Same ground pin on different ADC Differnetial Channels

[Salman Azmat]

Hi,

I'm designing a pcb for nrf52832, and acc. to specification sheet (2nd para under fig. 98) i need to use differential mode to avoid ground bouncing. Can I share a pin as the negative side in two differential channels ? For example, let's say we are using pins no 4,5,6 (AI0,AI1,AI2), and my first differential channel is configured to use pins 4(+ve) and 5(-ve), and my second differential channel is configured to use pins 6(+ve) and 5(-ve), thus sharing pin 5 as the -ve input.

1. Is such a scenario possible ?

2. Is it possible to create 7 differential channels by having one pin as common -ve input to all 7 channels ?

I cannot experiment myself as I'm still waiting for the dev kit to arrive and I'm really short on time.

Regards,

Salman Azmat

[ketiljo]

Hi

Sure, this is can be done. Remember that there is only one ADC and the input MUX is set before each acquisition. Hence, you can select any combination of pins.