The L7585G Full-Feature, Low-Power Subscriber Loop Interface Circuit (SLIC) and Switch integrates the battery feed, test access relay, and ringing relay that are necessary to interface a codec to the tip and ring of a subscriber loop into one low-power, low-cost package. It is built using a 90 V complementary bipolar (CBIC) process and a 320 V Bipolar-CMOSDMOS (BCDMOS) process. The device is available in a 44-pin MQFP package.