LMQ66430-Q1: tEN value

Hello Shinji,

Our stuff supporting this device are currently on public Holiday today, please give us a day to respond.  Thanks.

David.

Hi Baba-san,

I would like to follow up this quetion. 

regards,

Hello Shinji-san,

I have followed up with the right folks on my end, they will be here to help very shortly.  Sorry for the delay.  Thanks for your patience.

David.

Hello Shinji-san,

Sorry for the delay. It just got my attention today.   

We do not have the full characterization data about the the timing from EN=High to the 1st switching pulse, but the design typical value is 1ms.  I need to check with our design team to find out if the min and max delay time is available.  With get back to you in a couple of days.

Thanks,

Youhao

Hello Shinji-san,

Just let  you know I haven't forgotten this and we are still working on this. Hopefully to get you the answer soon.  I will post it here as soon as I received the answer.

Thanks,

Youhao`

Hello Shinji-san,

Sorry for the delay.  I got our design team's answer.  The time delay from EN high to the 1st switching pulse is within the range from 0.5ms to 1ms.  It was guaranteed by design.

Regarding the Datasheet Figure 8-4, our design team believe the input voltage may have a slow ramping up, introducing additional delay time to the startup process.  If the VIN is already there then pull up EN pin, the delay time should be up to 1ms.

Hope this clarifies.

Thanks,

Youhao

Hi Youhao-san,

Even if VIN is applied and then EN is powered up, tEN time is >2ms. It seems tEN time doesn't includes Vcc start up time. 

regards,

Hi Shinji-san,

I think you are right that it does not include VCC startup time. 

Thanks,

Youhao

Hi Youhao-san,

In that case, could you advise the Vcc turn on time?

Is there fixed soft start time?

I would like to know the min and max Vcc turn on time with given Vcc bypass cap. 

regards,

Hi Shinji-san,

Let me check with the design team.  

Thanks,

Youhao