how to get lab view to display my plot in DB

[emeho]

hi guys

i desigED n an operational amplifier to determine the gain product band width using a 741 chip and the gain of the circuit is 1000, meaning that the gain bandwidth PRODUCT  will occur at a frequency of 100hz. but i have a problem, when i start the frequency sweep from the function generator from 10 hz to 100Khz which  IS the final frequency value i have set for the program. when the lab view program stops and i export the data to excel sheet i will be getting the DB axis value in a SMALL VALUES AND IN DIFFERENT  UNITES  WHEN I PLOT THE GRAPH USING EXCEL,  while the frequency is in log10.

       pls can any one tell me how to solve this problem to start getting the right cut off  frquency on the graph. find aattched my vi and the excel data from the vi that is in a different unit not in DB

[JÞB]

In a thousand words

[emeho]

thanks Jeff Bohrer  for your reply, what i mean is the y-axs of the plot is in DB aleady, but when i export the data to excel i will be seeing the gain in 0.8, 0.7,0.4 which is not normal,  which will not give me the -3db point of the gainband width product of the circuit

[JÞB]

Ahhh.....

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@emeho wrote:

thanks Jeff Bohrer  for your reply, what i mean is the y-axs of the plot is in DB aleady, but when i export the data to excel i will be seeing the gain in 0.8, 0.7,0.4 which is not normal,  which will not give me the -3db point of the gainband width product of the circuit

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What you want to do is plot the Log(10) of the frequency on a linear axis!!!!!!!  The export - exports the values not the axis scale.  exporting a log(10) of the Y axis will export the log of the axis- (of couse, you could change the graph axis scale in Excel too...... but)