Oscillator circuit and L load differential circuit achieving a wide oscillation frequency range and low phase noise characteristics

An L load differential circuit, comprising an inductor pair including first and second inductance-variable portions having second input/output terminals commonly connected to a fixed node and being capable of varying inductances, and a first switch circuit coupled between first input/output terminals of said first and second inductance-variable portions, wherein

• each of said first and second inductance-variable portions has
• a spiral interconnection layer starting from said first input/output terminal, and
• a plurality of second switch circuits having first terminals connected to arbitrary positions on said interconnection layer, respectively, and having second terminals commonly connected to said second input/output terminal,
• when one of said plurality of second switch circuits is turned on, the position on said interconnection layer connected to said turned-on second switch circuit is electrically coupled to said second input/output terminal, and
• when said first switch circuit is turned on in response to the turn-on of said second switch circuit, said first switch circuit electrically couples said first and second inductance-variable portions.

An L load differential circuit, comprising an inductor pair including first and second inductance-variable portions having second input/output terminals commonly connected to a fixed node and being capable of varying inductances, and a first switch circuit coupled between first input/output terminals of said first and second inductance-variable portions, wherein

• each of said first and second inductance-variable portions has
• a plurality of spiral interconnection layers starting from said first input/output terminal, and
• a plurality of second switch circuits coupled between trailing ends of said plurality of interconnection layers and said second input/output terminal, respectively,
• when one of said plurality of second switch circuits is turned on, the trailing end of said interconnection layer included in said plurality of interconnection layers and connected to said turned-on second switch circuit is electrically coupled to said second input/output terminal, and
• when said first switch circuit is turned on in response to the turn-on of said second switch circuit, said first switch circuit electrically couples said first and second inductance-variable portions.