| 摘要 |
PURPOSE:To decrease number of components by connecting the 1st input terminal to a control terminal of the 1st and 2nd comparators via a diode and connecting a reference terminal and a control terminal of the 1st comparator with a resistor. CONSTITUTION:The input discriminating circuit of two comparators, its control terminal is connected respectively to the 1st input terminal 100 and the 2nd input terminal 200 via a diode 1 and the 1st resistor 2, the reference terminal is connected respectively to the 1st reference power supply 9 and the 2nd reference power supply 16, and the control terminal and the 1st reference power supply are connected by the 2nd resistor 20. Then the circuit is so designed that the control terminal voltage is decided definitely when the diode is turned on and decided by the 2nd input terminal voltage, the 1st reference power supply voltage, and the 1st and 2nd resistors when turned off, allowing the circuit to act like the input discrimination circuit, even if the 1st input terminal has a ternary level and the 2nd input terminal has binary level. |
