A data converter includes multiple analog to digital converters (ADCs) and uses a reduced number of data ports at the digital interface for transferring signal samples. The bits of the signal samples generated in parallel by the ADCs are multiplexed into fewer data streams than the number of ADCs. The data ports transfer the data streams at a higher data transfer rate than the bit rate of the samples output from the ADCs. Unused data ports are powered down, decreasing power consumption and system complexity. A host device receives the data streams using fewer input data ports and demultiplexes the received data streams to reproduce the signal samples. Efficient data transfer to a data converter including multiple digital to analog converters (DACs), from a source device generating multiple digital signals can also use fewer data ports having higher data transfer rates.