Abstract
This paper introduces a method named Chopping-Out-Of-band (COOB), which can suppress ripple in chopper amplifiers. By choosing a suitable chopping frequency (fchop) located in GBW < fchop < NLBW (No-Load Bandwidth), the ripple will be suppressed rather than amplified and the effect can be improve further by an extra filter. The COOB technique was employed in instrumentation amplifiers as examples and the extra filter was designed to passive filter. These chopper amplifiers were simulated on UMC 0.18 um technology with the help of Cadence SpectreRF. Simulation results showed that the ripple was suppressed by −93.4 dB in Power Spectral Density (PSD) analysis without additional power consumption.
