TPS62160: Output voltage is different from one part to another

Zakaria ElKhachin

Part Number: TPS62160

Hi,

I am designing a 3.6V converter with VIN= 5.5V based on the TPS62160. After producing the board and measure on it, I get a lower voltage than excpected. There is a 600mV difference and this difference gets higher with every batch produced. The FB resistors have 1% tolerances with values not so big to impact the FB accuracy: on the range of 15k as max values.

Do you have any ideas on what might cause this problem?

Thanks in advance for the help?

/Zakaria.

over 1 year ago

0 Nancy Zhang over 1 year ago

TI__Mastermind 45820 points

Hi Zakaria,

I think it is caused by flux contamination. Please try to deep clean the board. Usually I drop the board to an ultrasonic cleaner for 15min with 60 degree heat. See the ultrasound cleaner as below.

Hope this helps,

Thanks,

Nancy

0 Zakaria ElKhachin over 1 year ago in reply to Nancy Zhang

Prodigy 20 points

Hi Nancy,

I have many converters on the board that has accurate voltage outputs. So if it was a flux contamination, I would expect something similar to happen to them. Plus the board production site already uses this method.

/Zakaria.

0 Shuai Fan over 1 year ago in reply to Zakaria ElKhachin

TI__Genius 12981 points

Nancy will reply you tomorrow!

Shuai

0 Nancy Zhang over 1 year ago in reply to Shuai Fan

TI__Mastermind 45820 points

Hi Zakaria,

Understand,

1. Did all the TPS62160 on the board have same behavior? or different with some higher or some lower?

2. Did you measure the FB pin voltage with 0.8V typ on the board?

3. It is worthy to try to clean FB area with alcohol deeply.

4. Could you send us the schematic and layout file? So we can check if FB coupled any noise?

Thanks,

Nancy

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TPS62160: Output voltage is different from one part to another