11.1.1.2 Shielding Analog Signal Paths

As with any precision circuit, careful PCB layout ensures the best performance. It is essential to make short, direct interconnections and avoid stray wiring capacitance—particularly at the analog input pins and AVSS. These analog input pins are high-impedance and extremely sensitive to extraneous noise. The AVSS pin should be treated as a sensitive analog signal and connected directly to the supply ground with proper shielding. Leakage currents between the PCB traces can exceed the ADS1291, ADS1292, and ADS1292R input bias current if shielding is not implemented. Digital signals should be kept as far as possible from the analog input signals on the PCB.