Hello,
I had posted a same question earlier, but have been evaluating another circuit for a while and have not gotten around to this.
My sincere apologies for not responding to Mr.Stefan's reply.
I will post it again and would appreciate your advice.
Because the RT pin did not move as set, the potential difference between RT and AGND was measured.
As I mentioned before, this problem is seen early in the operation.
It was found that the RT voltage swung upward at the falling edge of the GATE pin (Figure 1).
However, this is a noise that can be seen even when the RT is operating as configured, as shown in Figure 2.
It is not known if the problem is caused by this noise.
The application note says "The RT pin is regulated to 0.5 V by the internal RT regulator when the device is enabled.".
If the RT pin has a higher potential than 0.5V, how does the frequency change?
Is there anything else I should look at to investigate this problem?
Best regards,
Katsuya
