these are the schematic of my capacitance sensing board and some detals. How can I isolate the influence of ADG734 to the AD7147 sensing. like, when sensing chanel 1, the OUT1 in ADG734(U5) is in High-impedence state. But I think High-impedence state is not enough. Could someone give me some advice? Thanks!
Because I want to measure 7 capacitors, and I want to change the potential of other capacitor plates. For example, there are 7 capacitors, when measuring capacitor 4, I want to set several metal plates HIGH, and set several metal plates connect to GND. I think it will reduce stray capacitance. The problem is that when measuring a capacitance, not only the capacitor I want to meaure, also the capacitance of AD7147(maybe the entire PCB) are measured. I want to achieve that when measuring capacitor x, the OUTx in ADG734 is open, like High-impedence state. Sorry, I don't know I explain clearly or not, maybe not hahaha. 
So, If there ADG734 can have three states or three outputs? Like this photo:
I know ADG733 has an ENABLE state, but I think it's not enough.
And I also know High-impedence state is not completely open, I want to achieve complete open, so the AD7147 only measure the capacitance of the capacitor composed of the metal plates.
soooooooo much thanks!!
Because I want to measure 7 capacitors, and I want to change the potential of other capacitor plates. For example, there are 7 capacitors, when measuring capacitor 4, I want to set several metal plates HIGH, and set several metal plates connect to GND. I think it will reduce stray capacitance. The problem is that when measuring a capacitance, not only the capacitor I want to meaure, also the capacitance of AD7147(maybe the entire PCB) are measured. I want to achieve that when measuring capacitor x, the OUTx in ADG734 is open, like High-impedence state. Sorry, I don't know I explain clearly or not, maybe not hahaha.
So, If there ADG734 can have three states or three outputs? Like this photo:
I know ADG733 has an ENABLE state, but I think it's not enough.
And I also know High-impedence state is not completely open, I want to achieve complete open, so the AD7147 only measure the capacitance of the capacitor composed of the metal plates.
soooooooo much thanks!!
