TPS54260-Q1: Peak current issue of output

Jeffrey Chung1

Part Number: TPS54260-Q1
Other Parts Discussed in Thread: TPS54260,

Hi Richard,

Customer is verifying their board with TPS54260, but there is a peak current issue of around 3A on output. Schottky diodes(NRVTSS3100ET3G, NRVBS3200NT3G, NRVBS3100T3G) are verified on their board, but all results are same. Please check an attached waveform below and let me know the reason why.

Start-up waveforrm_TPS54260QDGQRQ1.pdf

Regards,

6 months ago

0 Ridge Lahti 6 months ago

TI__Genius 13825 points

Hello,

Can you share the schematic of the buck converter?

Best regards,

Ridge

0 Jeffrey Chung1 6 months ago in reply to Ridge Lahti

Expert 2745 points

Hi Ridge,

Please refer to the schematic of original post(TPS54260-Q1: How to choose a Schottky diode).

Regards,

0 Ridge Lahti 6 months ago in reply to Jeffrey Chung1

TI__Genius 13825 points

Hello,

The chosen inductance value seems large for this application. It looks like your switching frequency is around 400kHz. I calculated an inductor value of 20uH for your application requirements.

Also, your inductor has a saturation current of 4.5A. It is possible that the inductor is saturating at your condition, which would cause the buck converter to behave improperly. When selecting an inductor, the saturation current must be larger than the IC current limit threshold. For the TPS54260-Q1, the saturation current must be rated for 6.1A.

What are the conditions and expected load when you see this issue?

Best regards,

Ridge

0 Jeffrey Chung1 6 months ago in reply to Ridge Lahti

Expert 2745 points

Hi Ridge,

First of all, confirmed the input and output conditions of Vin=24V, Vout=12V. I will let you know the load current condition if I get it from customer.

Regards,

0 Ridge Lahti 6 months ago in reply to Jeffrey Chung1

TI__Genius 13825 points

Hello,

Please update this thread when you receive the load information.

Best regards,

Ridge

0 Ridge Lahti 5 months ago in reply to Ridge Lahti

TI__Genius 13825 points

Hello,

Since we have not heard back in a while, I am going to close this thread. If you have more questions, you can reply to this thread or open a new one.

Best regards,

Ridge

0 Jeffrey Chung1 5 months ago in reply to Ridge Lahti

Expert 2745 points

Hi Ridge,

I didn't get the information from customer until now, so I will open a new thread if I get it. Thanks for your support.

Regards,

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TPS54260-Q1: Peak current issue of output