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Microchip Technology AT17C256-10NI
- Part No.:
- AT17C256-10NI
- Manufacturer:
- Microchip Technology
- Category:
- Configuration PROMs for FPGAs
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
AT17C256-10NI.pdf
- Description:
- IC EEPROM FPGA 256KB 8-SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,112
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Product details
Overview
AT17C256-10NI from Microchip Technology (formerly Atmel) is a 256 Kbit (262,144 × 1-bit) serial EEPROM FPGA configuration memory operating at 5V ±10% over -40°C to +85°C industrial temperature range. It supports Master Serial Mode configuration of Xilinx, Altera, Lattice, and Atmel FPGAs via CLK/DATA interface, features programmable reset polarity, cascading CEO output, and low-power standby mode consuming ≤150 µA. Used in industrial embedded FPGA systems requiring reliable power-up configuration.
For engineers reviewing the AT17C256-10NI datasheet, AT17C256-10NI pinout, AT17C256-10NI application, or AT17C256-10NI equivalent, key selection factors include industrial-grade 5V operation, 20-lead PLCC/SOIC package compatibility, cascading support for multi-FPGA systems, SER_EN-controlled 2-wire programming mode, and write-protection via RESET/OE and WP functionality.
Technical Context
The AT17C256-10NI implements a serial-access EEPROM architecture optimized for FPGA configuration loading: it uses a synchronous master-slave protocol where FPGA CCLK drives the device's CLK input, and DATA output feeds FPGA DIN. Internal address counters auto-increment on each CLK edge during read cycles, with CEO assertion after final bit enables daisy-chained configuration of higher-density arrays.
It supports two distinct operational modes: normal configuration mode (SER_EN = High) and 2-wire serial programming mode (SER_EN = Low), with separate voltage requirements (5V only for AT17C variants). Reset polarity (active-High/active-Low) is user-programmable via EEPROM byte, eliminating external inverters in system reset integration.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 262,144 × 1-bit (256 Kbit) - sufficient to configure Xilinx XC4000 or Altera FLEX10K-class FPGAs in single-device mode. |
| Supply Voltage | 5V ±10% - supports industrial 4.5–5.5V rails without regulation; not compatible with 3.3V systems. |
| Operating Temperature | -40°C to +85°C - qualified for industrial environments including factory automation and motor control. |
| Max Clock Frequency | 12.5 MHz (standalone), 10 MHz (cascaded) - determines minimum configuration time; e.g., ~21 ms for full 256Kbit load at 12.5 MHz. |
| Standby Current | ≤150 µA - enables low-power hold state when CE = High, critical for energy-sensitive embedded systems. |
| Write Protection | Hardware-enabled via WP pin and programmable RESET/OE polarity - prevents accidental reconfiguration during system reset sequences. |
| Cascade Support | CEO output with 35–40 ns delay - allows chaining of multiple AT17C256-10NI devices to support >256Kbit FPGA configurations. |
Pinout & Package
AT17C256-10NI is available in 20-lead PLCC (20J) and 20-lead SOIC (20S) packages. Both share identical pin numbering and signal mapping per Atmel documentation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | DATA | Bi-directional open-collector I/O: outputs configuration bitstream to FPGA DIN; used as input during 2-wire programming. |
| 2 | CLK | Input clock synchronized to FPGA CCLK; increments internal address counter on rising edge during read mode. |
| 3 | (WP) RESET/OE | Multi-function input: active-Low reset/enable (polarity programmable); WP function disables writes to lowest memory block when CE = Low. |
| 4 | CE | Chip Enable input: Low enables data output and counting; High forces low-power standby (<150 µA) and halts internal logic. |
| 5 | GND | Ground reference; requires 0.2 µF decoupling capacitor adjacent to VCC pin for noise immunity. |
| 6 | CEO | Chip Enable Output: goes Low one cycle after last bit read; enables automatic cascade triggering of next EEPROM in chain. |
| 7 | SER_EN | Serial Enable input: High enables FPGA configuration mode; Low activates 2-wire programming interface (requires external programmer). |
| 8 | VCC | +5V power supply pin; must be stable within ±10% (4.5–5.5V) across industrial temperature range. |
| 9–13, 15–16, 18–20 | NC | No-connect pins - electrically isolated; must remain unconnected per design specification. |
Key Features
| Feature | Design Value |
|---|---|
| In-system programmable via 2-wire bus | Enables field firmware updates using standard programmers (e.g., ATDH2200E) without removing device from PCB. |
| Cascadable CEO output | Supports daisy-chain configuration of multiple AT17C256-10NI units for FPGAs requiring >256Kbit configuration data. |
| Programmable reset polarity | Eliminates need for external inverter by allowing active-High or active-Low reset behavior to match FPGA CON pin timing. |
| Emulation of AT24CXXX EEPROMs | Allows reuse of existing AT24Cxxx-based programming infrastructure and software tools for configuration memory provisioning. |
| Low-power CMOS EEPROM process | Ensures data retention >10 years and endurance >10,000 write cycles while maintaining industrial temperature stability. |
Applications
| Industrial PLC Configuration | Xilinx XC4000 FPGA Boot |
|---|---|
|
Use Scenario: Reconfigurable logic modules in programmable logic controllers require deterministic, repeatable boot from nonvolatile memory after power cycling or watchdog reset. IC Role / Device Role / Timing Role: AT17C256-10NI serves as master serial configuration memory, delivering bitstream to XC4000 DIN under CCLK control with CEO synchronization for multi-module expansion. Use Value: Industrial temperature rating (-40°C to +85°C) and 150 µA standby current ensure reliable operation in uncontrolled cabinet environments with minimal thermal derating. |
Use Scenario: Xilinx XC4000-series FPGAs load configuration on power-up in Master Serial Mode, requiring external serial PROM with precise timing alignment. IC Role / Device Role / Timing Role: AT17C256-10NI provides synchronized 12.5 MHz bitstream delivery with <55 ns CLK-to-DATA delay (TCAC), meeting XC4000 setup/hold requirements. Use Value: Pin-compatible PLCC/SOIC packaging simplifies board layout reuse across XC3000/XC4000 family designs without redesigning footprint or routing. |
| Altera FLEX10K Multi-Device Chain | Motor Drive FPGA Initialization |
|
Use Scenario: High-pin-count Altera FLEX10K FPGAs exceed 256Kbit configuration size, requiring cascaded EEPROMs to deliver full bitstream. IC Role / Device Role / Timing Role: AT17C256-10NI acts as first-stage configurator with CEO-driven enable of second AT17C256-10NI, supporting seamless >512Kbit load sequences. Use Value: Cascading AC specs (TOCK = 35–40 ns, TOCE = 35 ns) guarantee sub-100 ns inter-device handoff, preventing clock-domain misalignment in multi-chip chains. |
Use Scenario: Real-time motor control systems use FPGAs for PWM generation and encoder processing; configuration must complete before safety-critical startup sequence begins. IC Role / Device Role / Timing Role: AT17C256-10NI delivers deterministic boot time (~21 ms at 12.5 MHz) with programmable reset polarity to align with motor controller reset timing. Use Value: Write-protection via WP pin prevents unintended reprogramming during EMI-rich drive switching events, ensuring configuration integrity. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar FPGA configuration memory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT17LV256-10NI | 3.3V ±10% operation, lower max clock (10 MHz), higher AC delays (e.g., TCAC = 75–80 ns) | Targeted for 3.3V FPGA systems (e.g., Xilinx Spartan-II); incompatible with 5V-only designs | Select when host FPGA operates at 3.3V and industrial temp range is required; not drop-in replaceable due to voltage mismatch. |
| AT17C128-10NI | 128 Kbit density, same 5V/industrial spec, identical pinout and AC timing (except FMAX = 8 MHz when cascaded) | Suitable for smaller FPGAs (e.g., Xilinx XC3000, Altera MAX 7000); insufficient for XC4000/FLEX10K full config | Choose for cost-sensitive, lower-density FPGA applications where 128Kbit suffices; shares same footprint and layout. |
Compared with AT17LV256-10NI and AT17C128-10NI, the AT17C256-10NI uniquely delivers 256Kbit capacity at 5V with 12.5 MHz standalone speed-enabling single-chip configuration of mid-range FPGAs without voltage translation or density compromise.
Availability
AT17C256-10NI is available at Aetrix Electronics and suitable for industrial PLCs, motor drive controllers, and FPGA-based test equipment requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for AT17C256-10NI 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 EEPROMs, including manufacturing, documentation, and technical assistance.
The AT17 Series was designed specifically for reliable, low-complexity FPGA configuration in industrial and embedded systems-emphasizing pin compatibility, cascading scalability, and robustness across temperature and voltage variations.
FAQ
What is the maximum clock frequency supported by the AT17C256-10NI during FPGA configuration?
The AT17C256-10NI supports up to 12.5 MHz when operating in standalone mode, as specified in its AC characteristics table for commercial and industrial grades. In cascaded configurations, the maximum clock frequency reduces to 10 MHz to accommodate CEO propagation delays between devices. This timing ensures reliable bitstream delivery to FPGAs such as Xilinx XC4000 and Altera FLEX10K without setup/hold violations. The AT17C256-10NI must be operated within these limits to maintain functional integrity across its full -40°C to +85°C temperature range.
Does the AT17C256-10NI support 3.3V operation?
No, the AT17C256-10NI is a 5V-only device rated for 4.5V to 5.5V supply across industrial temperatures. It is not compatible with 3.3V systems. For 3.3V applications, the pin-compatible AT17LV256-10NI variant should be used instead. Attempting to operate the AT17C256-10NI at 3.3V will result in undefined behavior, failed configuration loads, and potential data corruption. The AT17C256-10NI's DC and AC specifications-including VIH/VIL thresholds and ICCA-assume nominal 5V operation.
How does the CEO pin function in a cascaded configuration with multiple AT17C256-10NI devices?
The CEO (Chip Enable Output) pin of the AT17C256-10NI asserts Low one clock cycle after the final bit is read, signaling the next AT17C256-10NI in the chain to enable its DATA output. This handoff occurs with a guaranteed 35–40 ns delay (TOCK) under industrial conditions. All cascaded AT17C256-10NI devices must share the same CCLK source, and CEO of stage N connects directly to CE of stage N+1. The AT17C256-10NI's CEO is not intended for standalone use-it functions exclusively in multi-device configuration chains.
Can the AT17C256-10NI be programmed in-circuit without removal from the PCB?
Yes, the AT17C256-10NI supports in-system programming via its 2-wire serial interface when SER_EN is driven Low. This mode allows industry-standard programmers (e.g., Atmel ATDH2200E) to reprogram the device while mounted on the target board. Programming occurs at VCC only-no external high-voltage supply is needed-as internal charge pumps generate required programming voltages. The AT17C256-10NI retains full functionality during normal operation (SER_EN = High), making field updates feasible without hardware intervention.
What package options are available for the AT17C256-10NI?
The AT17C256-10NI is offered in two surface-mount packages: 20-lead PLCC (20J) and 20-lead SOIC (20S), both compliant with industrial temperature range (-40°C to +85°C). These packages share identical pin numbering and electrical characteristics. The PLCC variant offers enhanced thermal dissipation and mechanical robustness for high-vibration environments, while the SOIC version supports higher board density. Neither PDIP nor 8-lead SOIC variants are available for the AT17C256-10NI-those are reserved for lower-density AT17C65/128 family members.
AT17C256-10NI 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:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
AT17C256-10NI FAQ
1.How can I place an order for AT17C256-10NI through Aetrix?
Please submit a Request for Quotation (RFQ) for AT17C256-10NI 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 AT17C256-10NI reliable?
The price and inventory of AT17C256-10NI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT17C256-10NI is usually 5 days.
3.What payment methods are accepted for AT17C256-10NI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT17C256-10NI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT17C256-10NI?
AT17C256-10NI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT17C256-10NI 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 AT17C256-10NI?
For technical support, including AT17C256-10NI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT17C256-10NI requirements.
6.How does Aetrix verify that AT17C256-10NI is sourced from the original manufacturer or authorized distributors?
All AT17C256-10NI 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 AT17C256-10NI meets industry standards.
7.What is the process for return or replacement of AT17C256-10NI?
All AT17C256-10NI units undergo pre-shipment inspection (PSI). If there is an issue with AT17C256-10NI, 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 AT17C256-10NI part is unused and in its original packaging.
Return procedure for AT17C256-10NI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AT17C256-10NI Tags
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EPCQ4ASI8N
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EPCQ64ASI16N
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EPCQ128ASI16N
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AT17LV512A-10JU
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AT17LV512-10JU
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AT17LV010-10JU
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