| 摘要 |
PROBLEM TO BE SOLVED: To provide a low-pass filter for removing DC offset without employing a multiplier having a complicated structure by providing a DC offset removing circuit employing an adder having a simple structure in a feedback loop in a CIC(Cascade Integrator-Comb) filter. SOLUTION: The low-pass filter is provided with a first processing means, a down sampler and a second processing means. The first processing means is provided with at least one combination consisting of an adder 10, a one sample delay element 15 and a DC offset removing circuit 20. A 1/R down sampler 12 uses a result of down-sampling of an output from the first processing means as an input into the second processing means. The second processing means is provided with at least one combination consisting of an adder 13 and an M sample delay element 17. |
