The ADC32RF52 provides up to four internal ADCs per channel for purpose of averaging to improve the noise performance. Two ADCs internally are connected to the same differential input pins as shown in the equivalent input schematic (see Figure 7-1). The analog inputs have a differential 100 Ω split termination with internal biasing. This can be changed to differential 50 Ω termination via SPI register write. When only a single ADC is used, there is a minor parasitic capacitance remaining from the unused ADC.

Figure 7-1 Equivalent Input Schematic