Undervoltage shutdown circuit for SMPS

[pona]

Hey everybody,
I want a simple undervoltage shutdown circuit with design for SMPS.

 

[Tahmid]

Hi,
Here is a circuit that I believe should serve your purpose. The circuit will carry out undervoltage shutdown at V= Zener voltage + 0.6v (for transistor base). So, if you have a 3.9v zener, it will give you undervoltage cut at 4.5v, 4.3v zener at 4.9v, 11v zener at 11.6v and so on.

Hope this helps.
Tahmid.

 

[bobcat1]

Hi

Use a resistor divider on the SMPS CE(Chip Enable) pin (resistor from Vin to CE pin and resistor from CE pin to GND also add zener diode to protect CE pin from over voltage

All the best

Bobi