| 摘要 |
PURPOSE:To compensate a leakage of a lateral PNP to a substrate caused by the structure of a monolithic IC and not to be compensated in any way at a glance by arranging skillfully the current mirror and utilizing it. CONSTITUTION:A current source I3 enters a lateral PNP current mirror input terminal 36, flows out of an output terminal 35 and when a current I11 entering a power supply V4 is desired to be matched as well as possible with the current I3, since a potential difference between the terminals 35 and 36 is large, a current flowing out of the terminal 35 is larger than the I3 by the decrement of the current leaked to the substrate. Further, voltages at terminals 22, 23 are almost equal by decreasing the voltage V3 applied to the current mirror 26 less than the V4 by nearly 0.7V. Thus, the current I8 flowing out of the 2nd output terminal 34 of the current mirror 25 is equal to the I7. Then, the relation of I7=I3+epsilon and I8=I3+epsilon is obtained, where epsilon is input/output terminal current difference of the current mirror caused by a voltage difference of the collector-emitter voltage difference of the lateral PNP. In flowing the current I4 having the identical value to the I3 from an NPN current mirror 26, the relation of I5=I8-I4=epsilon is obtained and the I11 becomes an equal value to the I3.
|
