Dear TI-
I am working with the ADS4249EVM and TWS1400. Both of these are in the stock/out-of-the-box configuration. I am observing larger than expected spurious in the FFT. Additionally, the codes view appears to have a pronounced AM envelope. I have attached a couple images from a specific scenario with the following setup;
100MSPS, +20 dBm+LPFx2
SOI 65 MHz, +20 dBm+10 dB pad +LPF+BPF
As you will see HD2 is ~43 dBc at 5 MHz. The AM envelope is also 5 MHz. We believe our clock and SOI sources (all 50-ohm) to be clean. HD3 appears close to datasheet level. Is it possible this is a result of mismatch in transformer parasitics? If I change sampling rate and SOI frequency, etc., I am still largely spur limited. Any insight is greatly appreciated
