PURPOSE: To keep a voltage at an output terminal to be BE or below and to set an output current at the voltage of BE or below using a stepped-down section so as to step down an output voltage of a logic circuit section to a desired voltage and selecting a VBE of a bipolar transistor(TR) independently of the voltage at the output terminal.
CONSTITUTION: First or second potential is selectively outputted from a logic circuit section 10. When the 2nd potential is outputted selectively from the logic circuit section 10, the level is stepped down into a level being the 1st level or over and the 2nd level or below with a level step down section 11. Succeedingly the step down level is fed to a base of a bipolar TR 12, and when a collector current starts flowing, the level at an output terminal is decreased, and in this case, a breakdown voltage being a base-emitter voltage (VBE) is an output of the level step down section 11 and the output terminal and the base are not short-circuited. That is, the level at the output terminal is decreased without giving any effect onto the voltage VBE. Thus, the level at the output terminal is brought into a Built in Potential (BE) or below and the output current is set with the level of the output terminal to be BE or below.
OKAWACHI TADAHISA
TSUCHIYA IKUO
KIMURA MASAHIRO
TOSHIBA MICRO ELECTRONICS
| JPS619015A | 1986-01-16 | |||
| JPS5919435A | 1984-01-31 | |||
| JPS59117330A | 1984-07-06 |
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