LNBP21 is a monolithic voltage regulator and interface IC intended for analog and digital satellite STB receivers/SatTV, sets/PC cards. It is assembled in SO-20 and PowerSO-20 and is specifically designed to provide the power and the 13/18V, 22KHz tone signalling to the LNB down converter in the antenna or to the multiswitch box. In this application field, it offers a complete solution with extremely low component count, low power dissipation and simple design together with I2CTM standard interfacing. The IC has a built in DC/DC step-up controller that, from a single 12V supply, provides 2.5V and 13.5V voltages to meet the LNB power requirements. It also features an accurate built-in 22KHz tone oscillator for transmitting 22KHz tone signal to the LNB.