I've seen the term SpurKiller applied to some of your parts,what does that refer to and how can I use it?
The term Spurkiller refers to a subset of the ADI portfolio which has incorporated additional DDS channels within the same package which can be mixed together in the digital domain to create destructive interference. The goal is to enable users to reduce the magnitude of the largest spurs in their output spectrum. The first two devices on which the technology was developed are the AD9911 and AD9912. There are numerous limitations, but this is one avenue worth exploring if good SFDR is vital for you.
The concept is fairly straightforward. Use an auxiliary DDS channel to create a signal that is the same frequency and magnitude as your troublesome spur, but make it 180 degrees out of phase with that spur.
Specifically, here are some limitations:
1) If the spur is already low in magnitude, it may not be possible to take it any lower. Generally, spurs less than -60 dBc get hard to impact
2) The spur pretty much needs to be a harmonic in order to hit the frequency precisely, which is vital
3) Process and temperature vairations will impact the phase and amplitude of the spur. In an uncontrolled environment without feedback, you cannot adjust the spurkiller channel phase and magnitude to compensate for those factors, so the amount of reduction that can be acheived is reduced.
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