Fast differential level shifter and boot strap driver including the same

An apparatus comprising:

• a pulse width modulation signal generator generating a pulse width modulation signal;
• a level shifter shifting the pulse width modulation signal to a boot strap output voltage having a voltage range from a first boot strap voltage to a second boot strap voltage by differentially amplifying the pulse width modulation signal in two stages;
• and
• an upper driver biased by the first and second boot strap voltages, driving the output of the level shifter and outputting a first driven signal,
• wherein the level shifter differentially amplifies the pulse width modulation signal and an inverted pulse width modulation signal, outputs a first differential amplification voltage and a second differential amplification voltage based on the amplified result, differentially amplifies the first differential amplification voltage and the second differential amplification voltage, and outputs the boot strap output voltage based on the amplified result.