Result differ. from the simulation (ne5534)

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zefiris2K5

New Member

• Jan 2, 2006

• #1

Hello everybody,
I'm new in this field and I will try as hard as I can to love this field.
And, for the question is why the result from the real world different from the simulation. Currently, I experimenting an negative feedback OP-Amp using ne5534. I've follow the schematic and assign the Cc = 47pf, 22pF, 0pF (according to the datasheet). None of the configuration show the result of amplification (including the inverted signal).

 

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audioguru

Well-Known Member

Most Helpful Member

• Jan 2, 2006

• #2

It looks like you forgot to add negative feedback and an input voltage reference.

 

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• ne5534.png

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Z

zefiris2K5

New Member

• Jan 2, 2006

• #3

I have do that.....just forgot to include....

 

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• ne5534_simulation.png

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audioguru

Well-Known Member

Most Helpful Member

• Jan 2, 2006

• #4

Your schematic has a gain of only 2. The NE5534 will oscillate without a compensation capacitor for a gain less than 3.
The value of your offset adjustment pot is 5 times too high.
What is your tested result and what is your simulated result?

 

Z

zefiris2K5

New Member

• Jan 3, 2006

• #5

The result of ne5534 from ti:
o/p = 72mV without invert signal

and the result of ne5534 from phillips:
o/p = 480mV without invert signal

Also, I have tested configuration of gain = 22(r4=1k,r5=22k) and the result quite same.

 

Z

zefiris2K5

New Member

• Jan 3, 2006

• #6

forgot to mention that I've also put the Cc with the value 47pf, 22pf and 0pf

 

audioguru

Well-Known Member

Most Helpful Member

• Jan 3, 2006

• #7

Adjust the offset voltage pot. That's what it is there for.

 

Z

zefiris2K5

New Member

• Jan 3, 2006

• #8

Anyway...I've solved the problem. Looks like my ne5534 has burned. The result from the experiment as expected. Thanks for the help...... :wink: