| 摘要 |
PURPOSE:To always keep a prescribed delay time without being affected by the fluctuation of a power voltage by supplying a prescribed voltage of a con stant voltage generating section as a power supply of a delay circuit section. CONSTITUTION:A constant voltage generating section 1 consists of series connec tion of a resistor R11 and diodes D11-D18, and since the forward on-voltage of one of the diodes D11-D18 is nearly 0.8V, a potential difference of nearly 4. 0V is generated across the series connection circuit of the 5 diodes D11-D18. That is, an output voltage Vp of the constant voltage generating section 1 is nearly 4.0V, and even if the power voltage Vcc is fluctuated from, e.g., 4.5V to 5.5V, the output voltage Vp is always as nearly 4.0V. Thus, the power voltage fed to a delay circuit section 2 is always kept to nearly 4. 0V independently of the fluctuation of the power voltage Vcc and the value of the on-resistance of MOS transistors(TRs) QP12, QP13, QN12, QN13 being components of the delay circuit section 2 is kept nearly constant. Thus, a constant delay time is always kept independently of the fluctuation of the power voltage Vcc. |
