DAC38RF80: INTEGRATED balun frequency range

Hi Lalit,

One of our experts is looking into this question, and will be back with you soon.

Best Regards,

Dan

Lalit,

In your case, you would use a DAC38RF82, which does not have an internal balun. With this part you can use whatever balun or transformer you like. That is the only difference between these two parts.

Regards,

Jim

Hi Jim,

Thanks for the quick reply.

Does it mean that we can't generate frequencies which not lie in the range 700Mhz-3800Mhz or if we try to generate frequencies outside of the DAC internal balun the output signal will have distortion?

Thanks,

lalit

Lalit,

I am looking into finding more info regarding the internal balun on this part. I did some tests by varying the frequency and recording the output power on a DAC38RF80EVM. Here are the results:

Frequency (MHz)             Power (dBm)

300                                         -9.57

400                                         -7.88

500                                         -7.03

600                                         -6.45

700                                         -6.0

800                                         -5.7

3800                                       -11.2

3900                                       -11.7

4000                                       -12.5

4100                                       -13.0

4200                                       -13.5

4500                                       -14.5

I did not see any sign of signal distortion.

Regards,

Jim

Hi Jim,

Thanks for this useful information.

But this data doesn't match with the graph which is given in datasheet.

Let say for example at 500MHz, output power given in datasheet is around -1dBm but according to the tests which you have performed shows power of -7.03dBm at 500Mhz.

And there is a difference in power in datasheet and your test result across the entire frequency range.

Why there is so much difference in power level between what the datasheet says and your test results?

Thanks,

Lalit

Hi Jim, 

I hope you are doing good.

Sorry for the late reply but I have one more query and the answer to this query will decide whether we need to go with DAC38RF80 or DAC38RF82.

Our customer needs to generate the following signal frequencies from DAC:

1. 70 Mhz

2. 2.7Ghz

So ,can you please generate these two signal frequencies from DAC38RF80EVM(with integrated balun) in your lab and measure the output power(with mixer gain enabled) from DAC38RF80 and post here as you have done previously?

An early response will be highly appreciated.

Thanks,

Lalit