| 摘要 |
PROBLEM TO BE SOLVED: To provide an input determination circuit that impedes a threshold shift in a predetermined range on both on and off sides even if a driving voltage of a comparator or a ground potential fluctuates.SOLUTION: The input determination circuit (20) having the comparator (4) for outputting either a high voltage (Hi) or a low voltage (Low) on the basis of a result of comparison of an input voltage (VIN) with a reference voltage (Ref) comprises: a reference voltage source (21) for providing a common reference for the reference voltage (Ref) and the input voltage (VIN); a constant current source (5) for supplying a constant current to a constant current path leading to the reference voltage source (21); and a resistance (R) inserted in the constant current path. A constant voltage generated across the resistance (R) with reference to the reference voltage source (21) is used as the reference voltage. |
