TPS82130: TPS82130 EN defect

wolfgang kopp

Part Number: TPS82130

Dear TI Community,

we use the TPS82130 in some designs, but now we face a new problem. The EN pin have a low input resistance (50-100R) all of a sudden on some parts.

The EN pin is connected to VIN with a resistor (10k) and a 100nF cap to GND. There are different values to achieve the right power up sequence.

Good devices have 12V on the EN pin after power up, bad ones less than 0,3V.

Do you have any ideas?

BR,

Wolfgang

over 6 years ago

0 Omar Hegazi over 6 years ago

TI__Intellectual 1780 points

Dear Wolfgang,

I am not sure I understand your design. Can you share the schematics here?
What do you mean by using different values to achieve the power up sequence?
And where are you measuring the 12 and 0.3V exactly?

Best regards,
Omar

0 wolfgang kopp over 6 years ago in reply to Omar Hegazi

Intellectual 450 points

we use 8pcs of the TPS for different voltages. See the part of the schematic for more details. Hope that its more clear now.

0 Omar Hegazi over 6 years ago in reply to wolfgang kopp

TI__Intellectual 1780 points

Hi Wolfgang,

Thanks for attaching the schematics.
There are differences between your first post and your schematics so I will go on with the schematics.
Firstly, you should consider having a higher input capacitance value (we recommend 10uF in the DS). Additionally, the first output cap should be placed outside the feedback loop.
Second of all, the resistor on the EN pin is not needed (may I know what are you using it for and depending on what do you have 1K or 10k value?)

Best regards,
Omar

0 Omar Hegazi over 6 years ago in reply to Omar Hegazi

TI__Intellectual 1780 points

Hi Wolfgang,

Were you able to identify and solve the issue you were facing?

Best regards,
Omar

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TPS82130: TPS82130 EN defect