The Si3228x dual-channel ProSLIC subscriber line interface circuit (SLIC) devices deliver the lowest power consumption, highest level of programmability, and lowest cost bill of materials in the industry. Unmatched power efficiency is achieved using patented on-chip intelligent dc-dc controllers, patented low-power ringing (LPR), a very low-power on-hook mode, and energy-friendly smart ringing that can save power adapter cost in two channel applications. A selectable digital interface enables the system architect to interface with the SoC via a standard PCM/SPI digital interface or our three-wire integrated serial interface (ISI).