NEW LOW ROUNDOFF NOISE REALIZATIONS OF 2ND-ORDER DIGITAL-FILTER SECTIONS

New structures for second-order filter sections are proposed that yiel d lower output roundoff noise than many well known structures and are free of zero-input limit cycle oscillations, These new low-roundoff st ructures are based on these suggested by Bomar in [9] and [10] and are obtained by putting the constraint that some of the state-space coeff icients be sum-of-two power-of-two terms. Numerical results are includ ed to illustrate the performance of the proposed structures for narrow -band filters and to compare them with other structures.