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Microchip Technology AT25256-10UI-1.8
- Part No.:
- AT25256-10UI-1.8
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-VFBGA
- Datasheet:
-
AT25256-10UI-1.8.pdf
- Description:
- IC EEPROM 256KBIT SPI 8DBGA
- Quantity:
- Payment:
- Shipping:
Inventory:4,385
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Product details
Overview
AT25256-10UI-1.8 from Microchip Technology (formerly Atmel) is a 256 Kbit (32,768 × 8) SPI serial EEPROM optimized for low-voltage embedded systems. It operates from 1.8 V to 3.6 V, supports 3 MHz clock rate, features 64-byte page write capability, and delivers >200 years data retention with 100,000 write cycles - used in industrial sensor calibration storage and firmware parameter backup.
For engineers reviewing the AT25256-10UI-1.8 datasheet, AT25256-10UI-1.8 pinout, AT25256-10UI-1.8 application, or AT25256-10UI-1.8 equivalent, key selection criteria include 1.8 V operation margin, hardware/software write protection via WP/HOLD pins, SOIC-8 package compatibility, and SPI Mode 0/3 interoperability with microcontroller peripherals.
Technical Context
The AT25256-10UI-1.8 implements a synchronous SPI slave interface with separate SI (input) and SO (output) lines, requiring CS activation and MSB-first data framing. Its internal 8-bit instruction register accepts op-codes including WREN, WRITE, RDSR, and WRSR to manage memory access and status control.
Block write protection is configured nonvolatively via BP0/BP1 bits in the status register, enabling selective locking of top 1/4, 1/2, or full 32 KB array. The HOLD pin suspends ongoing transfers without resetting sequence state, while WP pin - when enabled via WPEN bit - blocks status register writes during low assertion.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 256 Kbit (32,768 × 8 bytes) - sufficient for bootloader configuration, device ID, and runtime calibration tables. |
| Supply Voltage | 1.8 V to 3.6 V - enables direct interfacing with 1.8 V/3.3 V logic domains without level shifting. |
| Max Clock Frequency | 3 MHz at 1.8–3.6 V - supports high-throughput parameter updates in real-time control loops. |
| Write Cycle Time | 5 ms typical - determines minimum latency between successive page writes in logging applications. |
| Endurance | 100,000 write cycles - ensures reliability over 10+ years in daily-configurable industrial HMI systems. |
| Data Retention | >200 years at 25°C - guarantees long-term integrity of factory-trimmed sensor coefficients and security keys. |
| ESD Protection | >4000 V HBM - provides robustness against handling and board-level electrostatic discharge events. |
Pinout & Package
AT25256-10UI-1.8 is housed in an 8-pin EIAJ SOIC (0.200" wide) package, compliant with JEDEC MS-012 standard. Pin 1 is marked by a notch or index dot; leads are gull-wing shaped with 1.27 mm pitch.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (CS) | Chip Select | Active-low enable signal - must be asserted before any SPI transaction; deassertion places SO in high-impedance state. |
| 2 (SCK) | Serial Clock | Master-generated clock input - synchronizes all SI/SO data transfers; supports Mode 0 (CPOL=0, CPHA=0) and Mode 3 (CPOL=1, CPHA=1). |
| 3 (SI) | Serial Data Input | MOSI line - receives op-codes, addresses, and write data; ignored during HOLD or CS high. |
| 4 (SO) | Serial Data Output | MISO line - outputs read data and status register contents; tri-stated when CS high or during HOLD. |
| 5 (WP) | Write Protect | Hardware lock - when WPEN=1 and WP=low, prevents status register modification and protected memory writes. |
| 6 (HOLD) | Hold Control | Suspends active SPI transfer - allows master to pause communication mid-sequence without losing address/state context. |
| 7 (GND) | Ground Reference | 0 V return path for VCC and I/O signals - requires low-impedance connection to system ground plane. |
| 8 (VCC) | Power Supply | 1.8–3.6 V core supply - bypass capacitor (0.1 µF ceramic) required within 10 mm of pin for noise immunity. |
Key Features
| Feature | Design Value |
|---|---|
| Triple voltage option support | 1.8 V, 2.7 V, and 5.0 V variants share identical pinout and instruction set - simplifies BOM consolidation across product tiers. |
| Page write mode | 64-byte burst programming reduces write latency by 94% vs. byte-wise writes - critical for fast firmware patching in field-upgradeable devices. |
| Nonvolatile block protection | BP0/BP1 bits retain protection settings across power cycles - eliminates need for boot-time reconfiguration of secure memory regions. |
| Dual write protection | Combines hardware (WP pin) and software (WRSR command) methods - enables layered security for factory-programmed keys and user-modifiable parameters. |
| Industrial temperature range | -40°C to +85°C operation - validated for deployment in motor drives, PLC I/O modules, and outdoor metering equipment. |
Applications
| Industrial Sensor Calibration Storage | Firmware Parameter Backup |
|---|---|
|
Use Scenario: Storing factory-trimmed offset/gain coefficients for analog sensor front-ends in programmable logic controllers. IC Role / Device Role / Timing Role: Nonvolatile parameter repository accessed during power-on initialization and runtime recalibration routines. Use Value: Eliminates external trim potentiometers and enables automated calibration via host MCU, reducing manufacturing test time by 35%. |
Use Scenario: Preserving user-configured operating modes, network settings, and alarm thresholds in smart HVAC controllers. IC Role / Device Role / Timing Role: Persistent configuration store updated only on user action or fault recovery - isolated from volatile RAM. Use Value: Ensures settings survive brownouts and hot resets, maintaining operational continuity without requiring reconfiguration after power loss. |
| Embedded Bootloader Configuration | Secure Key Storage for Authentication |
|
Use Scenario: Holding boot source selection flags, image validation hashes, and watchdog timeout values in medical diagnostic equipment. IC Role / Device Role / Timing Role: Early-boot configuration manager - read before main application starts to determine execution path and security policy. Use Value: Enables fail-safe dual-image boot and cryptographic signature verification without adding FPGA or dedicated secure element cost. |
Use Scenario: Storing device-unique AES keys and certificate fingerprints in IoT edge gateways supporting TLS mutual authentication. IC Role / Device Role / Timing Role: Tamper-resistant key vault - write-protected sections prevent overwrite during firmware updates or remote commands. Use Value: Meets IEC 62443-3-3 SL2 requirements for key confidentiality by combining hardware WP pin lock and BP0/BP1 array segmentation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| M95256-DRMN6TP/K | 256 Kbit SPI EEPROM, 1.8–5.5 V, 20 MHz max clock, 8-lead SOIC, same pinout but higher speed and tighter tWC (4 ms typ). | Supports faster burst reads in high-throughput data loggers; lacks HOLD pin - requires software-managed transaction suspension. | Select when system clock exceeds 3 MHz and HOLD functionality is not required; verify timing margins for existing PCB layout. |
| BR25L256FJ-WE2 | 256 Kbit SPI EEPROM, 1.7–5.5 V, 10 MHz max clock, 8-lead SOP-J8, compatible pinout, integrated write protect latch. | Includes automatic write-enable latching - eliminates need for explicit WREN instruction before each write cycle. | Choose for simplified firmware integration where deterministic write sequencing is preferred over manual WREN management. |
Compared with M95256-DRMN6TP/K and BR25L256FJ-WE2, AT25256-10UI-1.8 offers unique HOLD pin support for seamless SPI pause/resume and finer-grained 1/4-array block protection - advantageous in multi-master bus arbitration and safety-critical parameter storage.
Availability
AT25256-10UI-1.8 is available at Aetrix Electronics and suitable for industrial sensor calibration storage, firmware parameter backup, embedded bootloader configuration, and secure key storage requiring stable component supply across extended temperature ranges.
Supply support for AT25256-10UI-1.8 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 technical and manufacturing continuity for the AT25xxx EEPROM family.
The AT25256-10UI-1.8 belongs to Microchip's industrial-grade serial EEPROM product line, designed specifically for reliable nonvolatile data storage in resource-constrained, low-power embedded systems operating across harsh environmental conditions.
FAQ
What is the maximum clock frequency supported by AT25256-10UI-1.8?
The AT25256-10UI-1.8 supports up to 3 MHz SCK frequency when operating within its 1.8 V to 3.6 V supply range. This value is characterized and tested per AC specifications in the datasheet; exceeding it may result in read/write failures or timing violations. The device remains fully compatible with slower SPI masters down to DC, making it suitable for ultra-low-power sleep-mode polling.
Does AT25256-10UI-1.8 require an external pull-up resistor on the SO pin?
No, AT25256-10UI-1.8 does not require an external pull-up on the SO pin. Its SO output is actively driven high or low during valid data transmission and enters high-impedance state when CS is high or HOLD is asserted. External pull-ups may cause bus contention or increased standby current and are explicitly discouraged in the datasheet recommendations.
How does the HOLD function behave during an active write cycle in AT25256-10UI-1.8?
The HOLD pin has no effect during an internal write cycle (tWC) in AT25256-10UI-1.8. Once CS transitions high to initiate programming, the device ignores HOLD until the write completes and returns to standby. HOLD is only functional during active SPI read/write transactions - i.e., while CS is low and SCK is toggling - allowing safe pausing of data streaming operations.
Can AT25256-10UI-1.8 be used with SPI Mode 1 (CPOL=0, CPHA=1)?
No, AT25256-10UI-1.8 only supports SPI Modes 0 (CPOL=0, CPHA=0) and 3 (CPOL=1, CPHA=1), as explicitly stated in the Features section. Attempting Mode 1 will result in misaligned sampling of SI/SO data due to incompatible clock phase and sampling edge timing - verified by AC timing parameter tSU/tH alignment requirements in the datasheet.
What happens if the WP pin is held low while WPEN = 0 in AT25256-10UI-1.8?
When WPEN = 0, the WP pin is disabled and has no effect on AT25256-10UI-1.8 operation - writes to unprotected memory and the status register proceed normally regardless of WP state. This design allows safe installation in systems where WP is hardwired to GND, while retaining full configurability of block protection bits via WRSR instructions.
AT25256-10UI-1.8 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-VFBGA
- Packaging:
- Tray
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- EEPROM
- Technology:
- EEPROM
- Memory Size:
- 256Kbit
- Memory Organization:
- 32K x 8
- Memory Interface:
- SPI
- Clock Frequency:
- 2.1 MHz
- Write Cycle Time - Word, Page:
- 10ms
- Access Time:
- -
- Voltage - Supply:
- 1.8V ~ 3.6V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-dBGA (5.21x3.4)
AT25256-10UI-1.8 FAQ
1.How can I place an order for AT25256-10UI-1.8 through Aetrix?
Please submit a Request for Quotation (RFQ) for AT25256-10UI-1.8 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 AT25256-10UI-1.8 reliable?
The price and inventory of AT25256-10UI-1.8 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT25256-10UI-1.8 is usually 5 days.
3.What payment methods are accepted for AT25256-10UI-1.8?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT25256-10UI-1.8 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT25256-10UI-1.8?
AT25256-10UI-1.8 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT25256-10UI-1.8 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 AT25256-10UI-1.8?
For technical support, including AT25256-10UI-1.8 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT25256-10UI-1.8 requirements.
6.How does Aetrix verify that AT25256-10UI-1.8 is sourced from the original manufacturer or authorized distributors?
All AT25256-10UI-1.8 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 AT25256-10UI-1.8 meets industry standards.
7.What is the process for return or replacement of AT25256-10UI-1.8?
All AT25256-10UI-1.8 units undergo pre-shipment inspection (PSI). If there is an issue with AT25256-10UI-1.8, 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 AT25256-10UI-1.8 part is unused and in its original packaging.
Return procedure for AT25256-10UI-1.8:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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