I have a project to design a 4th-order source follower lowpass filter for medical applications. Here are the specifications:
1. Supply Voltage: 2.5V
2. Filter order: 4th-Order
3. Cutoff Frequency: 3kHz, 5kHz, 8kHz, 10kHz programmable
4. Power Consumption: <2mW
5. Design Tech: 0.35um CMOS
I am using Cadence Virtuoso to design and simulate the circuit. I am designing the internal circuit of the opamp using NMOS and PMOS transistors. So I use the biquad design and it doesn't seem to be working. I need help in whether the biquad design is suitable or there is other better circuit design. Thanks a lot!