| 摘要 |
<p>PURPOSE:To obtain the output of a sawtooth wave whose falling period and DC voltage are constant by providing two comparators or more. CONSTITUTION:When a pulse is inputted to a pulse input terminal 2, it is fed to the base of a transistor(TR) 4 and the TR 4 is disconnected for a pulse period T1. When the voltage at a sawtooth wave output terminal is larger than the base voltage of a TR 19 of a comparator 38, a TR 20 is disconnected and a TR 8 is disconnected. Thus, the TR 7 is saturated. A reference power supply 34 is connected to the base of the TR 11 of the comparator 37 and the current of a constant current source 12 flows to the collector of the TR 11 by selecting the DC voltage to a proper value, inputted to a current mirror circuit 40 and outputted from the collectors of the TRs 14, 15. The current flows from the TR 14 to a resistor 29 and the base of the TR 9, which is saturated. The current of the TR 15 is inputted to a current mirror circuit 41, subject to mirror comparator by the TRs 30, 31 and outputted as the collector current of the TR 30. Thus, the sawtooth wave whose falling period and DC voltage are constant is generated independently of a pulse input period.</p> |
