SBAS350G June 2005 – January 2021 ADS1232 , ADS1234
PRODUCTION DATA
By applying a 0.1-µF external capacitor (CEXT) across two PGA output pins (pins 9 and 10) and the combination of the internal 2-kΩ resistor (RINT), a low-pass filter, with a corner frequency of 720 Hz, is created to band limit the signal path prior to the modulator input. This low-pass filter serves two purposes. First, the input signal is band-limited to prevent aliasing, as well as to filter high-frequency noise. Second, the low-pass filter attenuates the chopping residue from the PGA (for gains of 64 and 128 only) to improve temperature drift performance. High-quality capacitors (such as high-k ceramic or tantalum capacitors) are not required for a general application. However, high-quality capacitors, such as C0G dielectric ceramic or poly, are recommended for high-linearity applications.