LOW POWER CONSUMING TRIANGULAR WAVE GENERATING CIRCUIT

PURPOSE:To obtain a low power consuming triangular wave generating circuit by providing in a triangular wave generating circuit with a 2nd constant current triangular wave circuit for discharging having a constant current value greater than that of a first constant current circuit for charging a capacitor, and a 3rd constant current triangular wave circuit for discharging having a constant current value sufficiently greater than that of the 2nd constant current circuit. CONSTITUTION:The 1st constant current circuit 11 for charging a capacitor 10, the 2nd constant current circuit 12 having a constant current value greater than that of the 1st constant current circuit 11 for discharging, and the 3rd constant current circuit 13 having a constant current value sufficiently greater than that of said 2nd constant current circuit are provided in a triangular wave generating circuit. Further, when the output level during discharging the triangular wave drops below a predetermined value, the 3rd constant circuit 13 is shut off. In such a way, discharging by the 3rd constant current circuit 13 for sharp grade discharging can be carried out only for a short pulse period of time, thereby shorten a period of time for consuming large current.