| 摘要 |
In a level shifter, first and second PMOS transistors are connected in series between first and second power sources for supplying first high level and low level voltages, respectively, and a capacitor is formed between a contact point of the first and second transistors and the second transistor's gate. A third PMOS transistor is diode-connected and connected between the first and second transistors' gates. When a second low level voltage is input to the first transistor's gate, a second high level voltage is output to the contact point according to an on resistance ratio of the first and second transistors. When a first high level voltage is input to the first transistor's gate, the second transistor is bootstrapped according to the voltage charged to the capacitor so that a first low level voltage is substantially output to the contact point. Since the level shifter outputs voltages substantially corresponding to voltages which the first and second power sources supply respectively, a range of the output voltage may be extended.
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