The new flagship Si3218x single-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 controller, patented low-power ringing (LPR), and a very low-power on-hook mode. PCM/SPI and our three-wire integrated serial interface (ISI) options are supported.