Internal Reference Voltage

Question

Hello,

When AVcc drops when power is removed, ADC measurements become inaccurate. I want to detect AVcc mistake and ignore that measurements. How can i do it?

I thinked that to use internal voltage reference but, i'm not sure how to use it. Because I'm using S12AD2 as continuous scan mode and internal voltage referance can only measurable at Group Scan Mode. I'm using RX66T series uC.

I need your guidance.

Thanks.

ZD · Accepted Answer

Thank you JimB for your comment. 
 Kevin's suggestion solve my problem at the following link. 
 RX65N - Can I use the Internal Reference Voltage to compensate for AVCC0/1 inaccuracy ?

JimB · Answer

I believe the best approach would be include capacitance on the power supplies required for operation, at least enough to be able to detect a power loss and take an necessary shut-down action. The raw (e.g. 12V) supply voltage would need to be monitored with a resistive divider on an ADC pin. Once this raw power signal drops out, do what housekeeping needs to be done before the small reserve supply expires.

Internal Reference Voltage

Top Replies