SN65C1167E / countermeasure of the impedance mismatching

Ryuji

Guru 20090 points

Other Parts Discussed in Thread: SN65C1167E

Hello,

Our customer uses SN65C1167E.
Since they must connect the SN65C1167E to some components, they can't manage Impedance...

Please see the attached waveform as result of this impedance mismatching.

4237.SN65C1167E.pdf

Output voltage is increased by reflection of the signal.
Absolute maximum ratings of the output pin is 7V.
Thus, we must consider the protection method for Vout pin.

(1)
Could you please kindly let me know any good method ?

(2)
We consider putting the clamp diode for the protection.
Are there any problem on this method ?

If there is no problem, please let me know P/N of the Diode for my reference...

Best Regards,
Ryuji Asaka

over 11 years ago

0 John Griffith over 11 years ago

TI__Mastermind 21841 points

Hi Asaka-san,

Would the customer be willing to share their schematic? I am concerned whatever they are doing will cause signal integrity issues as well?

In terms of your questions, adding protection components like transient voltage suppressors, will help clamp the voltage and protect the device from being damaged. I have used the MMBZxx family of voltage suppressors from On-Semi and have had good results with them. I have attached the datasheet for the family of devices, please let me know if you have any questions.

Thanks,

John

0 John Griffith over 11 years ago in reply to John Griffith

TI__Mastermind 21841 points

Sorry, I forgot to attach the datasheet. The family comes with a series of diodes with different breakdown voltages.

Thanks,

John

MMBZxxxALT1G_Series.pdf

0 Ryuji over 11 years ago in reply to John Griffith

Guru 20090 points

Hello John san,

Thank you very much for your prompt reply.

I will check the schematics to our custmer.

And inform the On-semi's suppressors to our customer.

Best Regards,

Ryuji Asaka

0 Ryuji over 11 years ago in reply to Ryuji

Guru 20090 points

Hello John san,

I got the schematics.

However, since the schematics is customer's confidential , I sent it to you directly by e-mail.

Please kindly check and give me advice.

Best Regards,

Ryuji Asaka

0 John Griffith over 11 years ago in reply to Ryuji

TI__Mastermind 21841 points

Asaka-san,

I have responded to your email directly with my feedback from the schematic you shared.

Thanks,

John

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SN65C1167E / countermeasure of the impedance mismatching