• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 63 subscribers
  • Views 435 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.

PTH04040 - OUTPUT NOT GENERATED- VOADJ ISSUE

Sakthi Annamalai
Intellectual 610 points

Hi

 

   We are using PTH04040 power module in one of our board for generating the 1V output from 5V input. We manufactured 10 boards with the power module. Out of 10 boards,in 5 boards the power module is not generating the output at all times.

In 5 boards,the module is generating the 1V output as desired after powering on the board . Measured voltage is 4.2V at INH (pin no: 7 ) and also 0.79V at VO-ADJ,Mar-Up and Mar-Down(Pin no: 17,19,20) in working module.

In Non working module, . measured the voltages as follows 4.2V at INH (pin no: 7 ) , 0.79V at Mar-Up( pin no:19) and 0V at VO-Adj ,Mar-Down(Pin no: 17,20) . Some times this non working module is generating the output if do powering on and off the board many times.

We have connected 36.5K with 0ohm series resistor between pin no:17 and ground to generate 1V output. Even ,I have removed the two series resistors and mounted 36.5K directly between pin no:17 & 18.

As per datasheet specification, the Voltage VO-ADJ should be in between 0.8V and 2.5V.

The input voltage 5V is fine at all times. Our current requirement is 35A.

Please find attached the Schematics

Need immediate suggestions to sort out the issue.

 

Thanks

Sakthi.APOWER-POLA-Schematics.pdf

  • 0
    TI__Mastermind 38230 points

    Sakthi:

    I reviewed the schematic  and pin  voltage details. 

    Can you contact  me off line at tguerin@ti.com  with additional data and top side picture of the PTH04040WAx.

    1. What is the total output capacitance? In this application, there are only polarized 2x 330uF 10V, ESR 15mΩ C749 and C1021, are there any additional polarized capacitors on Vout 1V0 bus ?If so , how much capacitance ?

    2.  Output ceramic capacitance total on 1V0 bus? What is the total amount of ceramic capacitance  located on 1V0 bus?

    3. What is the track pin voltage, pin 18, and UVLO ,pin 8, voltages?

    Regards

    Tom