Abstract: A circuit includes a first transistor, a second type-one transistor, a first type-two transistor, a third type-one transistor, a fourth type-one transistor, and a fifth type-one transistor. The first type-one transistor has a gate configured to have a first supply voltage of a first power supply. The first type-two transistor has a gate configured to have a second supply voltage of the first power supply. The third type-one transistor has a first active-region conductively connected with an active-region of the first type-one transistor. Third type-one transistor has a second active-region and a gate conductively connected to each other. The fifth type-one transistor has a first active-region conductively connected with the gate of the third type-one transistor and has a second active-region configured to have a first supply voltage of a second power supply. The fifth type-one transistor is configured to be at a conducting state.

Abstract: A presenter model includes a presenter having a wireless signal transmitting unit and an accommodating box having a wireless signal receiving unit. The accommodating box having the wireless signal receiving unit receives the wireless signals transmitted by the wireless signal transmitting unit of the presenter. Via a USB port connected with an electronic apparatus, the command received is transmitted to the electronic apparatus, thereby achieving the function of transmitting the signals of the presenter. The accommodating box can be provided thereon with at least one insertion slot for a USB interface and at least one insertion slot for an IEEE1394 interface, thereby serving as digital expansion slots. The accommodating box allows the presenter to be disposed therein and combined therewith, thereby increasing the convenience in carrying and storing the presenter.