Lattice Semiconductor iCE40 UltraPlus 8:1 Microphone Aggregator Board

The 8:1 Microphone Aggregator Board is used to develop microphone aggregation applications using the Lattice Semiconductor iCE40 UltraPlus MDP. A downloadable demo allows data transfer from up to eight PDM microphones on a single data wire using an I²S 8-channel aggregation format. The I²S bus is widely used to communicate Pulse Code Modulation (PCM) audio data between integrated circuits in an electronic device. The iCE40 UltraPlus 8:1 Mic Aggregation Board implements a customized I²S bus using the iCE40 UltraPlus FPGA.

Each of the eight microphone’s PDM format data streams are converted to PCM format using an efficient CIC Filter followed by a Compensation Filter. The eight PCM format streams then enter a serializer TDM block that outputs the serialized data in an I²S 8-channel aggregation format to board header J30.