TPS25947EVM: Please help with countermeasure

Hi N.Z. ,

Sorry I did not get your question? What has short circuited on board? Did it happen accidentally or you have intentionally failed as a test conditon?

Regards

Kunal Goel

Hi Kunal,

Sorry for the lack of explanation.

I didn't know which one of the component is short circuited. When tested, Ch1 did have the appropriate value for Vin but for Vout the value is lesser than it's supposed to be. I am guessing it's short circuited. I did modify the circuit by desoldering R1 from the board.

I also tested other components aside from the eFuse with voltmeter to see if they aren't functioning, but they were fine. I couldn't figure out how to test if the eFuse is functioning or not. Could you tell me the way to test?

Hi NZ,

Have you connected any load at output? How much is VIN and VOUT? You can remove eFuse from PCB and measure impedance between its pins VIN-VOUT,VIN-GND,VOUT-GND. Also you can measure impedance on PCB pads for this device. 

But one thing if you desolder R1 device will disable, EN pin will be GNDed. Any other modification you did?

Do you have any waveform showing VIN,VOUT,EN?

Regards

Kunal Goel

Hi Kunal.

I connected Vin=12V, but the output becomes Vout=~2V. I didn't have the waveform saved on my PC. Also, no load at the output when measuring.

Kunal Goel said:

But one thing if you desolder R1 device will disable, EN pin will be GNDed. Any other modification you did?

Oh I see. 

I did connect it to the R25 of the Ch2. I also desoldered R25 for Ch2.  

Kunal Goel said:

You can remove eFuse from PCB and measure impedance between its pins VIN-VOUT,VIN-GND,VOUT-GND. Also you can measure impedance on PCB pads for this device

Thank you for this advice. I will try it!

Hi NZ,

So you removed R1 and R25 both during testing?

Regards

Kunal Goel

Hi Kunal,

Yes. That's the only modification for EVM.