Semiconductor device including resistor having precise resistance value

Abstract

This invention provides a semiconductor device including a circuit having a resistor element whose resistance value can be controlled via application of a control voltage, and permits the circuit to be designed stably without requiring labor and time for adjustment of the control voltage to be applied to the resistor element for precisely controlling resistance of the resistor element, and without increasing chip area. One preferred embodiment includes a reference resistor, such as a carbon film resistor or a chip resistor having a dispersion of approximately .+-.1% and having a very highly stable resistance value, and a diffused layer resistor which is used as the resistor element. The diffused layer resistor has a dispersion of approximately .+-.30% in a LSI circuit. The reference resistor and diffused layer resistor are connected in series between a power source voltage and ground potential, and the potential at the junction between the reference resistor and the resistor element is inputted to the negative input terminal of an inverting amplifier. A potential equal to one half the power source voltage is inputted to the positive input terminal of the inverting amplifier, and the output of the inverting amplifier is fed back as the control voltage for controlling the resistance of the diffused layer resistor, so that the potentials of the positive and negative input terminals of the inverting amplifier become equal.

Dependencies are inferred from the claim text.