A 150 MHz continuous-time seventh order 0.05/spl deg/ equiripple linear phase filter with automatic tuning system

A full CMOS 150 MHz linear phase low-pass filter is discussed. An Operational Transconductance Amplifier (OTA) based on complementary differential pairs is used to achieve high-frequency operation. A common-mode feedback (CMFB) which ensures stability at high frequencies is introduced. The filter is based on g/sub m/-C biquads, and its inaccuracies are compensated by using a very simple automatic tuning system. Simulation results in a 0.35 /spl mu/m CMOS process have shown group delay ripple of 3% for frequencies up to 180 MHz, while the power consumption is only 37 mW.