Thank you for your fast, and kind reply.
Our system consumes under 10mA, battery voltage 3.7V, internal digital supply 1.8V, analog voltage 3.3V
I have two followed questions.
1. Where should I insert the isolator? between
1) AFD - ADC
2) ADC - MCU
3) MCU - Charger
4) Charger - Battery (if I use disposable battery, then LDO - Battery)
2. Is there any recommended IC for low power consumption? The ADuM5010 consumes 2~3mA current in steady state, but it is large portion in our system