TP3094 COMBO® Quad PCM Codec/FilterThe TP3094 is a monolithic PCM Codec and Filterdevice implemented using a digital signal processingarchitecture. It provides four voicechannels, combining transmit bandpass and receivelow pass channel filters with companding Alawor m-law PCM encoders and decoders. Thedevice is fabricated using National’s advancedCMOS process.The device includes anti-aliasing filters and sigma-delta converters dedicated to each channel,and by a common signal processing unit whichperforms all the remaining filtering and processingfor the four channels.The TP3094 includes a flexible PCM digital interface,which allows the device to be connected toPCM busses of different formats. It can also beconnected with other TP3094 devices in a cascadefashion, for a system with up to 128 POTSinterfaces (when a 2.048MHz PCM bus is used).