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AM57x short on 3 power supply rails

Other Parts Discussed in Thread: TPS659039-Q1, TPS659037, TPS65916, X5777BXGABC, X5777AXGABC

Hi,

 I have used TPS659039 PMIC and AM57XX processor for one of our project.

At present facing low impedance issue (0.5 ohm) for three voltage rails.

 I have provided below snapshot for usage of PMIC in this application.

 

Faced same issue earlier, but rectified the problem by un-mounting PMIC and processor. Then assembled new PMIC and processor.

 Again facing similar issue where suspecting problem at PMIC and processor by usage of toneohm meter.

 Common observations during this failure at both these instances are as follows:

  • Unit in which this card is assembled has the feature to use two batteries which are controlled by usage of DPDT switch
  • When the unit is powered-on (with usage of battery) power good LEDs on the board are not turned-on. After further debugging identified short at three voltage rails
  • SMPS7 -->  VCC_Core --> used between PMIC and processor
  • SMPS9 --> VCC_1V8 --> used between PMIC and processor
  • VCC_3V3 --> Connected to processor only. GPIOs of PMIC will control the voltage of this section

Not able to identify the root cause for this. Please check and let us know your observations on this.

Regards,

Mani