ADC bit sampling rate and reference voltage in nRF5340

[shahid Sultan]

I have been reviewing the datasheet of the BLE audio SoC nRF5340. The ADC sampling frequency is mentioned, but the rate is not specified.

he references voltage is specified as 0 to VDD. Can we use 3 V or 3.3 V for Vref?  Also, the term VDDHDIV5 is mentioned—what does it mean and what is its significance?

[Håkon Alseth]

Hi,

 

The ADC sampling frequency is mentioned, but the rate is not specified.

Please see the electrical specification for this:

https://docs.nordicsemi.com/bundle/ps_nrf5340/page/saadc.html#ariaid-title59

he references voltage is specified as 0 to VDD. Can we use 3 V or 3.3 V for Vref?  Also, the term VDDHDIV5 is mentioned—what does it mean and what is its significance?

You have two references to choose from:

https://docs.nordicsemi.com/bundle/ps_nrf5340/page/saadc.html#ariaid-title13

 

VDDHDIV5 is an input, ie. VDDH voltage divided by 5, but please note that the acq time must be >= 10 us if you use that:

https://docs.nordicsemi.com/bundle/ps_nrf5340/page/saadc.html#ariaid-title14

 

Kind regards,

Håkon