AC meter clamp in sleep mode

[perv]

Hello,

I am using a PIC18LF26K40 to read the output voltage of the AC meter clamp.
One of the AC meter clamp output pin is connected to an analog pin of the PIC
The other AC meter clamp output pin is connected to Vcc using a 470 Kohm resistor and to nd using a 470 Kohm resistor and a capacitor in parallel.

What is the configuration of the analog pin of the PIC that I need to have during the sleep mode in order to reduce energy consumption : output or input ? value = low or high ? WPU active ?

Does I need to add a resistor before the analog input pin of the PIC ?

Thanks

 

[KlausST]

Hi,

With this setup the whole current clamp is almost floating, thus picking up any noise around.
Better do it the other way round:
GND - [clamp_minus - clamp_plus] - capacitor - voltage divider (470k to GND, 470k to VCC) and ADC.

For low power you usually an the voltage at the pins either close to GND or close to VCC.
So if you switch the pin to OUT, LOW then it should be fine. But it draws 470k @5V in the voltage divider.

Mind that it needs some time to settle to VCC/2 after power down.

Klaus