Voltage amplifier and driving device of display device using the voltage amplifier

An amplifying circuit for a liquid crystal display including a plurality of pixels, the amplifying unit comprising:

• an input unit, coupled between a first power source for supplying a first voltage and a second power source for supplying a second voltage, receiving a first input signal and a second input signal, and being controllable by the first and second input signals;
• a bias unit receiving a bias voltage for operating the input unit, and including a first node and a second node controlled by the input unit;
• and
• an output unit for applying an output voltage to a selected pixel by using a first output transistor being turned on/off according to a signal applied to the first node and a second output transistor being turned on/off according to a signal applied to the second node, the second output transistor being different from the first output transistor,
• wherein the input unit includes:
• a first input transistor having a first terminal coupled to the first power source and being turned on/off according to the first input signal;
• and
• a second input transistor having a first terminal coupled to the first power source and being turned on/off according to the second input signal, the second input transistor being the same type as the first input transistor, wherein the bias unit includes:
• a first transistor controlled by the on/off state of the first input transistor;
• and
• a second transistor controlled by the on/off state of the second input transistor,
• wherein the bias unit includes:
• a third transistor having a first terminal coupled to a first terminal of the first transistor and being turned on/off according to a third bias voltage;
• a fourth transistor having a first terminal coupled to the first terminal of the first transistor and being turned on/off according to a fourth bias voltage;
• a fifth transistor having a first terminal coupled to a first terminal of the second transistor and being turned on/off according to the third bias voltage;
• a sixth transistor having a first terminal coupled to the first terminal of the second transistor and being turned on/off according to the fourth bias voltage;
• a seventh transistor having (a) a first terminal coupled to a second terminal of the third transistor and also to a second terminal of the fourth transistor, and (b) a second terminal coupled to the second power source;
• and
• an eighth transistor having (a) a gate electrode coupled to a gate electrode of the seventh transistor and (b) a first terminal coupled to a second terminal of the fifth transistor and also to a second terminal of the sixth transistor, and
• wherein the output voltage is applied to the input unit, such that one of the first and second input signals is equivalent to the output voltage.