An integrated 120 volt AC mains voltage interface in standard 130 nm CMOS

A circuit technique for directly interfacing with 120 V AC mains in conventional CMOS is presented. An on-chip capacitive divider steps-down the 120 V AC supply, which is then regulated. The approach makes use of the very high breakdown voltage of the dielectric between interconnect layers in conventional CMOS technology. This fully integrated scheme is orders of magnitude smaller than traditional approaches. A prototype circuit is fabricated in 130 nm CMOS and converts 120 V AC to a 3.5 V DC supply.