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output resistance and outptu capacitance of DAC

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nathanee

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Hi, there,

There are 2 DC accuracy spec in digital to analog converter datasheet.
Take TI, DAC900 for example.
1. output resistance = 200k ohm.
2. output capacitance = 12pF.

My questions are,
1. how to simulate these spec?
2. which performance parameters the output capacitance/resistance will influence?

BR,
-nathanee
 

paulux

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You may try to inject ac signal at the output of DAC and measure the current, then you would get the equivalent resistance. Try different freq. of ac signal, the equivalent capacitance may be found. The output R & C could influence any ac output signal because the R & C could be a parasitic low-passs filter on the output. Other opinions/comments are highly welcomed.
 

nathanee

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The method by using ac signal and sweep frequency is to measure AC response of DAC output.
But, the datasheet spec is DC-ACCURACY, instead of AC. This make me confused.

Any opinion/suggestion is welcomed.

BR,
-nathanee
 

paulux

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Similar to ac signal injection technique,
you can inject/sink different DC current into the output node to see if there is any voltage on the output node.
 

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