• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 63 subscribers
  • Views 277 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.

LV14340: Output getting unstable

Mohit Singh1
Prodigy 215 points

Part Number: LV14340

Tool/software:

Hi,

I am using this circuit to convert 12VDC to 5VDC. Due to some mistake with the footprint we were unable to mount the D13 diode (Part : SK54-3G) on the PCB directly, so for the prototype we soldered one end of the diode directly to the capacitor and a 1 inch jumper wire from other end to a ground point.

I have verified that the connection is secure and not touching any other components.

The issue is sometimes the output voltage just drops after a few seconds, it keeps on fluctuating. Other times, it works fine with 5V output and the rest of the board working fine.

I want to ask if the wire length added can cause such an issue, I just want to make sure there are no other issues before I go for the redesign.

Although it is not clear from here but I can confirm that C32, D13, L4 and U4.8 are connected.

  • 0
    TI__Mastermind 22290 points

    Hello,

    Overall, the schematic looks OK.

    Yes, layout issues such as the one you describe in the post can cause unexpected behavior. The ground loops are very important for a buck converter, especially with the high di/dt loops such as the SW node. The long ground loop for the diode could be causing some instability in your design.

    Please refer to the layout section of the datasheet for recommendations on optimal layout for this device. 

    Best regards,

    Ridge