PTH08T240W: The output of PTH08T240W is 0 V

Jerry Yang48

Part Number: PTH08T240W

Hi:

The normal output of PTH08T240W is 1.2V, but due to the short circuit of 10uF load capacitor at the output end, after replacing the new load capacitor, PTH08T240W can output 1.2V normally. But after a period of operation, the output becomes 0V. I see PTH08T240W has the function of current protection. I wonder if the short circuit of load capacitor will damage the function of PTH08T240W. Is there any good solution? Thank you very much.

over 5 years ago

0 Jimmy Hua over 5 years ago

TI__Guru 50120 points

Hi,

Let me take a look into this and get back to you.

Regards,

Jimmy

0 Jimmy Hua over 5 years ago in reply to Jimmy Hua

TI__Guru 50120 points

Hi,

Can you provide a schematic for me to review? The overcurrent protection is meant to shut the regulated output when a load the exceeds the overcurrent threshold is applied. I don't think shorting the output should damage the power module.

How often do you experience this issue where you get 0V after some time of operation. How many boards have this failure event? How long does it take before the output voltage drops from 1.2V typical to 0V? Is there anything downstream that perhaps is causing the output to be pulled low?

Regards,
Jimmy

0 Jimmy Hua over 5 years ago in reply to Jimmy Hua

TI__Guru 50120 points

Hi,

Can I get an update on this?

Regards,
Jimmy

0 Jimmy Hua over 5 years ago in reply to Jimmy Hua

TI__Guru 50120 points

Hi,

I haven't heard back from you for a while. Because of this I am assuming you were able to resolve the issue on your end and I will be closing this thread. If you have any further questions simply reply in this thread and it should reopen so we can continue troubleshooting the issue.

Regards,

Jimmy

0 Jerry Yang48 over 5 years ago in reply to Jimmy Hua

Intellectual 640 points

this is sch.

0 Jimmy Hua over 5 years ago in reply to Jerry Yang48

TI__Guru 50120 points

Hi Jerry,

The overall schematic looks okay for a 1.2V output.

For the TurboTrans component selection, with a total Cout of 801uF, equation 2 of the datasheet yields a Rtt value of 2.65kOhm. The nearest 1% resistor value would be 2.67kOhm. I would suggest changing the Rtt value based on equation 2 in order to optimize load transients and stability.

Is the 10uF load capacitor also included in this schematic? I can't see how adding an extra 10uF capacitor to the schematic will short the output. Can you clarify?

Regards,

Jimmy

0 Jerry Yang48 over 5 years ago in reply to Jimmy Hua

Intellectual 640 points

wait ! I ask my customer to check it out .

0 Jimmy Hua over 5 years ago in reply to Jerry Yang48

TI__Guru 50120 points

Hi Jerry,

You can email me directly at j-hua@ti.com for continued support on this matter. I will be closing this thread for now.

Regards,

Jimmy

Because of the Thanksgiving holiday in the U.S., TI E2E™ design support forum responses may be delayed from November 25 through December 2. Thank you for your patience.

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PTH08T240W: The output of PTH08T240W is 0 V