High-Precision 24-bit FIR Decimation filter optimum design for MEMS geophone
Xin We · Progress in geophysics · 2015
High precision decimation filter is widely used in the DSP chip of MEMS digital detector,which enables detector output low-speed high-precision data for subsequent processing.FIR filter is generally aequl-ripple filter,and the hardware implementation requires a coefficient of 24 truncated length,but rounding the coefficients obtained by remez algorithm will seriously affect the stop-band attenuation,whichcan not meet international standardof 130 dB.In this paper,for our self-developed MEMS digital geophone,we use simulated annealing algorithm that based on the max-min criteria to optimize the design of the compensation decimation filter so as to reach a flat passband response,and further reduction of data rate.Simulation results show that the passband ripple is in the range of ±0.003 dB,stop-band attenuation reaches 132 dB,which fully meet the performance indicators of MEMS digital geophone.The proposed design approach is common to design high precision decimation filter.