SBAS480C september 2009 – june 2023 ADS1000-Q1
PRODUCTION DATA
The ADS1000-Q1 uses a switched-capacitor input stage. To external circuitry, this stage functions roughly like a resistance. The resistance value depends on the capacitor values and the rate at which the values are switched. The switching clock is generated by the onboard clock generator, so the frequency, nominally 275 kHz, is dependent on supply voltage and temperature. The capacitor values depend on the PGA setting.
The common-mode and differential input impedances are different. For a gain setting of PGA, the differential input impedance is typically 2.4 MΩ / PGA. The common-mode input impedance is typically 8 MΩ.