| 摘要 |
PURPOSE:To prevent a harmful current from flowing into an integrated circuit from a common bus connected with an output terminal by interposing a switching circuit turned on/off in interlocking with the on/off of a 1st power supply between the 1st power supply and a 1st MOS transistor (TR). CONSTITUTION:An npn TR 7 as a switching element is interposed between the power terminal 3 and a p-MOST1. The emitter of the npn TR 7 is connected between the source of the p-MOST1 and the bulk and the collector is connected to the power terminal 3 together with the base. With a power supply applying a voltage Vcc is turned off, since the npn TR 7 is turned off in interlocking therewith, the current path between an output terminal X and the power terminal 3 is disconnected. Thus, even when an H signal is supplied to the common bus connecting to the output terminal X from other integrated circuit, no harmful current flows the output terminal X to the power terminal 3. |
