公开(公告)号：US11415666B2

公开(公告)日：2022-08-16

申请号：US16585924

申请日：2019-09-27

Applicant: RENESAS ELECTRONICS CORPORATION

Inventor： Takashi Oshima ,  Tetsuo Matsui ,  Mitsuya Fukazawa ,  Katsuki Tateyama ,  Masaki Fujiwara

IPC: G01S7/35 ,  H03M3/00 ,  G01S13/34

Abstract: A MASH type sigma delta AD converter includes a modulator, an analog filter filtering an extraction signal obtained by extracting a probe signal and an quantization error generated in a quantizer within a sigma delta modulator, a low speed AD converter performing an AD conversion of an output signal of the analog filter, a first adaptive filter searching for a transfer function of the sigma delta modulator, a second adaptive filter searching for a transfer function from an output of the modulator to the low speed AD converter via the analog filter, and a noise cancellation circuit cancelling the probe signal and the quantization error included in an output signal of the quantizer using the search results by the first and second adaptive filters.