Forum Post: ADC128S102: ADC128S102 input impedance

Part Number: ADC128S102 Tool/software: hello We want to know if ADC128S102 is a high impedance input and whether a follower needs to be added to the analog input. the reference design of TI has add a follower,But he can also choose not to add, I ask when to add and when not to add In addition, VA can be used as an internal reference voltage. According to the reference design, an LDO has been added here. Is it possible to use DCDC Look forward to your reply。