The simple bi-directional serial digital interface controls all on-chip registers, supports the C with clock-reset- and clock-control-signals and handles the highly efficient power up/down management including a clock-free total shut-down of the whole transceiver system. The device has a very low current consumption when operating at a power supply range from 2.3V to 5.25V, in addition it can be powered down when not in use. The device is fabricated in a ustriamicroystems' a dvanced 0.35m CMOS technology and available in QFN40 (6x6) packages.