5th-Order Continuous-Time Low-Pass Filter Achieving 56 MHz Bandwidth 30.5 dBm IIP3 With a Novel Low-Distortion Amplifier

This brief presents a highly linear and high-speed operational amplifier that consists of a double-recycling folded cascode input stage and an adaptive biasing with a flipped voltage follower to boost slew-rate and unity-gain frequency. In addition, frequency compensation is performed by an input cross-coupled phase-lead passive compensation scheme and hybrid Miller-cascode compensation. A 56 MHz -3 dB bandwidth fifth-order programmable gain continuous-time active low pass filter is fabricated in 180 nm CMOS to validate the proposed scheme. The filter achieves 30.5 dBm of third-order interception point at 38 MHz and occupies 0.215 mm
²
. The filter consumes 14.7 mW with 1.8 V supply and has 0.2 dB in-band ripple.