| 摘要 |
<p>PURPOSE: To suppress the frequency fluctuation of a clock signal obtained from the oscillation circuit even in the case of occurrence of fluctuation of a power supply voltage or of dispersion in components of the oscillation circuit provided in an integrated circuit in the case of manufacturing the semiconductor integrated circuit. CONSTITUTION: When an output voltage from a comparator 13 is Vss, a PMOS transistor(TR) 16 is conductive and a constant currentΔI in response to the potential difference between a power supply voltage Vdd and a reference voltage flows to the PMOS TR, a resistor 18 and an NMOS TR 21. A capacitor 9 is discharged through an NMOS TR 25 by a constant currentΔI attended therewith, and when an NMOS TR 17 is conductive with the output voltage of the comparator 13 reaching a voltage Vdd, a constant currentΔI in response to the potential difference between a ground level voltage and the reference voltage is supplied to a PMOS TR 20, the resistor 18 and the NMOS TR 17. Thus, a capacitor 9 is charged by the constant currentΔI flowing to the PMOS TR 24.</p> |
