| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a triangular wave generator capable of setting an upper-limit voltage and a lower-limit voltage of a triangular wave without rapidly charging/discharging a capacitor while being synchronized to an external synchronizing signal. <P>SOLUTION: In a triangular wave generator (100), a charging/discharging circuit (20) charges/discharges a capacitor (10) with a prescribed current in accordance with a given instruction. An upper-limit detector (30) and a lower-limit detector (40) detect that a voltage of a triangular wave is higher than the upper-limit voltage and lower than the lower-limit voltage. A synchronization detector (50) detects that the external synchronizing signal is shifted from a first logic level to a second logic level. When there is detection due to the upper-limit detector (30), a control circuit (60) instructs discharging to the charging/discharging circuit (20) and when there is detection due to the lower-limit detector (40), on the other hand, the control circuit (60) instructs charging to the charging/discharging circuit (20). Further, when there is detection due to the synchronization detector (50), the control circuit instructs either discharging or charging to the charging/discharging circuit (20). <P>COPYRIGHT: (C)2009,JPO&INPIT |
