TPS62842EVM-103: When outputting with load, the input voltage fluctuates

Chen Colin

Prodigy 130 points

Part Number: TPS62842EVM-103

Test conditions: Input 6V, output 3.6V, with a load current of 15mA

Result: The input voltage fluctuates; Under no-load conditions, the input voltage is stable

Could you please help determine the reason? Looking forward to your reply. Thank you

3 months ago

0 Moheddin Pasha Shaik 3 months ago

TI__Genius 14010 points

Hello Colin,

Thank you for reaching out,

Can you please provide me your measurement setup?

I would recommend to measure across the input capacitor using tip and barrel method.

How to measure ripple for better design outcomes (ti.com)

This might be also due to electrolytic capacitors which has high ESR.

Thank you & regards,

Moheddin.

0 Moheddin Pasha Shaik 3 months ago in reply to Moheddin Pasha Shaik

TI__Genius 14010 points

Hello Colin,

Do you have any updates?

Thank you & regards,

Moheddin.

0 Chen Colin 3 months ago in reply to Moheddin Pasha Shaik

Prodigy 130 points

Hi Moheddin,

Thank you for your reply.

I haven't received any feedback from the customer yet. After communicating with them earlier, I suspected that it was due to insufficient driving capacity of the customer's previous 6V power supply output. The customer's previous 6V voltage came from four 1.5V alkaline batteries. I have suggested that the customer use a DC power supply for testing, but I haven't received any feedback yet

+1 Moheddin Pasha Shaik 3 months ago in reply to Chen Colin

TI__Genius 14010 points

Hello Colin,

If you don't have any further questions, can you please close the thread by clicking on Resolved.

Thank you & regards,

Moheddin.

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TPS62842EVM-103: When outputting with load, the input voltage fluctuates