公开(公告)号：EP0764368A1

公开(公告)日：1997-03-26

申请号：EP95920120.0

申请日：1995-06-01

申请人： Fincitec Components Oy

发明人： HEIKKILÄ, Juha ,  LIPASTI, Lauri

IPC分类号： H03M3

CPC分类号： H03M3/362 ,  H03M3/43 ,  H03M3/454

摘要： The invention relates to an oversampled high-order modulator, especially a sigma-delta modulator, comprising cascaded integrators (H1, H2, ...HN) in a number corresponding to the order of the modulator, a quantizer (15), and a negative feedback (21, 22, 23, 24). The problem with the high-order modulators is that the modulator is locked in an unstable mode from which it should be restored without considerably interfering with the operation of the modulator. The invention achieves this by temporarily changing the value of the negative feedback to a direction which whill restore the stable operation.