| 摘要 |
PURPOSE:To improve the dependability upon a power supply voltage while preventing the resultant oscillation from occuring by a method wherein a relatively large condenser for eliminating power supply is provided to the output while another condenser for phase compensation is added to a feedback loop comprising MOSFETs of current mirror type that make bias current flow through MOSFETs. CONSTITUTION:A condenser CL with relatively large capacity is provided between a source of MOSFET Q4 and a ground potential point of circuit. However, in order to fix the source potential of MOSFET Q4 by the condenser CL, if any phase conversion occurs in a feedback loop wherein the ripple content contained in power supply voltage Vcc is transferred to a gate of MOSFET Q4 to be further transferred to a drain and a gate of MOSFET Q1 through the intermediary of current mirror MOSFETs Q3, Q2, an unfavorable oscillation occurs. Therefore, the phase compensation is performed by providing a condenser C1 in the feedback loop, i.e., between the gate of MOSFET Q4 and the other gates of MOSFETs Q3, Q2.
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