MB/s is critical; unsuitable for code shadowing or buffer-concurrent operation | Choose W25Q20CLSNIG only if QSPI bandwidth is mandatory and dual-buffer concurrency is not required |
Compared with AT45DB021D-SC, the AT45DB021B-SC offers lower cost and proven field reliability but reduced endurance and narrower temperature range; versus W25Q20CLSNIG, it trades raw speed for unique buffer-concurrent operation and seamless code shadowing-making it irreplaceable in latency-sensitive embedded boot and OTA architectures.
Availability
AT45DB021B-SC is available at Aetrix Electronics and suitable for boot code storage, firmware OTA updates, audio voice recording, and industrial sensor data logging requiring stable component supply and long-term production continuity.
Supply support for AT45DB021B-SC 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 delivering scalable, secure, and intelligent solutions for embedded control, connectivity, and memory applications.
The AT45DB021B-SC belongs to Microchip's DataFlash® family-designed specifically for embedded systems needing SPI-based nonvolatile memory with integrated SRAM buffers to enable concurrent data handling and deterministic code execution.
FAQ
What is the maximum SPI clock frequency supported by the AT45DB021B-SC?
The AT45DB021B-SC supports a maximum SPI clock frequency of 20 MHz for all read, write, and status operations. This specification is guaranteed across the full commercial temperature range (0°C to +70°C) and 2.7–3.6 V supply voltage. The AT45DB021B-SC uses standard SPI Mode 0 and Mode 3 timing, with data sampled on the rising edge of SCK and output on the falling edge.
Does the AT45DB021B-SC require a high-voltage programming supply?
No, the AT45DB021B-SC operates entirely from a single 2.7–3.6 V supply for both read and program/erase operations. All programming cycles-including page erase, buffer-to-memory program, and auto page rewrite-are internally self-timed and require no external high-voltage source. This eliminates the need for charge pumps or auxiliary power rails, simplifying system design and reducing bill-of-materials cost for the AT45DB021B-SC.
How does the dual-buffer architecture of the AT45DB021B-SC improve system performance?
The AT45DB021B-SC integrates two independent 264-byte SRAM buffers that operate concurrently with main memory programming. While one buffer receives new data via SI, the other can be written to Flash-or vice versa-enabling zero-wait-state firmware updates and continuous data streaming. This architecture directly reduces host CPU overhead and eliminates idle time during AT45DB021B-SC page programming cycles.
Can the AT45DB021B-SC be used for code shadowing, and what feature enables this?
Yes, the AT45DB021B-SC supports true code shadowing via its Continuous Array Read command (opcodes 68H/E8H). This mode enables uninterrupted sequential read across page and array boundaries with automatic address wrap-around and no latency penalties at boundaries. The AT45DB021B-SC delivers deterministic instruction fetch timing ideal for bootloaders and real-time firmware execution without external SRAM caching.
Is the AT45DB021B-SC pin-compatible with earlier versions like AT45DB021 and AT45DB021A?
Yes, the AT45DB021B-SC is 100% compatible with AT45DB021 and AT45DB021A in terms of pinout, command set, timing, and electrical specifications. The AT45DB021B-SC maintains identical SOIC-8 packaging, identical SPI interface behavior, and backward-compatible opcodes-allowing drop-in replacement in existing designs without layout or firmware changes.
AT45DB021B-SC Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-SOIC (0.209", 5.30mm 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:
- 8-SOIC
AT45DB021B-SC FAQ
1.How can I place an order for AT45DB021B-SC through Aetrix?
Please submit a Request for Quotation (RFQ) for AT45DB021B-SC 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-SC reliable?
The price and inventory of AT45DB021B-SC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT45DB021B-SC is usually 5 days.
3.What payment methods are accepted for AT45DB021B-SC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT45DB021B-SC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT45DB021B-SC?
AT45DB021B-SC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT45DB021B-SC 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-SC?
For technical support, including AT45DB021B-SC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT45DB021B-SC requirements.
6.How does Aetrix verify that AT45DB021B-SC is sourced from the original manufacturer or authorized distributors?
All AT45DB021B-SC 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-SC meets industry standards.
7.What is the process for return or replacement of AT45DB021B-SC?
All AT45DB021B-SC units undergo pre-shipment inspection (PSI). If there is an issue with AT45DB021B-SC, 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-SC part is unused and in its original packaging.
Return procedure for AT45DB021B-SC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AT45DB021B-SC 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…
