DDS with 47-bit tuneable frequency word.
We got a 350 eur AIM-TTi TF930 frequency counter for less demanding frequency counting. Here's how it looks like on the inside.
See also discussion on the AD forum: https://ez.analog.com/dds/f/q-a/107510/ad9912-ftw-lsb-always-zero
We've tried to measure the frequency resolution of the AD9912 DDS, which when used with a 1 GHz SYSCLK should be 1 GHz / 2**48 = 3.55 uHz.
In both cases the output frequency corresponds to an even frequency tuning word (FTW) although we step the frequency by one LSB. In other words the LSB appears to be zero in all cases, even when we write an odd FTW with '1' as the LSB. Instead of the expected 3.55 uHz frequency resolution we see double-sized steps of 7.1 uHz.
The Urukul measurement was done with a Microsemi 3120A phase-meter and the dev-board was measured using a PICDIV 1PPS-divider followed by a Keysight 53230A time interval counter. The even FTW frequencies agree with the predicted frequency to much better than 0.1 uHz.
Have been using this SMD heatsink for (among others) TO-263 voltage regulators, e.g. LT1963 and LT3015.
These 'plain' footprints correspond to the "land-pattern" footprints created previously. No GND-pads or GND-vias in these.