Currently I want to use TLV2771 circuit to connect to our piezoelectric material. I am not sure if it fit our demand.
Actually my major is not in this field. This is all new to me. And I saw a lot of chips in the TLV2771 category, does anybody can explain the difference between each other?
And I go over the reference circuit provided on the website (www.ti.com/.../sloa033a.pdf). I want to make it working in charge mode. The attachment is the circuit we want to use. 
I wanted to double-check that I'm understanding the circuit.
My material parameter is:
Qmax=15nC
Vmax=20V
Cp=0.75nF
Desired to work in low frequency region: 0.01Hz~10Hz
And fL = 1/(2pi*Ri*Cf)
fH = 1/(2pi*Ri(Cp+Cc))
gain = 1/Cf
My calculated values are:
Rf = 500MOhm
Cf = 15nC/5V=3nF
Ri = 20Mohm
I'm not sure if my calculation is correct. And I don't know how to add the Vcc in the graph.
And i don't know how could i started to build the circuit. Is evaluation board needed besides the chips? I appreciate your help very much.