| 摘要 |
PURPOSE:To avoid the destruction of the output circuit, by holding the output terminal of the logic circuit at high impedance with the output signal of the voltage detection circuit outputting signal when the power supply voltage reaches a given value, in tristate output type semiconductor integrated circuit. CONSTITUTION:The tristate control circuit 1 is connected to the tristate output type semiconductor integrated circuits 31,32...3n, and the integrated circuits 31,31...3n are connected to the bus line 2. Further, every integrated circuit is provided with the power supply detection circuit 6 outputting singal when the power supply voltage Vcc reaches a given value, and the output of the detection circuit 6 is fed to another input of the NOT sum circuit feeding the output of the control circuit 1 to one input, the inverter 4 is controlled with the output signal of the circuit 5, holding the output of the integrated circuits 31,32...3n to a high impedance until the power supply voltage Vcc reaches a given value. |
