Junus2012
Advanced Member level 5
Dear friends,
I am trying to design programmable or tunable fc for my LPF. For this puspose I need to have tunable resistor and I will leave the capacitors constans.
Toward this, a MOS transistor is an option, but I believe it will kill the concept of using Active RC filter rather than the gm-c filter because it will result in a comparable non-linearity, especially talking about large signals. While I have seen plenty of papers by using the MOS as a variable resistor but most of those people are processing week bio-signals.
I have in the used technology a very high sheet resistance (HRIS) with size even can be made smaller than equivalent MOS resistor. Here is my question, if such resistor is available why people not using it frequently? most of them they use poly2 resistor which occupy large die area.
would it be better to have tunable HRES bank than using MOS resistor?
Thank you very much
I am trying to design programmable or tunable fc for my LPF. For this puspose I need to have tunable resistor and I will leave the capacitors constans.
Toward this, a MOS transistor is an option, but I believe it will kill the concept of using Active RC filter rather than the gm-c filter because it will result in a comparable non-linearity, especially talking about large signals. While I have seen plenty of papers by using the MOS as a variable resistor but most of those people are processing week bio-signals.
I have in the used technology a very high sheet resistance (HRIS) with size even can be made smaller than equivalent MOS resistor. Here is my question, if such resistor is available why people not using it frequently? most of them they use poly2 resistor which occupy large die area.
would it be better to have tunable HRES bank than using MOS resistor?
Thank you very much