Compare active filter topologies and their design considerations.

Common active filter topologies include: Sallen-Key (simple, moderate Q, sensitivity to component variation), Multiple Feedback (inverts signal, better high-frequency response), State-Variable (provides LP, HP, BP simultaneously, easy tuning), Biquad (lowest sensitivity, most components), and Switched-Capacitor (integrates on IC, clock-controlled cutoff). Design considers: filter order and type (Butterworth, Chebyshev, Bessel), component sensitivity, noise, dynamic range, and op-amp GBW requirements. Higher-order filters cascade second-order sections.