ZHCSIJ5C August 2018 – June 2019 ADS9224R , ADS9234R
PRODUCTION DATA.
On the CONVST rising edge, both converters start converting the sampled value on the analog input, and the internal capacitors are switched to the REFP_x pins. Most of the switching charge required during the conversion process is provided by the external decoupling capacitor CREFP_x. If the charge lost from CREFP_x is not replenished before the next CONVST rising edge, the subsequent conversion occurs with this different reference voltage and causes a proportional error in the output code. To eliminate these errors, the internal reference buffers of the device maintains the voltage on the REFP_x pins. The reference buffers have a gain of GREFBUF, as specified in the Specifications section. The voltage at the REFP_x pins can be calculated as VREFP_x = GREFBUF × VREFOUT.