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Isolation b/w DAC & Power amplifier

masudasim

Aug 25, 2012
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Hello

i am using NI DAC (6723) to drive QSC RMX 4050HD Power amplifier (PA) having input impedance of 10 kohm. I am generating 1-5KHz sinusoidal signals from my DAC.

1- I need some isolation & signal smoothing b/w DAC & 2kWatt PA.

2- Secondly, NI DAC has current limitation of 5mA/channel. I also desire to boost this capacity to say (10mA/channel) with some IC b/w DAC output & PA input.


Can any one kindly suggest some type of analog isolation IC/transformer which can do this job?


Thanks

Best Regards
asim
 

CDRIVE

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May 8, 2012
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I just gotta know! What will you be doing with a 2KW sinewave?
 

CDRIVE

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Hello

i am using NI DAC (6723) to drive QSC RMX 4050HD Power amplifier (PA) having input impedance of 10 kohm. I am generating 1-5KHz sinusoidal signals from my DAC.

1- I need some isolation & signal smoothing b/w DAC & 2kWatt PA.

2- Secondly, NI DAC has current limitation of 5mA/channel. I also desire to boost this capacity to say (10mA/channel) with some IC b/w DAC output & PA input.


Can any one kindly suggest some type of analog isolation IC/transformer which can do this job?


Thanks


Best Regards
asim

I don't get any of this. If the input Z of your amp is 10KΩ it would require an input voltage of 100V to draw 10mA! :eek:
 

BobK

Jan 5, 2010
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I just gotta ask: what does a smoothed sine wave look like?

edited: never mind, I see that it is a DAC output, so smoothing (usually know as filtering) does make sense.

Bob
 

CDRIVE

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Hello

i am using NI DAC (6723) to drive QSC RMX 4050HD Power amplifier (PA) having input impedance of 10 kohm. I am generating 1-5KHz sinusoidal signals from my DAC.
Thanks

Best Regards
asim

I need to drive a acoustic transducer with this voltage

According to this the PA is driving the acoustic transducer. Your DAC needs to drive the 10KΩ input to the PA. You need a HiZ (>=1MΩ) input to an OpAmp to properly interface a DAC output.

Chris
 
Last edited:

Merlin3189

Aug 4, 2011
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Not a comment - I just wonder what " b/w " means in this context.

.... isolation & signal smoothing b/w DAC & 2kWatt PA.
.... with some IC b/w DAC output & PA input.

I can't see how "bandwidth" or "black and white" would fit, so I wonder if there's another meaning I should know?
 

masudasim

Aug 25, 2012
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Dear
Thanks for reply

"According to this the PA is driving the acoustic transducer. Your DAC needs to drive the 10KΩ input to the PA. You need a HiZ (>=1MΩ) input to an OpAmp to properly interface a DAC output"

Yes, Opamp with input impedance >1Mohm are easily available but problem is that i will not get isolation by using it b/w DAC and PA input
 

Harald Kapp

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An audio transformer helps, see my first answer.
 

CDRIVE

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As Harold said, you can use a small audio transformer. You'd connect it between the OpAmp output and the PA input.

Curious though.. Why do you need isolation?

Chris
 
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