• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 29 subscribers
  • Views 488 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.

DRV8323R: A bare bones preliminary test of the DRV8323R

Joshua Mitchell
Prodigy 60 points
Part Number: DRV8323R


Hi there,

I built a prototype motor driver using the DRV8323RS. However, I had to hand solder this package which isn't easy. So i decided to solder it first and run a preliminary test on the chip before I start soldering all the other expensive bits on. 

The test hypothesis:

1) Solder only the DRV8323RS onto the board. ( no caps, no resistors, JUST the DRV)

2) Apply ~25V at the DC bus input so that VM and VIN are energised, 

3) no current should be drawn, chip should be dormant. 

4) Apply 3.3V to the ENABLE Pin, and then measure DVDD, which should be 3.3V.

5) measure nFAULT which may or may not be low. 

So I did all this and it went swimmingly up til (4).  Once I apply 3.3V to ENABLE, the chip draws about 50 mA from the 25V supply and heats up. DVDD measures ~2V. Haven't let this run too long for fear of starting a small DRV shaped fire. 

Doesn't sound good. Which leads me to my question. Could this be because the VCP, CPH/CPL capacitors are not soldered? Or is there something more fundamentally wrong. 

I thought I broke the first chip I soldered on, so I tried another one but same scenario. 

Thanks for the help! 

  • 0
    TI__Expert 8985 points

    Hi Joshua,

    Can you please place the highlighted capacitors on the board and get back to me? Especially the DVDD capacitor.

  • 0 in reply to Hector Hernandez Luque
    Prodigy 60 points

    Hi Hector, 

    I can confirm that the DRV functions correctly when those caps are soldered.  Draws about 10 mA and DVDD is set to 3.3V when ENABLE is 3.3V. 

    If any of those caps had to become damaged during operation or fail from old age, the chip would heat up and probably break. Perhaps a good thing to note in the datasheet? 

    Thanks for the help

    P.S do you have any scripts for the SPI interface. I know the datasheet details the commands and timing etc.  extensively.

    I am just hoping to save some time by using someone else script for the SPI interface rather than writing it from scratch.. 

    Regards

    Joshua