| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an oscillation circuit for reducing frequency variations in clock signal, resulting from the variation in the power supply voltage. <P>SOLUTION: The oscillation circuit concerning an embodiment includes a triangular wave generating circuit which generates triangle wave signal according to an output clock signal; a comparison circuit which generates a clock signal, according to the comparison of a reference voltage of the triangle wave signal, and a first and second reference voltages; a current adjustment circuit which adjusts the adjustment current value according to the supply voltage for the comparison circuit; and a reference voltage generating circuit which generates first and second reference voltages, having a voltage difference according to the adjustment current value. In the current adjustment circuit, the adjustment current is increased, when the power supply voltage for the comparison circuit increases; while the adjustment current is decreased, when the power supply voltage decreases. In the reference voltage generating circuit, the voltage difference between the first and second reference voltages is made large, when the adjustment current is increased; and the voltage difference is decreased, when the adjustment current is decreased. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
