| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a constant voltage power circuit improving a transitional response lag of an output transistor without increasing current consumption and having small fluctuated output voltage. <P>SOLUTION: When output current Io is rapidly changed and a response lag occurs in a power transistor 7 and a difference between the output voltage Vp1 at a first driver stage 102 and the output voltage Vp2 at a second driver stage 103 satisfies an expression (Vp1-Vp2)>¾Vtp¾ if a threshold value of a P-channel MOS type field-effect transistor 15 for a control circuit is assumed to be Vtp, the P-channel MOS type field-effect transistor 15 for a control circuit turns on, a route where a gate of the power transistor 7 is connected with the ground is formed via the P-channel MOS type field-effect transistor 15 for a control circuit, and a parasitic capacity of the power transistor 7 is rapidly discharged, and consequently, the transitional response lag is dissolved. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
