When we evaluted LTM9011 performance of Fin>300Mhz， the front End circuit as follows（recommended by datasheet） seems not work well. The adc's dynamic performance is poor. The SNR and SFDR can't meet spec.
We find 2.7nH seems the key point. If we short them, the performance is better. We think the TH circuit of ADC will sink or souce current from front end circuit, but the inductor can not support fast T/H action and reduce the T/H performnce, is it right?