yikwon
Newbie level 6
I designed sigma delta ADC using gm-cell integrator.
I've done already loop filter but I couldn't make the summing circuit.
In the first time, I used adder using opamp but it's not suitable because gm-cell has a big in/out impedance, so i have to use more than 3Mohm resistor. it's nonsens in IC design i think.
how to make the summing circuit in sigma delta ADC ??
pls, show me the way.
*I used 5order CIFF type and continuous time filter.
*refer to attached file.
I've done already loop filter but I couldn't make the summing circuit.
In the first time, I used adder using opamp but it's not suitable because gm-cell has a big in/out impedance, so i have to use more than 3Mohm resistor. it's nonsens in IC design i think.
how to make the summing circuit in sigma delta ADC ??
pls, show me the way.
*I used 5order CIFF type and continuous time filter.
*refer to attached file.
