Semiconductor resistor element

Claim 1

A semiconductor resistor element operatively connected to receive a control voltage, said resistor element comprising: wirings being formed at both ends of a polycrystalline semiconductor film which is formed in a desired topological shape; a control electrode, being provided on said polycrystalline semiconductor film between said two ends via an insulating film, operatively connected to receive said control voltage for controlling the resistance of said polycrystalline semiconductor film; and a circuit for generating said control voltage including MOS transistor Q a through Q j connected between a power supply and ground, the respective drains and gates being short-circuited, and transistors Q m and Q n connected in series between a positive power supply and a gegative power suppy, the transistors Q a through Q i have nearly the same mutual conductance, the transistor Q j has a small mutual conductance, the transistor Q m serves as a resistor with its drain and gate being short-circuited, the transistor Q n receives a voltage from a point at which the transistors Q i and Q j are connected together, and said control voltage is otained from a point at which the transistors Q m and Q n are connected together.