| 摘要 |
PURPOSE:To keep normal operation even a power supply voltage is rised by using a voltage suitable for a power supply to an output circuit in an IC having a logical circuit of I<2>L structure. CONSTITUTION:A constant voltage circuit comprising a resistor RA and diodes D1-Dk is provided between a power supply terminal Vcc and ground and a voltage obtained from its output through an NPN transistor (TR)QA of emitter follower connection is used as a power supply voltage to an output circuit of an I<2>L section. A voltage from the terminal Vcc is applied to a linear circuit part. The TRQA is provided to supply the emitter current of TRs turned on among output TRs Q3-1-Q3-n, then a current being only 1/hFE (where; hFE is a current amplification factor of the TRQA) of the emitter current of TRs turned on among the TRQ3-1-Q3-n has only to be supplied to the diodes D1-Dk by the provision of the TRQA. Thus, since the emitter voltage of the output TR is kept to a suitable voltage even the power supply voltage is rised the circuit maintains normal operation. |
