Parallel resonant circuit
AssigneeSocionext Inc.
InventorsTakafumi NASU, Shinichiro UEMURA, Atsushi OHARA
Life of this patent
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Abstract
A parallel resonant circuit with excellent distortion and saturation characteristics is provided at low power consumption. A first power-supply voltage is applied to the parallel resonant circuit. In the parallel resonant circuit, a variable resistor includes one or more parallel-connected branches. Each of the branches includes a series circuit of a resistor and a MOS switch. A second power supply supplies power of control signals applied to respective gates of the MOS switches, and supplies back gate voltages to the MOS switches. A power-supply voltage of the second power supply is higher than the first power-supply voltage.
Claims20
A parallel resonant circuit formed by connecting an inductor, a capacitor, and a variable resistor in parallel and connected to a first power supply, wherein
- the variable resistor includes one or more parallel-connected branches,
- each of branches includes a series circuit of a resistor and a MOS switch,
- a second power supply supplies power of control signals applied to respective gates of the MOS switches, and supplies back gate voltages to the MOS switches, and
- a power-supply voltage of the second power supply is higher than a power-supply voltage of the first power supply.
The parallel resonant circuit of claim l, wherein
- a control circuit supplies the control signals to the respective gates of the MOS switches,
- the control circuit includes
- a logic circuit operated by a power-supply voltage of a third power supply, and
- a level shifter operated by a power-supply voltage of the second power supply based on an output of the logic circuit, and outputting the control signals, and
- the power-supply voltage of the third power supply is not higher than the power-supply voltage of the first power supply.
A parallel resonant circuit formed by connecting an inductor and a variable capacitor in parallel and connected to a first power supply, wherein
- the variable capacitor is formed by connecting a plurality of branches in parallel,
- each of the branches includes a series circuit of a capacitor and a MOS switch,
- a second power supply supplies power of control signals applied to respective gates of the MOS switches, and supplies back gate voltages to the MOS switches, and
- a power-supply voltage of the second power supply is higher than a power-supply voltage of the first power supply.
Dependencies are inferred from the claim text.