Performance comparison of high-order IFLF and LF linear phase lowpass OTA-C filters with and without gain boost
Design and performance comparison of highorder operational transconductance amplifier and capacitor (OTA-C) filters using leapfrog (LF) and inverse-followthe- leader-feedback (IFLF) structures are investigated. The filters are designed for a 125 MHz seventh-order equiripple group delay lowpass characteristic with and without gain boost and simulated in 0.25 mu m 2-V CMOS. A fully differential highly linear OTA with cross-coupled input pairs and regulated cascode output is used for the simulation. Simulated results show that while the IFLF OTA-C filter can achieve a higher gain boost, the LF OTA-C filter has better other performances.
ota-c filters active filters continuous-time filters multiple loop feedback filters linear phase filters