| 摘要 |
In a level shift circuit, the threshold voltage of N-type high-voltage transistors, to whose gates the voltage of a low-voltage supply VDD is applied, is set low. An input signal IN powered by the low-voltage supply VDD is input to the gate of an N-type transistor by way of an inverter. Therefore, even if the potentials at nodes W 3 and W 4 exceed the voltage of the low-voltage supply VDD, reverse current flow from the nodes W 3 and W 4 via parasitic diodes within the inverters into the low-voltage supply VDD is prevented. A protection circuit, composed of N-type transistor whose respective gates are fixed to the low-voltage supply VDD, is disposed between the two N-type high-voltage transistors N 5 , N 6 and two N-type low-voltage transistors N 1 , N 2 for receiving the complementary signals IN and XIN, thereby preventing the breakdown of those N-type complementary-signal-receiving transistors.
|
