• Resolved

SN65C3222E: Absolute max

Genius 3110 points

Part Number: SN65C3222E

Dear Technical Support Team,

I have some questions about  "SN75C3222" and "SN65C1168EPWR".

These devices receive overshoot(nano sec) above abolute max on system.

If you have an information of actual value not to damage device, could you share it?

Off cource,  it is out of warranty.

For example, some logic ic has clamp diode, so it withstand vcc+1.0 until 10ns(absolute max is Vcc + 0.5V)

 

■Absolute max

SN65C3222E:VCC(MAX) = 6V

SN65C1167E:VCC(MAX) =7V

Best Regards,

ttd

  • Hello ttd,

    The amount of transient overshoot that can be tolerated beyond a device's absolute maximum specifications can be difficult to specify since the effect of the transient depends not just on its peak amplitude but its overall shape, duration, rise/fall times, etc. To get some idea of a device's performance, the best thing to do is to reference its ESD specifications (or any other transient immunity specifications that may be present).

    For example, SN65C3222E specifies immunity up to 8 kV for IEC 61000-4-2 contact discharge. This standard tests with a pulse that is about 100 ns wide and uses a coupling resistance of 330 Ohms (limiting the current that flows into the device). Based on this, you could expect that other transients that are lower in amplitude or duration would likely be OK as well. (The HBM ESD spec may be a useful data point as well.)

    If you would like, we could review a waveform capture of the overshoot to give more specific feedback.

    Max
  • Genius 3110 points

    In reply to Max Robertson:

    Hi max ,

    Thank you for your reply.

    Please see attached  file.

    waveform.pdf

    Best Regards,

    ttd 

  • In reply to ttd:

    ttd,

    Can you please set the oscilloscope so that it triggers at a level of ~7 V and then zoom in on the time scale so that the overvoltage transients can be captured in more detail? With the current time scale on the scope it isn't possible to see much of the waveform (each transient is only one pixel wide).

    Regards,
    Max