LM20146: Start up waveform

Hello kura-san,

Could you also provide schematic used for this as well as the layout of your design?

Thank you!

Regards,
Dorian

Dorian-san

Thank you for your reply.

We got additional COMP waveforms from customer.

Please see attached.

COMP waveform.xlsx

We will send circuit information to you thru another mail.

Regards,

Hello kura-san,

Looking at the COMP waveform you send, Is there a difference in terms of setup, VIN/VOUT/load conditions between the abnormal and normal start up waveform?

Let me know once you have the circuit information available, Schematic and layout.

Thanks a lot!

Regards,

Dorian

Dorian-san

I have a question about COMP pin.

COMP voltage looks down suddenly.

Please let us know your idea what cause this COMP voltage down suddenly.

And Please let us know OVP behavior.when IC detect OVP,is COMP discharged ?

Hello kura-san,

The behavior of the device when OVP occurs is described in the datasheet in page 11 (Power Good and Over Voltage Fault Handling).

When OVP occurs, the Low-side MOSFET is turned on as long as the FB voltage is above the Vovp threshold.

As FB is internally connected with COMP through the error amplifier, COMP will follow FB if OVP occurs.

Do you have any more information regarding the schematic and Layout?
Thanks,

Dorian  

Dorian-san

Thank you for your support.

I sent private message with circuit information to you.Please check it.

About abnormal and normal start up waveforms I sent:

They got these wave forms with with same IC and same board.

Regards,