Dir Sir/Madam, We used TNY278GN for a three phase power supply. During the tests using Zener diode as reference in the feedback, the drain voltage is normal; you can find them in fig.1, attached.
Using TL431 as reference in the feedback, the drain voltage is an on/off as shown in fig.2. Enable pin voltage is in the same state. In the on state the drain voltage seems to be working normal fig.3.
- Please let me know whether it is ok and due to the TL431 on/off characters.
- In case it was ok, please let me know whether using TL431 may affect the SMPS lifetime.
Looking forward to hearing from you. Regards