US Patent 7536166 Monolithically integrated circuit

A monolithically integrated circuit, particularly an integrated circuit for radio frequency power applications, has a transistor (11; 51), preferably a power LDMOS transistor, and a spiral inductor (12; 26; 41; 52, 53), preferably an RF blocking inductor. The spiral inductor is arranged on top of the transistor, whereby an electromagnetic coupling between the spiral inductor and the transistor is not typically possible to avoid. However, the transistor has a finger type layout (13a-k, 14a-f) to prevent any significant eddy currents caused by the electromagnetic coupling from occurring. The chip area needed for the circuit is strongly reduced by such an arrangement.