voltage limiter and current feedback op amp

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EDA_hg81

Joined: 25 Nov 2005
Posts: 395

20 Oct 2009 3:24 voltage limiter and current feedback op amp

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

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

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FvM

Joined: 22 Jan 2008
Posts: 5160
Helped: 767
Location: Bochum, Germany

20 Oct 2009 8:17 Re: voltage limiter and current feedback op amp

- 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

Joined: 25 Nov 2005
Posts: 395

21 Oct 2009 1:05 Re: voltage limiter and current feedback op amp

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

Joined: 20 Feb 2005
Posts: 91
Helped: 2

04 Nov 2009 15:59 Re: voltage limiter and current feedback op amp

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.

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EDA_hg81 wrote: