My Inquiry
My Account
Microchip Technology AT26DF321-SU
- Part No.:
- AT26DF321-SU
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-SOIC (0.209", 5.30mm Width)
- Datasheet:
-
AT26DF321-SU.pdf
- Description:
- IC FLASH 32MBIT SPI 66MHZ 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,712
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
AT26DF321-SU from Adesto Technologies (now part of Dialog Semiconductor) is a 32-Mbit serial SPI Flash memory IC designed for code shadowing and data storage in embedded systems. It operates from a single 2.7V–3.6V supply, supports SPI Modes 0/3 up to 66 MHz, and features uniform 4-Kbyte/32-Kbyte/64-Kbyte erase blocks and individual sector protection - enabling reliable firmware updates in industrial controllers and IoT edge nodes.
For engineers reviewing the AT26DF321-SU datasheet, AT26DF321-SU pinout, AT26DF321-SU application, or AT26DF321-SU equivalent, key selection considerations include its flexible erase granularity, hardware write-protect (WP) pin support, deep power-down current (4 µA), JEDEC-compliant ID read, and compatibility with standard SPI masters in resource-constrained microcontroller-based designs.
Technical Context
The AT26DF321-SU implements a serial peripheral interface with strict timing alignment: input data latched on SCK rising edge, output data clocked on falling edge. Its internal architecture includes a 32-Mbit (4-Mbyte) memory array segmented into sixty-four 64-Kbyte physical sectors, each individually lockable via software commands or hardware WP pin assertion.
Erase operations are fully self-timed and verified - block erases (4/32/64 Kbyte) and chip erase use dedicated opcodes (20h/52h/D8h/60h/C7h), while program operations support 1–256-byte page writes (02h). Status Register polling (05h) enables real-time busy/EPE (erase-program error) detection without fixed delay waits.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Density | 32 Mbit (4 Mbyte) - sufficient for boot code + application firmware in mid-tier MCUs. |
| Supply Voltage | 2.7V–3.6V - compatible with 3.3V logic systems; no VPP or charge pump required. |
| Max Clock Frequency | 66 MHz - enables high-throughput read access; supports fast SPI mode for reduced latency. |
| Erase Granularity | 4-Kbyte / 32-Kbyte / 64-Kbyte blocks + full chip - minimizes wasted space during partial firmware updates. |
| Endurance | 100,000 program/erase cycles - validated for field-upgradable firmware requiring frequent patching. |
| Data Retention | 20 years at 85°C - meets industrial-grade reliability requirements for unattended deployments. |
| Deep Power-Down Current | 4 µA typical - enables ultra-low-power sleep modes in battery-operated sensors and wearables. |
| Operating Temperature | −40°C to +85°C - qualified for full industrial temperature range without derating. |
Pinout & Package
AT26DF321-SU is available in an 8-lead SOIC (208-mil wide) package. Pin functions are electrically defined per JEDEC MS-012, with no NC pins in this variant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select | Active-low enable; must transition high→low to initiate command, low→high to terminate - ensures precise SPI transaction framing. |
| SCK | Serial Clock | Master-generated clock; rising edge latches SI, falling edge clocks SO - defines deterministic setup/hold timing. |
| SI | Serial Input | Command/address/data input path; MSB-first; requires stable setup before SCK rising edge. |
| SO | Serial Output | Read data output; tri-stated when CS high - allows bus sharing with other SPI slaves. |
| WP | Write Protect | Hardware lock for sector protection; low = enable protection; internally pulled high - prevents accidental writes during power transients. |
| VCC | Power Supply | 2.7–3.6V primary supply; powers core logic and memory array - decoupling capacitor mandatory near pin. |
| GND | Ground Reference | Return path for all currents; must be low-impedance connection to system ground plane. |
Key Features
| Feature | Design Value |
|---|---|
| Uniform Erase Architecture | Four granular erase options (4/32/64 Kbyte + full chip) reduce wasted memory during partial firmware updates. |
| Individual Sector Protection | 64 independent 64-Kbyte sectors can be locked/unlocked via command or WP pin - isolates critical bootloader from application updates. |
| Automatic Erase/Program Verification | Status Register EPE bit flags failed operations - eliminates need for external verification logic or redundant reads. |
| JEDEC Standard ID Read | 9Fh command returns manufacturer (0x1F) and device ID (0x47) - enables runtime flash identification and BOM validation. |
| Low-Power Deep Power-Down | B9h command reduces ICC to 4 µA; ABh resumes operation - extends battery life in always-on sensor nodes. |
| Flexible Page Programming | 1–256 byte writes within same 256-byte page boundary - supports fine-grained data logging without full-page overhead. |
Applications
| Industrial PLC Firmware Storage | Medical Device Bootloader Memory |
|---|---|
Use Scenario: Storing and updating ladder logic firmware in programmable logic controllers with field serviceability requirements. IC Role / Device Role / Timing Role: Non-volatile code storage with atomic sector erase - enables safe over-the-air (OTA) updates without halting control loop execution. Use Value: 4-Kbyte erase blocks allow patching of single function blocks; hardware WP pin prevents corruption during brown-out events. | Use Scenario: Holding certified bootloader and diagnostic firmware in Class II medical instruments requiring traceable revision control. IC Role / Device Role / Timing Role: Secure, tamper-resistant firmware repository - uses Global Protect to lock bootloader sector and individual Unprotect for diagnostic module updates. Use Value: 100,000 endurance cycles support >10 years of calibration updates; 20-year data retention satisfies FDA long-term recordkeeping mandates. |
| Smart Meter Data Logging | Automotive Infotainment Configuration |
Use Scenario: Recording time-stamped energy consumption data in ANSI C12.19-compliant utility meters with 10+ year deployment life. IC Role / Device Role / Timing Role: High-reliability data buffer - leverages 64-Kbyte sectoring to isolate daily logs from monthly summaries and firmware metadata. Use Value: Deep power-down (4 µA) extends battery backup life; 85°C rating ensures operation inside sealed meter enclosures. | Use Scenario: Storing UI skin assets, language packs, and vehicle-specific configuration profiles in automotive head units. IC Role / Device Role / Timing Role: SPI-connected asset storage - uses 66 MHz read speed to stream compressed graphics without frame drops. Use Value: Uniform 32-Kbyte erase blocks align with OTA update packet sizes; RoHS-compliant green packaging meets automotive ELV directives. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial Flash memory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT25DF321A-SU | Successor device with identical pinout, density, and voltage; improved tCH (chip erase time) and enhanced ESD robustness. | Same industrial temperature range and sector protection model; adds dual/quad SPI support in later revisions. | Select AT25DF321A-SU for new designs requiring extended lifecycle support and marginally faster erase performance. |
| MX25L3206EM2I-12G | 32-Mbit SPI Flash with 104 MHz max clock, 2.7–3.6V supply, but only 4-Kbyte/64-Kbyte erase blocks (no 32-Kbyte option). | Lacks hardware WP pin; relies solely on software protection - increases MCU firmware complexity for secure updates. | Choose MX25L3206EM2I-12G only if higher read bandwidth is critical and 32-Kbyte erase granularity is not required. |
Compared with AT26DF321-SU, AT25DF321A-SU offers backward-compatible improvements for longevity, while MX25L3206EM2I-12G trades erase flexibility and hardware write protection for raw read speed - making AT26DF321-SU optimal where update safety and partial-block efficiency are prioritized over peak throughput.
Availability
AT26DF321-SU is available at Aetrix Electronics and suitable for industrial PLCs, medical diagnostics equipment, smart utility meters, and automotive infotainment systems requiring stable component supply across multi-year production cycles.
Supply support for AT26DF321-SU 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
Adesto Technologies, acquired by Dialog Semiconductor in 2020, specialized in low-power, high-reliability non-volatile memory solutions for industrial and IoT applications.
The AT26DF321-SU belongs to Adesto's DataFlash® family, engineered specifically for embedded systems needing efficient code shadowing and robust field-upgradable data storage with minimal power and board space overhead.
FAQ
What is the maximum SPI clock frequency supported by the AT26DF321-SU?
The AT26DF321-SU supports a maximum clock frequency of 66 MHz for standard read operations using the 0Bh opcode. This enables high-speed data streaming in applications like firmware loading or graphics asset retrieval. The device also supports lower-frequency reads (up to fRDLF) using the 03h opcode for noise-sensitive environments. All timing parameters, including tVSL (CS setup) and tVCL (CS hold), are specified in the official datasheet revision 3633F.
Does the AT26DF321-SU require a separate programming voltage?
No, the AT26DF321-SU does not require a separate programming voltage. It performs all read, program, and erase operations using only the main VCC supply (2.7V–3.6V). Internal charge pumps generate necessary high voltages for memory cell manipulation, eliminating the need for external VPP circuitry and simplifying PCB design for cost-sensitive embedded systems.
How many physical sectors does the AT26DF321-SU have, and what is their size?
The AT26DF321-SU contains sixty-four uniform 64-Kbyte physical sectors, totaling 4,194,304 bytes (32 Mbit). Each sector can be individually protected or unprotected via software commands (36h/39h) or globally controlled using the Write Status Register. This architecture enables precise isolation of bootloader, application, and data regions without memory waste.
Can the AT26DF321-SU be used in battery-powered applications?
Yes, the AT26DF321-SU is well-suited for battery-powered applications due to its 4 µA typical deep power-down current (B9h command) and 7 mA active read current. Its ability to retain data for 20 years at 85°C and operate across −40°C to +85°C makes it ideal for remote sensors, portable medical devices, and smart meter backup storage where energy efficiency and long-term reliability are critical.
Is the AT26DF321-SU pin-compatible with the AT25DF321A-SU?
Yes, the AT26DF321-SU is pin-compatible and functionally compatible with the AT25DF321A-SU, which is its direct successor. Both share identical 8-lead SOIC packaging, pinout, supply voltage range, command set, and sector protection architecture. Migration to AT25DF321A-SU is recommended for new designs due to extended product lifecycle and minor performance enhancements, with no PCB or firmware changes required.
AT26DF321-SU 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:
- 32Mbit
- Memory Organization:
- 256 Bytes x 16384 pages
- Memory Interface:
- SPI
- Clock Frequency:
- 66 MHz
- Write Cycle Time - Word, Page:
- 6µs, 5ms
- 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-SOIC
AT26DF321-SU FAQ
1.How can I place an order for AT26DF321-SU through Aetrix?
Please submit a Request for Quotation (RFQ) for AT26DF321-SU 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 AT26DF321-SU reliable?
The price and inventory of AT26DF321-SU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT26DF321-SU is usually 5 days.
3.What payment methods are accepted for AT26DF321-SU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT26DF321-SU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT26DF321-SU?
AT26DF321-SU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT26DF321-SU 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 AT26DF321-SU?
For technical support, including AT26DF321-SU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT26DF321-SU requirements.
6.How does Aetrix verify that AT26DF321-SU is sourced from the original manufacturer or authorized distributors?
All AT26DF321-SU 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 AT26DF321-SU meets industry standards.
7.What is the process for return or replacement of AT26DF321-SU?
All AT26DF321-SU units undergo pre-shipment inspection (PSI). If there is an issue with AT26DF321-SU, 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 AT26DF321-SU part is unused and in its original packaging.
Return procedure for AT26DF321-SU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AT26DF321-SU 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…
