Patent ID: 8570309

Claim:
A buffer comprising: an input unit between a first power source and a second power source having a voltage lower than the first power source, and for receiving an input signal to output a first signal; a first inverter between the first and second power sources, and for receiving the first signal and the input signal to output a second signal obtained by inverting the first signal; a second inverter between the first and second power sources, and for receiving the second signal and the first signal to output a third signal obtained by inverting the second signal; and an output unit coupled between the first power source and a third power source having a voltage lower than the second power source, and for receiving the third signal and the second signal to output an output signal obtained by inverting the third signal, wherein the input unit comprises first, second and third transistors coupled in series between the first and second power sources, the third transistor comprising a gate directly electrically connected to the second power source.