OUTPUT BUFFER AND POWER AMPLIFIER COMPRISING THEREOF

摘要

An output buffer and a power amplifier including the same are provided to obtain swing range of wide output voltage by maintain low output impedance in a high frequency band. A push-pull circuit unit(10) comprises transistors connected between power supply voltage of the high level and power supply voltage of the low level in the form of a push-pull. An output unit(32) comprises common sources connected between the power supply voltage of the high level and the power supply voltage of the low level. An output bias unit(51) biases the output unit. According to signals from the push-pull circuit unit, a driving unit(22) operates the output unit. According to the input voltage, a rail-to-rail controller(40) controls on-off of the transistors included in the push-pull circuit unit. Therefore, the swing range of the output voltage widens.