A full custom half-band filter used for sigma-delta ADC

Abstract

A low power full custom Half-Band FIR digtal Alter with fixed coefficients used for sigma-delta ADC is presented. The Half-Band FIR digtal filter uses three- stage cascaded strcture and has linear phase and lowpass characteristics. It achieves passband ripple of 0.003dB and stopband attenuation of 82dB, and dissipates only 15mW with a 3V supply based on a 0.35um CMOS process.