Level shifting circuit and active matrix driver
AssigneeSharp Kabushiki Kaisha
InventorsGraham Andrew Cairns, Christopher James Brown
Life of this patent
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Abstract
A level shifting circuit comprises a first low power, low speed level shifter 30 and a second high power, high speed level shifter stage 31. Both the stages 30, 31 have signal inputs connected to a common input IN for receiving signals, at least one of whose levels is to be shifted. The output of the first stage 30 is connected to an enable input EN2 of the second stage 31 and switches the operation of the second stage 31 between an enabled state and a disabled state in which the second stage 31 consumes little or no power. The first stage 30 has an enable input EN1 which may be permanently enabled.
Claims28
A level shifting circuit comprising:
- a first level shifting stage having a first enable input, a first signal input for receiving an input signal having a first voltage swing, a first output for providing a first output signal having a second voltage swing greater than the first voltage swing, a first power consumption when enabled, and a first switching speed;
- and a second level switching stage having a second enable input connected to the first output, a second signal input for receiving the input signal, a second output for providing a second output signal having a third voltage swing greater than the first voltage swing, a second power consumption when enabled and a third power consumption when disabled with the second power consumption being greater than each of the first and third power consumptions, and a second switching speed which is faster than the first switching speed.
Dependencies are inferred from the claim text.