| 摘要 |
PURPOSE:To accurately obtain a desired electric current value, by connecting the back gate of an MOS type field effect transistor to the 2nd resistance which is connected with a reference electric potential. CONSTITUTION:Emitters of bipolar transistors (Tr) 23 and 22, whose bases are commonly connected, are connected with a power-supply voltage Vss through resistances 24 and 25, respectively. A constant-current output is taken out by connecting an MOS type field effect Tr21 between collectors of the Trs 23 and 22 and supplying the back gate 27 of the Tr21 from the high potential side A of the resistance 24. Therefore, since the voltage of the back gate electrode 27 of the MOS type field effect Tr21 becomes larger when a collector current Ic22 is large and the difference between the collector current Ic22 and another collector current Ic23 is small, the ON-resistance also becomes larger and even a weak error current can be corrected. |
