TPS54061: TPS54061 ocp behavior

Shaquille Chen

Intellectual 1770 points

Part Number: TPS54061

Hi Team,

Customer have some question about TPS54061 OCP behavior.

Test condition:

VIN = 24V, Iload = 0.1A ~ 0.4A. T = 1ms, 50% duty, slew rate : 32mA/us

Questions:

1.When the output load are 0.1A, why device stop switching?

2. The waveform shown sw node switching but output drop. Any possible reason?

Waveform:

Shaq

over 5 years ago

0 Ankit Gupta95 over 5 years ago

TI__Expert 4555 points

Hi Shaq,

Can you please share your schematic and layout for review.

Thanks,

Ankit

0 Shaquille Chen over 5 years ago in reply to Ankit Gupta95

TI__Intellectual 1770 points

Hi Ankit,

This is EVM which change output from 3.3V to 5V.

You can see similar result at your side.

Shaq.

0 Ankit Gupta95 over 5 years ago in reply to Shaquille Chen

TI__Expert 4555 points

Hello Shaquille,

I am not understanding the waveforms here, or it is not very well annotated.

What are the green and purple waveform?

Exactly at what instant Vout-to-ground short is applied?

What is the Vout voltage?

While short is applied, the inductor current should hit the part's peak current limit. I am not seeing that?

How short is applied, is it a hard short with the screwdriver, or soft short?

Please annotate the waveform in more detail to understand the issue.

Best Regards,

Ankit Gupta

Application Engineer

0 Shaquille Chen over 5 years ago in reply to Ankit Gupta95

TI__Intellectual 1770 points

Hi Ankit,

The different waveform with different color label.

CH1: Iout (blue)

CH2: SW ( green- blue)

CH3: Vout ( purple )

CH4: IL (Green)

The test condition already shown. Not short to GND.

0 Ankit Gupta95 over 5 years ago in reply to Shaquille Chen

TI__Expert 4555 points

Can you please schedule a phone call to discuss about this issue, I have few questions to understand this issue completely.

email id: a-gupta1@ti.com .

Best Regards,

Ankit Gupta

Application Engineer

0 Ankit Gupta95 over 5 years ago in reply to Ankit Gupta95

TI__Expert 4555 points

Shaquille,

It is been a while we haven't heard back from you. I am closing this thread for now, please let TI know if you need more assistance. Thanks!

Best Regards,

Ankit Gupta

Application Engineer

Power management

Power management forum

TPS54061: TPS54061 ocp behavior