The 73M1903C analog front-end (AFE) IC includes fully differential hybrid driver outputs, which connect to the telephone line interface through a transformer-based DAA. The receive pins are also fully differential for maximum flexibility and performance. This arrangement allows for the design of a high-performance hybrid circuit to improve signal-to-noise performance under low receive level conditions, and compatibility with any standard transformer intended for PSTN communications applications.
The 73M1903C device incorporates a digital host interface that is compatible with the serial ports found on most commercially available DSPs and processors and exchanges both payload and control information with the host. This interface can be configured as a single master/slave mode or as a daisy-chain mode that allows the user to connect up to eight 73M1903C devices to a single host for multiple AFE applications such as central server modems.