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arulmaniv's avatar
arulmaniv
Icon for New Contributor rankNew Contributor
10 months ago

Cyclone V Clamping Diode Electrical Specification

Hi,

Please provide the below information for the Cyclone V Device IO Banks signals.

  1. what is the clamping voltage for the internal diode when enabled.
  2. what is the normal protection voltage for IO pin when clamping diode is not enabled.
  3. What is the diode used for an Clamping diode, is it an Zenor Diode or TVS Diode or Schottky Diode

 

Configuration
Generic Io
quality|reliability

6 Replies

  • FvM's avatar
    FvM
    Icon for Super Contributor rankSuper Contributor
    9 months ago

    Hi,

    did you see IO element schematic in device handbook? It shows clamping diode as silicon diode against VCCIO.

    Most detailed specification of IO voltage characteristic can be found in IBIS files.

    Not sure what you mean with "normal protection voltage". Did you review maximum ratings in datasheet?

     

    • arulmaniv's avatar
      arulmaniv
      Icon for New Contributor rankNew Contributor
      9 months ago

      We are currently reviewing the protection mechanisms for the Cyclone V device and would appreciate your assistance in clarifying the following details regarding the internal clamping diode configuration:

      1. Clamping Voltage (when enabled):
        Could you please confirm the clamping voltage level for the internal diode when it is enabled on the IO pins?
      2. IO Pin Protection Voltage (when clamping diode is disabled):
        What is the typical protection voltage range for the IO pins when the internal clamping diode is not enabled?

      This information is critical for ensuring compliance with our system-level ESD and surge protection requirements. We would appreciate any documentation or references you could share to support these specifications.

      Thank you in advance for your support.

      • AqidAyman_Altera's avatar
        AqidAyman_Altera
        Icon for Regular Contributor rankRegular Contributor
        9 months ago

        Hi,

        Please download the IBIS model for Cyclone V using the link below:

        https://www.altera.com/design/devices/resources/models/ibis

        Consulting the official Cyclone V IBIS files is a reliable method to understand the internal diode clamping voltage and IO pin protection at a detailed electrical level. For precise numerical values or simulation, use the IBIS files along with signal integrity simulation tools.

        Thanks.