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voltage limiter and current feedback op amp

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EDA_hg81

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I am using current feedback op amp to realize voltage limiter.

why the output is only -10mv to -80mv?
 

FvM

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- The VSS supply has wrong polarity.
- +2/-3V is below AD8002 minimum supply voltage
- The supply voltage is too low to reach the zener voltage
- A current feedback OP requires a Rf resistor in a specified range around 1 k to set the loop gain. It doesn't allow e.g. limiting diodes or capacitors in parallel.
- Zener diodes don't work for high frequency limiters
 

    EDA_hg81

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EDA_hg81

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FVM,

Would you let me know how to design high frequency limiter?

Thank you.

Added after 40 minutes:

May I use the rail to rail power supply as voltage limiter since the output voltage only can rearch power supply.
if the power supply is +4V to to -4V, the output only can rearch +-4V.
 

vistapoint

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You may add a cap in parallel with R to form a 1st order low pass filter.

Your opamp usually has requirements on voltage supply. So using supply as limiters is not a good solution.

Low price resistors, capacitors, and LEDs: http://store.engeecorp.com

EDA_hg81 said:
FVM,

Would you let me know how to design high frequency limiter?

Thank you.

Added after 40 minutes:

May I use the rail to rail power supply as voltage limiter since the output voltage only can rearch power supply.
if the power supply is +4V to to -4V, the output only can rearch +-4V.
 

    EDA_hg81

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FvM

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You may not add a cap in parallel with R - in case of a current feedback OP.
 

    EDA_hg81

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aomidee

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to have a high frequency limiter,just replace two Zeners with one cap and use a lower resistance . but it wont feedback the current as good as your previous circuit! in this case, the feedback factor will vary with frequency, and you know that it is a filter! so, some parts of input signal wont be feedbacked! I think so but simulate it to reach certitude!
 

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EDA_hg81

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aomidee

Thank you so much and happy holiday!
 

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