Undervoltage and Overvoltage lockout

Posted by: vintch on 07/20/2011

Hi.

Tell me please, is there some techniques to configure UV/OV lockout feature for that parameters:
UV threshold - 340-360 VDC
OV threshold - 420-440 VDC
?

Device: TOP258YN

I tried to combine resistors and zener diodes, but I can't find solve of this problem.

Thanks for your attention.

Comments

Now I've designed a circuit with an additional analog comparator (LM393).
(look at attachment. Sorry for image quality)
Actually it works fine. Without hysteresis, but it is not necessary.
But it is strange a little, to use an additional IC with an integrated PWM controller to implement so "small" function. Is there some "typical" techniques to solve this problem?

Since there is a locked ratio between UV and OV and is much wider than what you want you will need to create a seperate detector for OV which should have an output to force L pin current above OV threshold

I came to the same conclusion.
Thank you.