COMMON LEVEL SHIFTER, PRECHARGE CIRCUIT, SCAN LINE DRIVER HAVING THE SAME, LEVEL SHIFTING METHOD AND SCAN LINE DRIVING METHOD

摘要

A common level shifter, a precharge circuit, a scan line driver having the same, a level shifting method and a scan line driving method are provided to reduce the number of level shifters designed in a high voltage region. The precharge circuit outputs a voltage of a selection signal of a first voltage level through an output port by being synchronized to a first clock having the first voltage level. A pull-down part(416) is turned on when the selection signal is inactive, and provides a first power supply voltage having a base voltage level lower than the first voltage level to the output port. A pull-down driving part(418) turns on the pull-down part by being turned on when the selection signal is inactive, and is turned off when the selection signal is active. A first charging part(411a) charges the output port with a second power supply voltage having a second voltage level higher than the first voltage level, when the selection signal is active. A first discharging part(412) provides a third power supply voltage to the output port and discharges the first discharging part by being turned on in response to the inactive state of a fourth clock of the second voltage level synchronized to the second clock having an inverted phase of the first clock. A second charging part(419a) is charged with the third power supply voltage having the first voltage level in response to the inactive state of the selection signal. And a second discharging part(414) turns off the pull-down part by being turned on in response to the inactive state of a third clock having the second voltage level synchronized to the first clock, and discharges the second charging part.