Abstract: A supply independent bias start-up circuit which is capable of preventing an additional current consumption which may occur therein after the start-up of a supply independent bias circuit thereof, stabilizing a bias voltage even if an input voltage from a power source is varied, and reducing a layout area thereof. The supply independent bias start-up circuit includes a supply independent bias circuit for inputting a voltage from a power source and generating a constant bias voltage, and a start-up circuit for inputting the source voltage, starting up the supply independent bias circuit at the beginning of apply of the source voltage thereto and blocking its own current loop after the source voltage enters a stabilized state.

Abstract: A current-voltage converting circuit applicable to a linear integrated circuit of CMOS-type having a wide-ranged operational voltage, comprising a buffer circuit for buffering and amplifying a current being input to an input terminal; a gain circuit for outputting a voltage in proportion to the output voltage of the buffer circuit; and a current reference circuit constituted in a current mirror by P-channel transistors; N-channel transistors and a reference voltage and is adapted to supply a constant voltage to gates of P-channel transistors provided in the gain circuit.