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Microchip Technology AT17C256-10NC
- Part No.:
- AT17C256-10NC
- Manufacturer:
- Microchip Technology
- Category:
- Configuration PROMs for FPGAs
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
AT17C256-10NC.pdf
- Description:
- IC EEPROM FPGA 256KB 8-SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,767
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Product details
Overview
AT17C256-10NC from Microchip Technology (formerly Atmel) is a 256 Kbit (262,144 × 1-bit) serial EEPROM FPGA configuration memory designed for master-serial mode loading of Xilinx XC3000/XC4000/XC5200/SPARTAN, Altera FLEX®, Lucent ORCA®, and Atmel AT40K/AT6000 FPGAs. It operates at 5V ±5%, supports programmable reset polarity, and delivers 12.5 MHz max clock frequency in non-cascaded mode.
For engineers reviewing the AT17C256-10NC datasheet, AT17C256-10NC pinout, AT17C256-10NC application, or AT17C256-10NC equivalent, key selection criteria include cascading capability via CEO output, 2-wire in-system programmability, write-protection control via WP input, low-power standby current (≤75 µA), and compatibility with commercial temperature range (0°C to +70°C).
Technical Context
The AT17C256-10NC implements a serial-access configuration memory architecture optimized for synchronous bitstream loading into SRAM-based FPGAs. Its internal address counter advances on CLK edges, and data is driven on DATA during active CE/OE conditions. The device supports two distinct reset configurations-active-high or active-low-via programmable EEPROM byte.
Cascading is enabled only on AT17C128/256 variants using the CEO output to chain multiple devices; AT17C256-10NC asserts CEO low after its final bit, enabling the next device's DATA output. SER_EN must be held high during FPGA configuration and pulled low only during 2-wire ISP programming.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory size | 262,144 × 1-bit (256 Kbit) nonvolatile EEPROM storage for full FPGA bitstream |
| Supply voltage | 5V ±5% - ensures compatibility with legacy 5V FPGA systems and avoids level-shifting |
| Max clock frequency | 12.5 MHz - enables fast configuration load times (~21 ms for full 256Kbit at 12.5 MHz) |
| Standby current | ≤75 µA at 5V - minimizes system power during FPGA idle or hold states |
| Operating temperature | 0°C to +70°C - qualified for commercial-grade embedded and industrial control applications |
| Cascade support | CEO output enables daisy-chain configuration of multiple FPGAs or higher-density arrays |
| Reset polarity | Programmable active-high or active-low - eliminates need for external inverters in diverse reset architectures |
Pinout & Package
AT17C256-10NC is available in 20-lead PLCC (20J), 20-lead SOIC (20S), 8-pin PDIP (8P3), and 8-lead SOIC (8S1) packages. The -10NC suffix denotes 20-lead PLCC package with commercial temperature grade.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| DATA | I/O | Three-state open-collector bidirectional data line - drives FPGA DIN during configuration; used for 2-wire programming |
| CLK | Input | FPGA CCLK-synchronized clock input - increments internal address/bit counter on rising edge |
| RESET/OE | Input | Programmable reset/output enable - resets address counter when asserted; polarity configurable in EEPROM |
| CE | Input | Chip enable - disables counters and forces standby mode when high; enables data output when low with OE |
| GND | Power | Ground reference - requires 0.2 µF decoupling capacitor near VCC pin per datasheet recommendation |
| CEO (A2) | Output | Chip enable output - goes low after last bit read to enable next cascaded AT17C/LV128/256 device |
| SER_EN | Input | Serial enable - must be high during FPGA configuration; pulled low to enter 2-wire ISP programming mode |
| VCC | Power | +5V supply pin - powers EEPROM core and I/O buffers; supports 5V ±5% tolerance |
Key Features
| Feature | Design Value |
|---|---|
| In-system programmability | 2-wire serial interface (SER_EN low) enables field reprogramming without socket removal or dedicated programmers |
| Cascadable configuration | CEO output allows chaining up to multiple AT17C256-10NC devices to support larger FPGA bitstreams or multi-FPGA systems |
| Write protection control | WP input disables writes to lowest memory block when high - prevents accidental corruption of boot code or critical configuration segments |
| SRAM FPGA interface simplicity | Direct connection to Xilinx/Altera/Lucent/Atmel FPGA master-serial pins - no glue logic or timing compensation required |
| Emulation of AT24CXXX | Compatible with standard I²C EEPROM protocols - simplifies integration into existing programmer infrastructure and test fixtures |
Applications
| Industrial PLC Configuration | Xilinx SPARTAN FPGA Boot |
|---|---|
Use Scenario: Reconfigurable logic in factory automation controllers requiring field-upgradable firmware without hardware replacement. IC Role / Device Role / Timing Role: Stores and serially delivers full bitstream to Xilinx SPARTAN FPGA on power-up or command, synchronized to CCLK. Use Value: Enables zero-downtime firmware updates via ISP; CEO chaining supports dual-FPGA redundancy architectures. | Use Scenario: Boot-time configuration of Xilinx SPARTAN-3/6 FPGAs in telecom line cards where reliability and fast startup are critical. IC Role / Device Role / Timing Role: Acts as master-serial configuration memory, driving DIN under CCLK control with deterministic 12.5 MHz load timing. Use Value: Eliminates external configuration controllers; programmable reset polarity matches diverse board-level reset schemes. |
| Altera FLEX® System Initialization | Multi-FPGA Test Fixture |
Use Scenario: Lab validation of Altera FLEX 10K/8000 series FPGAs where configuration persistence across power cycles is mandatory. IC Role / Device Role / Timing Role: Provides nonvolatile storage for configuration data; interfaces directly to CON and CCLK pins per Altera master-serial spec. Use Value: Reduces test setup complexity - no JTAG configuration needed for basic functional verification. | Use Scenario: Automated test platform for evaluating FPGA interconnect integrity across multiple devices simultaneously. IC Role / Device Role / Timing Role: Cascaded AT17C256-10NC units deliver coordinated bitstreams to each FPGA in sequence via CEO handoff. Use Value: Scales configuration memory capacity beyond single-device limits while maintaining timing alignment across DUTs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar FPGA configuration memory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT17LV256-10NC | 3.3V operation (3.0–3.6V), lower ICCA (5 mA), reduced FMAX (10 MHz), same pinout and functionality | Required for 3.3V FPGA systems; not suitable for 5V-only designs without level translation | Select when target FPGA uses 3.3V I/O banks and power budget constraints favor lower active current |
| XCR3256XL-10TQ144I | Integrated CPLD with onboard configuration memory - no external EEPROM needed; different architecture and programming model | Replaces discrete configuration memory with embedded solution; requires redesign of configuration interface logic | Choose only if migrating to Xilinx CoolRunner-II CPLD platform and accepting architectural change |
Compared with AT17LV256-10NC, AT17C256-10NC provides higher clock speed and 5V compatibility but consumes more active current; versus XCR3256XL-10TQ144I, it offers drop-in replacement for legacy EEPROM-based FPGA designs without FPGA logic redesign.
Availability
AT17C256-10NC is available at Aetrix Electronics and suitable for industrial PLCs, telecom line cards, FPGA-based test equipment, and embedded control systems requiring stable component supply across extended product lifecycles.
Supply support for AT17C256-10NC 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 support for legacy Atmel FPGA configuration products including the AT17 series.
The AT17C/LV family was designed specifically to provide cost-effective, serial, nonvolatile configuration memory for SRAM-based FPGAs from Xilinx, Altera, Lucent, and Atmel - emphasizing ease of interface, in-system programmability, and cascade scalability.
FAQ
What is the function of the CEO pin on the AT17C256-10NC?
The CEO (Chip Enable Output) pin on the AT17C256-10NC goes low one clock cycle after the final bit is read, signaling the end of its configuration data stream. This enables cascading by asserting CE on the next AT17C/LV128/256 device in the chain. CEO remains low while CE and OE are both low, then follows CE state until OE goes high. In standalone use, CEO is unused but must be left unconnected or terminated per layout guidelines.
Can the AT17C256-10NC be used with 3.3V FPGAs?
No - the AT17C256-10NC is a 5V-only device (4.75–5.25V for commercial grade) and is not electrically compatible with 3.3V FPGA I/O standards. For 3.3V systems, use the pin-compatible AT17LV256-10NC variant, which operates at 3.0–3.6V and maintains identical functionality, pinout, and timing architecture except for reduced maximum clock frequency (10 MHz vs. 12.5 MHz).
How does the RESET/OE pin work on the AT17C256-10NC?
The RESET/OE pin on the AT17C256-10NC serves dual functions: as an output enable (OE) to activate the DATA driver when CE is low, and as a reset input to clear the internal address and bit counters. Its active polarity (high or low) is programmable via an EEPROM byte, eliminating the need for external inverters. During configuration, it is typically driven by the FPGA's CON pin or dedicated reset net depending on system-level reset requirements.
Is the AT17C256-10NC compatible with Xilinx XC7 series FPGAs?
No - the AT17C256-10NC is explicitly designed for legacy Xilinx families including XC3000, XC4000, XC5200, and SPARTAN (pre-SPARTAN-3). Xilinx 7-series FPGAs require different configuration modes (e.g., SelectMAP, JTAG, or QSPI) and are incompatible with the AT17C256-10NC's master-serial protocol and timing. Use Xilinx-approved configuration solutions such as Platform Flash or Micron QSPI NOR for XC7 devices.
What packaging options are available for the AT17C256-10NC?
The AT17C256-10NC is offered exclusively in the 20-lead PLCC (Plastic Leaded Chip Carrier) package, as indicated by the "NC" suffix per Atmel's ordering guide. Other variants like AT17C256-10PC (PDIP), AT17C256-10SC (SOIC), and AT17C256-10JC (PLCC industrial grade) exist but differ in package type or temperature rating - the -10NC designation uniquely identifies the commercial-grade 20J PLCC version.
AT17C256-10NC Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Programmable Type:
- Serial EEPROM
- Memory Size:
- 256Kb
- Voltage - Supply:
- 4.75V ~ 5.25V
- Operating Temperature:
- 0°C ~ 70°C
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
AT17C256-10NC FAQ
1.How can I place an order for AT17C256-10NC through Aetrix?
Please submit a Request for Quotation (RFQ) for AT17C256-10NC 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 AT17C256-10NC reliable?
The price and inventory of AT17C256-10NC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT17C256-10NC is usually 5 days.
3.What payment methods are accepted for AT17C256-10NC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT17C256-10NC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT17C256-10NC?
AT17C256-10NC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT17C256-10NC 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 AT17C256-10NC?
For technical support, including AT17C256-10NC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT17C256-10NC requirements.
6.How does Aetrix verify that AT17C256-10NC is sourced from the original manufacturer or authorized distributors?
All AT17C256-10NC 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 AT17C256-10NC meets industry standards.
7.What is the process for return or replacement of AT17C256-10NC?
All AT17C256-10NC units undergo pre-shipment inspection (PSI). If there is an issue with AT17C256-10NC, 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 AT17C256-10NC part is unused and in its original packaging.
Return procedure for AT17C256-10NC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AT17C256-10NC Tags
-
AT17LV512A-10PU
Microchip Technology
-
EPCQ4ASI8N
Intel
-
AT17LV256-10PU
Microchip Technology
-
AT17LV256-10NU
Microchip Technology
-
EPCQ16ASI8N
Intel
-
AT17LV010-10PU
Microchip Technology
-
EPCQ32ASI8N
Intel
-
EPCQ64ASI16N
Intel
-
EPCQ128ASI16N
Intel
-
AT17LV512A-10JU
Microchip Technology
-
AT17LV512-10JU
Microchip Technology
-
AT17LV010-10JU
Microchip Technology
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