Abstract: An amplifier circuit 1001 with a variable temperature coefficient of a gain is an amplifier circuit with a variable temperature coefficient of a gain in which a variable resistor VR is connected between a first signal and a second signal having temperature coefficients of an amplification factor different from each other, a variable output of the variable resistor VR is connected to an input of a buffer amplifier Ub, and an output of the buffer amplifier Ub is used as an output Vo, wherein the first signal is an output of a first temperature coefficient circuit 100, and the second signal is an output of another amplifier circuit 501.

Abstract: A capacitance measuring circuit measures an electrostatic capacitance formed between a first conductor that receive an AC signal and a second conductor. The capacitance measuring circuit includes an amplifier including an input and an output; signal detection means including a negative feedback unit that has a feedback capacitance and applies a negative feedback from an output of the amplifier to an input of the amplifier, wherein an input of the amplifier is connected to the second conductor and is virtually grounded by the negative feedback unit and an AC signal of an amplitude in a functional relation with the electrostatic capacitance is output; and measuring means that is connected to an output of the signal detection means and has a function of measuring at least an amplitude of an AC signal output of the signal detection means.

Abstract: A capacitance measuring circuit measures an electrostatic capacitance formed between a first conductor that receive an AC signal and a second conductor. The capacitance measuring circuit includes an amplifier including an input and an output; signal detection means including a negative feedback unit that has a feedback capacitance and applies a negative feedback from an output of the amplifier to an input of the amplifier, wherein an input of the amplifier is connected to the second conductor and is virtually grounded by the negative feedback unit and an AC signal of an amplitude in a functional relation with the electrostatic capacitance is output; and measuring means that is connected to an output of the signal detection means and has a function of measuring at least an amplitude of an AC signal output of the signal detection means.

Abstract: Provided is a configuration of a driver integrated circuit that can output a voltage exceeding the withstand voltage of a process, and that satisfies required apparatus performance (high speed and high voltage). A differential input circuit, a level shift circuit, and an output circuit are manufactured by the same process and divided and disposed on three or more chips with different substrate potentials (sub-potentials). By setting different applied voltages to the substrates of the chips, an output voltage greater than the process withstand voltage can be provided (see FIG. 2).

Abstract: Provided is a configuration of a driver integrated circuit that can output a voltage exceeding the withstand voltage of a process, and that satisfies required apparatus performance (high speed and high voltage). A differential input circuit, a level shift circuit, and an output circuit are manufactured by the same process and divided and disposed on three or more chips with different substrate potentials (sub-potentials). By setting different applied voltages to the substrates of the chips, an output voltage greater than the process withstand voltage can be provided (see FIG. 2).

Abstract: There is provided a variable gain circuit system which is inductorless and capable of achieving a high gain and a wide band by elements for achieving variable gain to prevent decreasing a gain or deteriorating the band. The variable gain circuit includes: transistors; a resistor connected as a load of each transistor; a voltage source applying a bias voltage to each gate of the transistors; a switch selectively connecting the voltage source or a ground potential to each gate of the transistors in accordance with gain setting; and a current source connected to a common input. A drain of each transistor is connected to an input of a circuit in a subsequent stage.

Abstract: A peaking circuit according to the present invention includes amplifiers connected in multiple stages and feedback circuits for feedback to an input from two or more output points with different gains as seen from the input. The peaking circuit is configured to be able to change an amount of feedback of the feedback circuits.

Abstract: There is provided a variable gain circuit system which is inductorless and capable of achieving a high gain and a wide band by elements for achieving variable gain to prevent decreasing a gain or deteriorating the band. The variable gain circuit includes: transistors; a resistor connected as a load of each transistor; a voltage source applying a bias voltage to each gate of the transistors; a switch selectively connecting the voltage source or a ground potential to each gate of the transistors in accordance with gain setting; and a current source connected to a common input. A drain of each transistor is connected to an input of a circuit in a subsequent stage.