Using FPGA to achieve fourth-order IIR digital filter section cascaded through two second-order elliptic low-pass digital filter. Less than 0.1dB passband ripple filter inductor Nanjing, stop-band attenuation greater than 32dB. Commonly used digital filters have FIR digital filter and IIR digital filter. FIR digital filter with a precise linear phase characteristics, in signal processing is extensively used, and can be debugged using pre-designed digital FIR filter IP Core to complete the design. Further, for the same design specifications, the order of the FIR filter required than an IIR filter 5 to 10 times higher, the higher production cost filter inductor, and the delayed signal is also large. The order IIR filter required not only lower than the FIR filter, and can use the results of the analog filter design, design work is relatively small, the use of FPGA implementation of IIR filter also has a variety of advantages. TI high-precision analog design solutions from TI analog product experts created. Proven design provides a theoretical analysis, device selection, complete printed circuit board (PCB), you can use the circuit has been tested over the performance. This circuit is designed to be low-frequency noise (0.1Hz to 10Hz) can be enlarged to the level of the magnitude of the oscilloscope easy measurement. It uses a 0.1Hz second order 10Hz high-pass filter and a fourth-order low-pass filter to achieve this functionality. 0.1Hz to 10Hz noise measurement is a critical parameter in common amplifier data sheet. This is designed to simplify the 0.1Hz to 10Hz noise measurement, commonly used in different types of operational amplifier package. Jiangsu filter inductors, filter inductor Nanjing, Wal Teng Technology (certified merchants) provided by Nanjing Wolfowitz Proton Electronic Technology Co., Ltd .. Nanjing Wolfowitz Proton Electronic Technology Co., Ltd. (www.njwtt.com) is specialized in the "electronic components, transformers, filters, inductors, chokes, electronic coils, transformers," the enterprise, the company of "honesty, hard service" concept, to provide you with the highest quality products and services. Welcome to inquire! Contact: Hudong Yu.