| 摘要 |
PURPOSE:To obtain a desired current limiting resistance value simply by the small quantity of trimming, and to reduce the change of the resistance value of a current limiting resistor resulting from a secular change by constituting the current limiting resistor by a trimming resistor capable of trimming and a reference resistor connected in series with the trimming resistor. CONSTITUTION:The resistance values of trimming resistors Rx1-Rxn are changed through a trimming by using a laser. One ends of reference resistors R1-Rn are each connected at the other ends of the trimming resistors Rx1-Rxn, and the other ends of the reference resistors are connected severally to emitters in transistors TR1-TRn. Respective resistance value of the reference resistors R1-Rn is set so as to be approximately equalized. The resistance values of the reference resistors are set so as to occupy the greater parts of current limiting resistance values. |
