| 摘要 |
PURPOSE:To make large current driving possible while keeping a high-precision voltage level in an output and integrate a circuit by using the connection part between a CMOS transistor(TR) and a resistance as the output of an operational amplifier and storing this circuit in the same integrated circuit. CONSTITUTION:A one-channel TR of only P channel or N chanel is used as the TR in the output stage of the CMOS operational amplifier, and the resistance is used for the purpose of enhancing the driving capability. This resistance is used for normal operation of the MOS TR, current limiting, and stable operation of the whole of the circuit in case of a buffer constitution. Further, this resistance does not require a high precision and can be formed in a semiconductor by a CMOS process. The gain in the output stage constituted with the resistance and the MOS TR is 1-5 times as high as that of the CMOS operational amplifier, and the break frequency is very high incomparison with the CMOS operational amplifier, and therefore, oscillation is not generated even in case of the buffer constitution if the CMOS operational amplifier in the preceding stage has such degree of phase margin that it is not oscillated itself. |
