TPS62363: voltage step in output consulting

Shuang Feng76

Expert 3060 points

Part Number: TPS62363
Other Parts Discussed in Thread: TPS62864, TPS62866

Hi,

Could you please help for below question about TPS62363.

Below figure is on the page 15 of the datasheet of TPS62363.
Why there is a voltage step on Vout? Could you please help to explain the root cause.
Why there is a current step on inductor current

over 2 years ago

0 Febin over 2 years ago

TI__Mastermind 19370 points

Hi Shuang,

Let me review this and I will provide a feedback tomorrow.

Regards,

Febin

0 Febin over 2 years ago in reply to Febin

TI__Mastermind 19370 points

Hi Shuang,

As seen from the d/s,

During soft start, the output voltage is monotonically ramped up to the minimum programmable output voltage. After reaching this threshold, the output voltage is further increased following the slope as programmed in the ramp rate settings until reaching the programmed output voltage. Once the nominal voltage is reached, regular operation as described above will continue.

So the steps in Vout are nothing but the typical behavior of this device.

I hope this helps!

Regards,

Febin

0 Shuang Feng76 over 2 years ago in reply to Febin

TI__Expert 3060 points

Hi Febin,

How about the current?

As i understand, after SS, it should directly change into ramp rate increasing status. Why there is a step?

Does this step cause current drop?

Hope for your clarify.

Thanks a lot.

0 Febin over 2 years ago in reply to Shuang Feng76

TI__Mastermind 19370 points

Hi Shuang,

As I explained, the SS has two steps: monotonic ramp to minimum output voltage and then ramp up to programmed nominal output voltage. Due to this, the inductor current charges and discharges and that is seen in the waveforms. The startup waveforms are varying based on Vin, Vout, Load, and you can see that in figures 18-21.

The steps that you see are dependent on the Vout and load conditions and is the typical behavior of this device. This will not cause any additional current drop.

Also, I would like to propose some newer alternatives like TPS62864 or TPS62866.

https://www.ti.com/lit/ds/symlink/tps62864.pdf

Regards,

Febin

0 Shuang Feng76 over 2 years ago in reply to Febin

TI__Expert 3060 points

Hi Febin,

thanks a lot for explaination.

Could I get your full name? Due to this case i need to transfer it into internal discussion.

I need to send you email for future supporting.

0 Febin over 2 years ago in reply to Shuang Feng76

TI__Mastermind 19370 points

Hi Shuang,

I send you an email now.

Regards,

Febin

+1 Febin over 2 years ago in reply to Febin

TI__Mastermind 19370 points

Hi Shuang,

As we have taken this discussion offline, I will close this thread. Hope you're fine that.

Please hit Resolved if you agree.

Regards,

Febin

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TPS62363: voltage step in output consulting