| 摘要 |
PURPOSE:To prevent a constant-current output from being generated,until it reaches a stable operating condition, by connecting an emitter of a second NPN transistor to a cathode of a Zener diode. CONSTITUTION:An emitter of the second NPN transistor 5 is connected to a cathode of a Zener diode 6. Accordingly, even if a current tries to flow into the transistor 5 through a transistor 7 of a second mirror circuit 40, no current flows until the power source Vcc voltage exceeds a Zener voltage Vz of the Zener diode 6, and a constant-current output is not generated until the power source voltage reaches a voltage which becomes a stable operating state. Therefore, a malfunction of the post-stage of this circuit can be prevented.
|
