• State
  • Locked Locked
  • Replies 1 reply
  • Subscribers 63 subscribers
  • Views 686 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TPS79333-EP: Vout is not good, Vout=0

user5840537
Intellectual 295 points
Part Number: TPS79333-EP

Recently, there are about 8pcs control boards with abnormal Vout output. We tested all the components of the control board, and finally located TPS79333DBVR with abnormal output, Vout=0. After doing a crossover test, it is normal to replace it with a new TPS79333DBVR circuit. Can you help us find out where there are design problems with our SCH and PCB? Or what do we need to pay attention to in design

Test data：

Vin=5V。

Vout= 0V,

VNR= 1V，

impedance TPS79333-OK TPS79333-NG
Vin->GND ∞ 1.4MΩ
GND->Vin (1.2-1.6)MΩ 1.2MΩ
Vout-GND 113.1KΩ 118.8kΩ
GND->Vout 113.1KΩ 118.8kΩ

  • 0
    TI__Mastermind 37065 points

    Hello,

    Nothing stands out as being incorrect with your schematic or layout.  For the next steps, I would try measuring the different signals with an oscilloscope.  I would measure Vin and Vout.  I would also review if there were any fast transients in the system which could result in inductive ringing on Vin or Vout, and result in transient voltage below GND.  If those conditions exist then the device may have been damaged from exceeding abs max values.

    Thanks,

    - Stephen