| 摘要 |
PURPOSE:To specify the output current values per integrated circuit by a method wherein a mirror circuit is composed of the first and second constant current circuits while the second detecting element is provided with a reference element and a multitude of controlling elements which are selected by a selecting circuit. CONSTITUTION:A mirror circuit is composed of the first constant current circuit comprising a voltage comparator 6a, a resistor 5a and the second current circuit comprising a MOS transistor 4b, another voltage comparator 6b, another resistor 5c while a detecting element in the second constant circuit is provided with a reference element 5c and a multitude of adjusting elements 5d, 5e which are selected by a selecting circuit 8. Accordingly, even if the values of the reference detecting element 5c are subjected to any dispersion, the current running in the voltage decline element 5b generating the reference voltage in the first constant current is kept at specified value with high precision so that a current controlling element 4a may be controlled by the first constant current circuit while the driving current of a light emitting diode 3 may be kept at the specified value. Through these procedures, the driving current values for integrated circuit can be easily stabilized. |
