------Question for NCP4307FBSNT1G Please Put your question below------
for the Onsemi NCP4307 versions which specific versions have a active High pin and which ones have active low. the OPN table in the datasheet did not tell me.
Hi tn3214890,
Welcome to the TechForum.
From the OPN Coding table:
So, here’s the function of the TRIG/DIS pin:
NCP4307FASNT1G Active High
NCP4307FBSNT1G Active High
NCP4307AASNT1G Active High
NCP4307WASNT1G Active Low
2 Likes
Hello thank you for the reply. I used NCP4306 for DCM. It works very well.
But it has problem with CCM mode. someone from onsemi said, For CCM use NCP4307 chip.
I used NCP4307 WA version. But the trigger output is active low.
I used NCP4307 AA version for Active Clamp Flyback. But I got very short gate pulse at the beginning of secondary FET is on.
Why don’t I have a full gate pulse? I even tied the trigger pin to GND, and it is still short pulse at the beginning.
I even tied the Trigger pin to GND, and it generates a very short pulse.
Please help me understand why this might be.
Please give me example circuits that uses primary gate signal to control the secondary Trigger pulse.
Give me the contact person who can help me. I am working for Big company in Europe
We are researching an answer and will get back to you as soon as possible.
It is difficult to offer comment without a thorough understanding of the circuit being used, the circuit layout, operating conditions, example waveforms, etc.
This said, page 20 of the datasheet contains a discussion of parasitic circuit elements and their effects, which may potentially contribute to early turn-off of the synchronous rectifier under control.
1 Like