ZHCSES1B March 2016 – October 2018 ADS1282-SP
PRODUCTION DATA.
The modulator samples the buffered input voltage with an internal capacitor to perform conversions. The charging of the input sampling capacitor draws a transient current from the PGA output. The average value of the current can be used to calculate an effective input impedance of:
where
The resulting modulator input impedance for CLK = 4.096 MHz is 55 kΩ. The modulator input impedance and the PGA output resistors result in a systematic gain error of –1%. CS can vary ±20% over production lots, affecting the gain error.