SBAS949A February 2020 – February 2021 ADS131M06
For best performance, dedicate an entire PCB layer to a ground plane and do not route any other signal traces on this layer. However, depending on restrictions imposed by specific end equipment, a dedicated ground plane may not be practical. If ground plane separation is necessary, make a direct connection of the planes at the ADC. Do not connect individual ground planes at multiple locations because this configuration creates ground loops.
Route digital traces away from all analog inputs and associated components in order to minimize interference.
Use C0G capacitors on the analog inputs. Use ceramic capacitors (for example, X7R grade) for the power-supply decoupling capacitors. High-K capacitors (Y5V) are not recommended. Place the required capacitors as close as possible to the device pins using short, direct traces. For optimum performance, use low-impedance connections on the ground-side connections of the bypass capacitors.
When applying an external clock, be sure the clock is free of overshoot and glitches. A source-termination resistor placed at the clock buffer often helps reduce overshoot. Glitches present on the clock input can lead to noise within the conversion data.