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UCD8220: UCD8220PWP Failure on power on

Silvano Cerini
Prodigy 10 points
Part Number: UCD8220

Tool/software:

Good morning,
I need help with this problem.
I'm trying to use the UCD8220PWP PWM controller.
I made a circuit that I'm absolutely sure of with the UCD8220PWP component correctly powered, that is, VDD = 5V and PVDD = 15 VDC.
All the remaining input pins are connected to ground (intentionally).
During power-up (power supply at 15 and 5V), the component draws a high current and fails after a few seconds.
The power supplies have their own 4.7 uF bypass capacitors in parallel, each 100nF.
Why is this happening? Unfortunately, I've already burned five of them.
Can you help me?
I know the hanging pins shouldn't be there, but I want to test them under these extreme conditions and the component mustn't break!
What precautions should I take?


Thank you so much for your support.

  • 0
    TI__Guru 73805 points

    Hi,

    When you connect all input pins to GND, it is possible each pin has different leakage current and internal impedance difference so the voltage on each pin not exactly 0. There could be combinations to demand high startup current. Your connections are not tested and not a known result so it is not good to test the circuit this way.

    I suggest you to connect pins normally to make test.