Other Parts Discussed in Thread: ADS8684
The ADS8684 we use has a pin, REFIO, which is configured as an external output through the nREFSEL pin. However, in reality, we did not take it as a reference for any other devices; we merely connected a capacitor externally.
This capacitance value can adjust the turn-on time of the internal reference of the chip. It is written in the chip manual that if 22uF is used, it corresponds to 15ms. In our design, the minimum value of 10uF was selected according to the manual, but the corresponding turn-on time could not be read or calculated from the chip manual.
I'd like to ask for your advice
1. How can I calculate the turn-on time for a specific capacitance value? How much turn-on time does 10uF correspond to?
2. How does the turn-on time affect the working mode and performance of the chip?
3. Is there any tendency towards the choice of turn-on time？
4. When is the turn-on action executed? Is it after the POR action only or during the sampling action of ADC?
Bellow are the parameter from datasheet and my schematic, pin REFIO is only connected to C79, whcih is 10uF.
