AN 447: Interfacing Intel® FPGA Devices with 3.3/3.0/2.5 V LVTTL/LVCMOS I/O Systems

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ID 683295
Date 3/28/2022
Public
Document Table of Contents
Document Table of Contents x
Interfacing Intel® FPGA Devices with 3.3/3.0/2.5 V LVTTL/LVCMOS I/O Systems
Interfacing Intel® FPGA Devices with 3.3/3.0/2.5 V LVTTL/LVCMOS I/O Systems x
Receiver Level Requirements Guideline: Use Internal PCI Clamp Diode on the Pin Guideline: Use Series Termination Resistor Guideline: Select Appropriate Driver Interface Current between Supported Intel® Devices Document Revision History for AN 447: Interfacing Intel FPGA Devices with 3.3/3.0/2.5 V LVTTL/LVCMOS I/O Systems
Guideline: Use Internal PCI Clamp Diode on the Pin x
Measuring DC Current with PCI Clamp Diode
Guideline: Use Series Termination Resistor x
Selecting Appropriate Series Termination Resistor Value Example of Determining Series Termination Resistor Value
Guideline: Select Appropriate Driver x
Driver Selection Reference Current Limits Measurement Examples Evaluating Interface Using Driver Selection Method
Interfacing Intel® FPGA Devices with 3.3/3.0/2.5 V LVTTL/LVCMOS I/O Systems

Interfacing Intel® FPGA Devices with 3.3/3.0/2.5 V LVTTL/LVCMOS I/O Systems

Transmission line effects can cause a large voltage deviation at the receiver. This deviation can damage the input buffer, especially for I/O standards without termination, such as LVTTL or LVCMOS.

To manage signal integrity issues and protect the input pin, follow the guidelines in this document if you interface 3.3 V, 3.0 V, 2.5 V LVTTL or LVCMOS I/O systems with these Intel® device families:

  • Cyclone® III
  • Cyclone® IV
  • Intel® Cyclone® 10 LP
  • Intel® MAX® 10
Note: In this document, the term "supported Intel® devices" refers to devices in the listed device families only.

To ensure device reliability and proper operation, you must design the I/O interfaces within the specifications recommended by the guidelines in this document.

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