Abstract: A semiconductor integrated circuit device includes a driving-voltage generating circuit including a diode-connected rectifying element and a resistor element as a voltage generating source, one end of which is connected to one end of the rectifying element and the other end of which is connected to a ground potential, wherein a voltage generated by the resistor element is output to the other end of the rectifying element as a driving voltage.

Abstract: A filter adjustment circuit has a filter capable of adjusting a cut-off frequency that is composed of a plurality of integrators connected to each other, each of which has an amplifier, a resistor connected to an input of the amplifier, a capacitor connected between the input and the output of said amplifier, and a variable resistor connected between the input and the output of said amplifier; a reference frequency generating circuit that outputs a first signal having said cut-off frequency and outputs a second signal that is out of phase with respect to said first signal to said filter; a phase comparator that compares the phase of a third signal, which is said second signal processed by and output from said filter, with the phase of said first signal to determine whether or not the frequencies of the signals are equal to each other; a reference voltage generating circuit that generates a reference voltage having a desired amplitude value for determining a Q factor; an amplitude comparator that compares the

Abstract: A filter adjustment circuit has a filter capable of adjusting a cut-off frequency that is composed of a plurality of integrators connected to each other, each of which has an amplifier, a resistor connected to an input of the amplifier, a capacitor connected between the input and the output of said amplifier, and a variable resistor connected between the input and the output of said amplifier; a reference frequency generating circuit that outputs a first signal having said cut-off frequency and outputs a second signal that is out of phase with respect to said first signal to said filter; a phase comparator that compares the phase of a third signal, which is said second signal processed by and output from said filter, with the phase of said first signal to determine whether or not the frequencies of the signals are equal to each other; a reference voltage generating circuit that generates a reference voltage having a desired amplitude value for determining a Q factor; an amplitude comparator that compares the