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TPS65130: No positive and negative output

Shaofeng Luo
Intellectual 1650 points
Part Number: TPS65130

HI team

We use TPS65130 to generate ±15V from a 5V supply, but we found that TPS65130 can output correctly with no load,but can't output with even 10mA load.

We check the SW point of positive and negative as the figure below:

Positive: most of time is High, and only low for 250ns.

Negative: Yellow is SW point voltage, only several pulse here just like entering hiccup mode, the Pink is the inductor current, it's only 100mA here and seems will not lead to OCP.

The schematic is as below:

We tried to add the feed-forward cap on the feedback network but it doesn't work, BTW, the VREF of the IC is about 1.251, which already exceeds the max value 1.225.

We may need your insight to find the root cause, thanks!

  • 0
    TI__Mastermind 18550 points

    Hello,

    We have few other support tasks ahead of this one so please allow another couple of days for us to review and feedback. We will get back to you by Monday US time.

    Kind Regards,

    Liaqat

  • 0 in reply to Liaqat Khan
    TI__Mastermind 18550 points

    Thank you for your patience. I reviewed the schematics and your problem description in detail and schematically, the design looks correct so the only thing I can think of is some board assembly issue. Is this behavior occurring on one board or more than one board have been assembled and they all behave this way? Also, can you please disable the inverting converter by tying ENN to GND and see if the boost converter can work at loaded conditions? Similarly, can you please disable boost converter by tying ENP to GND and see if the inverting converter can work at loaded condition by itself?

    Kind Regards,

    Liaqat