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Methods for TTL line protection

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rellutzu

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Hello all!
I am currently working on a protection circuit for a pxi interface and I need
an under/overvoltge protection circuit for ttl Dio lines.

I am open to suggestions/comments or links toward related application notes!

Best regards!
 

Kral

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Re: TTL line protection

rellutzu,
A common methode is to do the following:
Connect a Schottky diode from input to ground (Anode Goes to Ground). This protects from negative transients
~
Connnect a Schottky diode from input to Vcc (Cathode goes to Vcc). This protects from positive transients.
Regards,
Kral
 

archiees

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Re: TTL line protection

Hi,
What about using the opto-isolators? Have you thought about them.
 

IanP

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Re: TTL line protection

Optoisolators are another very efficient way of protecting digital (not only TTL)inputs ..
They are commonly used in industrial applications as the most reliable protection providing not only galvanic isolation between both sides (no ground loop problems) but overvoltage and overcurrent protection, too ..

Some hints on how to use them can be found here:
https://www.ee.ttu.edu/lab/robot/opto.htm

Regards,
IanP
 

ferrite

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Re: TTL line protection

i am wondering whether this can be done on an IC?

archiees said:
Hi,
What about using the opto-isolators? Have you thought about them.
 

mengghee

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Re: TTL line protection

Hello,

I don't think that opto isolation can be done with a single chip. the circuit for it is rather simple. i am not sure though.

hope it helps.

regards,
mengghee
 

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