Patent ID: 6316999
Filing Date: 2001-11-13
Classification: H03F

Abstract:
An operational amplifier comprising an output stage for outputting an output signal in response to an input signal, wherein;said output stage performs a push-pull operation respectively in response to a plurality of specific signals generated on the basis of said input signal and has a plurality of output stage transistors for generating said output signal as a result of said push-pull operation, andsaid plurality of specific signals are generated as signals being substantially equal to each other in delay time until said plurality of specific signals are inputted respectively into said plurality of output stage transistors,said output stage is provided with a specific signal generating means for generating said plurality of specific signals on the basis of said input signal, and an output stage having said plurality of output stage transistors, wherein; said specific signal generating means is provided with;a first transistor which has a control electrode to have said input signal inputted and which is connected between a first power source terminal and a second power source terminal,a first constant current source connected in series with said first transistor between said first power source terminal and said second power source terminal,a second transistor whose control electrode is connected to the connection point of said first transistor and said first constant current source, and which is connected between the connection point of said first transistor and said first constant current source, and said second power source terminal,a third transistor whose control electrode is connected to the connection point of said first transistor and said first constant current source, and which is connected between said first power source terminal and said second power source terminal,a second constant current source connected in series with said third transistor between said first power source terminal and said second power source terminal,a fourth transistor whose control electrode is connected to the connection point of said first transistor and said first constant current source, and which is connected between said first power source terminal and said second power source terminal, anda third constant current source connected in series with said fourth transistor between said first power source terminal and said second power source terminal.