Part Number: ADS9218 Tool/software: Hello! I'm using the ADS921x family (specifically ADS9218) in a design. In this design we have a large number of ADCs and for simplicity / to lower cost we'd like to run them all off of the same precision external reference. However, at the recommended REFIO pin capacitance of 10uF the total load capacitance is too much for our external reference. Would it be possible to reduce the REFIO pin capacitance to the ~1uF-2.2uF range without impacting performance? If not what is the minimum capacitance for that pin before performance is impacted and are there any metrics you can provide to help determine what an acceptable REFIO pin capacitance would be (i.e. freq content of external reference rail must be < X dB across Y BW, etc...) The ADS9218 datasheet doesn't seem to provide any information about the REFIO pin to inform this other than the 10uF recommendation and figures showing steering diodes & the PD_REF switch.
↧