| 摘要 |
A CMOS integrated circuit output terminal driver subcircuit (60) provides quick response at an output terminal (56) of an integrated circuit (50) while preventing reverse current leakage when an external high voltage, which exceeds the positive internal circuit source voltage of the integrated circuit, is imposed on the output terminal (56). The output driver subcircuit (60) additionally provides an output voltage at the output terminal that is only nominally below the internal circuit source voltage. A p-channel MOS pull-up transistor (62) is operably connected to the output terminal (56) to selectively drive it substantially to the internal circuit source voltage. A leakage prevention device (66), comprising a native n-channel transistor (68) with a low turn-on threshold voltage, is connected in series with the pull-up transistor (62) to prevent output terminal reverse current leakage back through the pull-up transistor (62) when the external high voltage is imposed upon the output terminal (56).
|
