| 摘要 |
A hybrid FIR (finite impulse response) filter 60A comprises parallel analogue and digital filter portions 64A and 66A. The filter consumes less power and has lower latency than a conventional FIR filter, and may be used as one or more of the filters (32, 34A, 34B, 44, figure 3) in an ambient noise cancellation system. The filter may be adaptive. To perform latency matching between the filter portions, a delay element 74 may be inserted such that the total delay through the ADC 80, the delay element 74, and the DAC 82 matches the total delay of all of the delay stages 62C in the first filter portion. |
