condition of enable pin when its left floating

[Shifali15]

Hi,

What will be the condition of enable pin in EN5339QI if its left floating

[Mostafa_Intel_AE]

Hello @Shifali15 ,

If EN pin left floating this will cause the part to be off, but there is a chance that the part could startup under that condition if there is any voltage charge (due to any electrostatics) higher than 0.4V on that pin.

Thanks,

Mostafa 

[Shifali15]

Hi Mostafa,

Thankyou for your response. Attached is my layout design. Kindly review the same and provide your valuable feedback.

[Mostafa_Intel_AE]

Hi @Shifali15 ,

So sorry for late response, I have reviewed your layout and looks okay.

I would recommend inserting 10Ohm between AVIN and PVIN.

Also please help to confirm if Enable is connected to AVIN or you are using external signal to trigger the Enable pin.

Thanks,

Mostafa

[Shifali15]

Hi Mostafa,

Thankyou for your response.

I am using external signal to trigger the enable pin.

Also can you let me know the significance of adding this 10ohm resistor.

[Mostafa_Intel_AE · Accepted solution]

Hello @Shifali15 ,

The 10R will help to delay the AVIN ramping from the PVIN during the start up and shutdown and this will help to avoid the UVLO to trigger during the startup incase of the noisy PVIN.

Thanks,

Mostafa