| 摘要 |
An input decision circuit includes a comparator outputting either one of a high voltage or a low voltage on the basis of the result of a comparison between a reference voltage and an input voltage, a base voltage source acting as a base common to the reference voltage and the input voltage, a constant current source supplying a constant current to a constant current path from a DC power supply to the base voltage source, and a resistor inserted in the constant current path. A constant voltage is produced across the resistor for the reference voltage with the electric potential of the base voltage source acting as a base. This provides an input decision circuit in which a threshold voltage is hard to shift even when the driving voltage of the comparator or the electric potential of the ground acting as the base voltage source is varied. |
