Amplifier circuit with variable temperature coefficient of gain, and circuit for generating voltage with variable temperature coefficient, which becomes reference potential at reference temperature, direct voltage generating circuit, and circuit for compensating for temperature drift of another amplifier circuit, which use the amplifier circuit

An amplifier circuit with a variable temperature coefficient of a gain, wherein:

• a variable resistor 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 is connected to an input of a buffer amplifier, and
• an output of the buffer amplifier is used as an output, wherein
• the first signal is an output of a first temperature coefficient circuit, and
• the second signal is
• an output of another amplifier circuit,
• an output of a second temperature coefficient circuit,
• an output of a temperature coefficient inverting circuit configured to use the first signal as an input, or
• an input of the amplifier circuit with a variable temperature coefficient of a gain.