| 摘要 |
PURPOSE: To provide a PMOS output circuit in which no current flows to a power supply even when a voltage is applied to an output terminal. CONSTITUTION: A back gate 2 of a PMOS transistor(TR) 1 of the output circuit is connected to a power supply 8 via a parasitic PNP TR 24 and NMOS TRs 35, 36 are conductive when an output terminal voltage is higher than the power supply voltage by a threshold voltage of a PMOS TR 81. Thus, the PMOS TR 1 is nonconductive and its drain and gate are short-circuited by the PMOS TR 11, then the reverse flow of a current from the output terminal to the power supply is prevented. |
