DESIGN METHOD OF LOW PASS IIR FILTER AND LOW PASS IIR FILTER

摘要

The present invention discloses a design method of a lowpass IIR filter and a lowpass IIR filter suitable for the same. The apparatus of the present invention includes a delayer 21 for receiving an input signal x (n) for a predetermined time delay, a shifter 22 for shifting the output of the delayer 21 by one bit to the MSB side, and a delayer 21. A delayer 23 for delaying the output of the predetermined time, a delayer 24 for receiving the output signal y (n) and a predetermined time delay, and a shifter for shifting the output of the delayer 24 to the MSB side by two bits ( 25, a delay 26 for delaying the output of the delayer 24 by a predetermined time, a subtractor 100 for subtracting the output of the shifter 25 from the output of the delayer 23, and a subtractor 100. A subtractor 200 for subtracting the output of the shifter 22 from the output of the adder, an adder 300 for adding the input signal x (n) and the output of the subtractor 200, and an output of the adder 300 and the coefficient c. A multiplier 350 for multiplying, a subtractor 400 for subtracting the output of the delayer 26 from the output of the delayer 24, a multiplier 450 for multiplying the output of the subtractor 400 and the coefficient 2t, multiplication The adder 500 adds the output of the machine 350 and the output of the multiplier 450, and the adder 600 adds the output of the adder 500 and the output of the delayer 26. here,; Is the critical frequency and Τ is the sampling time. Therefore, the present invention has the advantage that the size of the hardware is reduced due to the reduced number of multipliers.