Amplitude Modulation using TTL or Urukul channel

nYadav

Is it possible to generate an amplitude modulation signal using either artiq TTL or Urukul channels, to control the output of a function generator?

han94ros

You can perform amplitude modulation using the Urukul boards depending on which DDS boards your system has as it is possible to set the DDS amplitude using AD9910 but not AD9912 boards. With the AD9910 there are two options, first to make use of the RAM to output a pre-calculated set of values however you are limited with a maximum ramp time of around 265ms given there are 1024 RAM samples and the maximum time between each sample is 265us. Otherwise you can ramp the amplitude by repeatedly calling the frequency and amplitude set function for the AD9910 in a loop. This would give you greater control over the total ramp time at the expense of increasing the overhead (reduction in slack).

enmdr

I would like to ask a question similar to this topic. I am using the AD9912 chip. Because the amplitude level of the chip's DDS output is high, spurs appear at the main frequencies. To eliminate this situation, I want to turn down the amplitude level of the DDS output. Can this be done, and if so how?

rjo

The 31.5 dB range digital step attenuator does that. In addition you can play with the full scale DAC current of the DDS by changing register values (see the AD9912 datasheet).