| 摘要 |
PURPOSE:To obtain a constant current circuit which is stable enough to the temperature change by combining the circuits having the tendencies adverse to each other against the temperature change. CONSTITUTION:In the 1st closed loop circuit 41 the transistors Tr 1 and 2 are actuated in an intensive reverse area and the Tr 7 and 8 are actuated in a weak reverse area, respectively. Then the current value flowing in the circuit 41 increases by about 10% at 100 deg.C compared with -50 deg.C. While the current flowing in the 2nd closed loop circuit 42 where the Tr 5, 6, 10 and 11 are actuated in an intensive reverse state increases about 10% at -50 deg.C compared with 100 deg.C. The current of a Tr 3 is decided by the ratio of gain coefficients between the Tr 1 and 3; while the current of a Tr 4 is decided by the ratio of gain coefficients between the Tr 5 and 4. Therefore the levels of the current flowing to a Tr 9 are approximately equal to each other between -50 deg.C and 100 deg.C by securing an equal gain coefficient between both Tr 3 and 4.
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