| 摘要 |
PURPOSE:To obtain a square wave signal in a low frequency of about several kHz comparatively stably against temperature fluctuation, by connecting a charge/discharge circuit to a gate of two inverters. CONSTITUTION:A capacitor 5 and a transistor TR4 of constant current operation are combined to form the charge/discharge circuit 6, and an output of the circuit 6 is connected to the gate of the two inverters 9 and 10. The frequency (f) of the square wave is expressed as f=Id/(C.VG9), where Id is the constant current value of the TR4, C is the capacitance of the capacitor 5, and VG9 is the logic level of the inverter 9. For example, Id=10<-9>A, C=10<-12>F and VG9=1V are selected. Those values are possible for realization sufficiently without increase in the occupied area. The (f) in this case is about 1kHz. Since the duty ratio is determined almost with the ratio of VG9 to VG10 (logic level of the inverter 10), the control is done with good accuracy by using the ion implantation technology. |
