DAC63004: Set DAC63004 to a certain frequency

Nikollao Sulollari

Part Number: DAC63004

Tool/software:

Hi,

I am interested in the DAC63004 smart DAC. I have been reading the datasheet trying to figure out how to output a sine wave for a certain frequency. From what I understand there are hard coded slew rate options that allow you to set certain frequencies. My question is what if I want an output frequency that is not one of the pre-fixed frequencies? In the datasheet it says:

"An external RC load with a time constant larger than the slew-rate settings can be dominant over the internal frequency calculation."

Does this mean that I can add an external RC load to set the frequency I want?

over 1 year ago

0 Katlynne Jones over 1 year ago

TI__Mastermind 42013 points

Hi Nikollao,

No, this won't really work as you are intending to achieve a customer frequency. There will be a slight shift in phase as the output is charging a bit slower, but each code will still change at the specified time in the slew rate options which will result in the same output frequency. The main effect you would see is a smoothing in the code jumps:

Here's a TINA sim you can play around with. I replicated the code steps in the piecewise function of the signal generator:

SineWaveRCFilter.TSC

Best,

Katlynne Jones

0 Nikollao Sulollari over 1 year ago

Prodigy 20 points

OK, so I can only choose from a set of pre-fixed frequencies, I can't set any frequency I want within a range from e.g. 0 to 1 MHz?

0 Katlynne Jones over 1 year ago in reply to Nikollao Sulollari

TI__Mastermind 42013 points

Hi Nikollao,

Correct. You could choose to manually/continuously write the 24 DAC codes to the device to achieve your desired frequency, but the integrated feature will need to use one of the pre-fixed frequencies.

Best,

Katlynne Jones

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DAC63004: Set DAC63004 to a certain frequency