Analog current output circuit

An analog current output circuit in which an output transistor and a load are connected in series between a power supply and a ground and that controls a passing current of the output transistor such that an analog output current to the load coincides with an output command current, wherein

• a voltage of the power supply is a first power supply voltage or a second power supply voltage lower than the first power supply voltage switched by a power supply voltage switching circuit,
• the power supply voltage switching circuit is configured to, according to a comparison result of a comparator that compares an internal control voltage and a load end voltage, select the first power supply voltage when the internal control voltage is smaller than the load end voltage and select the second power supply voltage when the internal control voltage is larger than the load end voltage, and
• the internal control voltage is generated by an internal control voltage generating circuit such that the internal control voltage is 0 volt from an analog output current 0 to a predetermined analog output current value and indicates a rightward-rising voltage track proportional to an electric current from the predetermined analog output current value to a maximum of the analog output current and crosses, at the maximum of the analog output current, a load end current generated when a resistance of the connected load is resistance near the center of a specification range.