Why does the UC3843 drive MOS tube have a waveform only in a few cycles, but not at other times?
I now use UC3843 to control the MOS tube to make a boost circuit. After measuring the output waveform of pin 6 of UC3843, I find that there are only a few cycles of waveforms, and the output waveforms are always low at other times. 24VDC is boosted to 120VDC, 0.25A, and the switching frequency is 220K. why is this happening?
Introduction of UC3843: https://www.utmel.com/components/uc3843-pwm-controller-pinout-datasheet-and-uses?id=388