TPS5410: Power ON issue

Hi

have you try to power on and off the TPS5410 only by other 24Vdc souce, and what's the result?

you can also monitor the waveform of PH and ENA see the waevform when you power up and power down see .

Thanks

Hi Daniel,

We have tested on 24VDC, and we haven't face this issue. Thi issue occurs only on the field, and we don't have a timeline when the power goes and come back. So, we can't monitor PH and ENA waveform.

Do you see anything wrong with the design? What could be creating an issue here?

Mrudang

Hi 

is it 100% or partial of the product have the issue?  I didn't see the issue from schematic, if you can measure the votlage by voltagemeter , you can check EN votlage when 24V is applied. 

Thanks 

Ho Daniel,

Is there any issue with compensation network calculations, AL-EL capacitor on the load side for device stability in our intended use case? We have observed this issue in the field only not during in-house testing.

Can I have a call with you for a use-case application and a better understanding?

Mrudang

+91 99252-20048

HI

if the compensation or loop issue, it will be found when you use 24V DC souce , the loop won't change by input souce change, but 

1. the AL-EL capacitance will chagne a lot by temperature.

2. Input impedance of TPS5410 need to match the output impedance of 24V DC souce to avoid the input resonant by unmatched impedance of input and output. but it will be easily solved by add a AL-EL cap at input.

if no waveform to identify the issue, it will be hard to guess the root cause of the issue.

Thanks 

Hi Daniel,

I have few queries, kindly provide your valuable response. 

1. We do not think that impedance mismatch for o/p and i/p for 24V, as we have measured 24V at i/p side. What value you suggest to add a capacitor on i/p side? 
2. Can we add a pull-up resistor 10K with 5V on the EN signal? Will it help us?
3. It's been 4-5 yrs the device is installed on-field and after 4-5 yrs of running condition, the issue has occurred the first time and repeat thereafter. Is it possible to have any MTBF effect on 3.3 output IC (U2 only) only due to switching i/p power ON/OFF from the grid power side? I believe it should impact both U2 and U3. Please confirm.
4. Is it any issue with generating the 3.3V from 24V using the TPS5410 IC?
5. What exactly you would like to capture on the oscilloscope and how it will help us? If you want we can capture the voltage value using DMM.

Mrudang

Hi Daniel Li14,

Have you got a chance to go through my few queries in the previous response?

Mrudang

HI

1. suggest add a 47uF 50V AL

2. yes, you can try , at least you can check whether it is ENA issue.

3 If the problem is only happened after 4-5yr use, my question is this issue is 100% happen or it failed in very limited number? As I recommend before, pls help to catch the issue waveform including the PH, VO and EN. DMM can only check the EN, VO voltage, no help for PH. One more thing is whether change the new silicon can fixed this issue?

4. I don't see the issue from you schematic.

pls refer 3.

Thanks

HI Daniel,

Thanks for the response. I will check, test and update you soon.

Mrudang

Hi

Thanks, waiting for your update

HI

I didn't see the update, I will close this question, you can reopen it if you need

Thanks