CCS/BOOSTXL-BUCKCONV: Output voltage ERROR

Pavan Kumar Kanikicherla

Part Number: BOOSTXL-BUCKCONV

Tool/software: Code Composer Studio

Hello,

I am following this link

http://link.brightcove.com/services/player/bcpid3917207363001?bckey=AQ~~,AAADeK19QZE~,BDUED4gHjR8HLl1b_DFhPB4WG3B025_s&bctid=4107345616001

After Running the programe and turn on 9V

output voltage will ramp upto 2V check the screenshot

But for me it is ramping to 6V ( check next image)

why?

what are the changes i have to do ?

I din't change any default values, i just followed the video link which i provided up

over 4 years ago

0 Han Zhang6 over 4 years ago

TI__Expert 5985 points

Are you using the same launchpad and boosterpack combination as the example code? Have you connected any load to the Buck converter?

0 Pavan Kumar Kanikicherla over 4 years ago in reply to Han Zhang6

Prodigy 140 points

YES Han Zhang6,

I am using same combination

load ?

i just following the procedure .....same combination as that video.

0 Han Zhang6 over 4 years ago in reply to Pavan Kumar Kanikicherla

TI__Expert 5985 points

Form the screenshot you provided, the duty cycle output from compensator is already down to 0, which means low side switch should always be on and high side switch off. The voltage should now be 6V if there is no hardware fault. Please try to follow the steps to debug your hardware:

Probe the PWN-HI and PWN-LO to verify the duty cycle is output as expected
Probe the gate driver output H-Drv and L-Drv to make sure gate driver is working properly
Probe the Li pin near N1 to see the sw output

With these steps, you should be able to locate the fault on your board.

0 Han Zhang6 over 4 years ago in reply to Han Zhang6

TI__Expert 5985 points

Do you have any update on this topic? I will close this thread for now and please feel free to post follow up question. Thanks.

0 Pavan Kumar Kanikicherla over 4 years ago in reply to Han Zhang6

Prodigy 140 points

Hello,

I probe at both H_drv & L_drv. Please check the waveforms.

H_drv

L_drv

0 Han Zhang6 over 4 years ago in reply to Pavan Kumar Kanikicherla

TI__Expert 5985 points

Pavan,

It clearly shows that the gate driver is not working properly. Please working on fixing the hardware (maybe replacing the driver chip). Thansk.

Han

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CCS/BOOSTXL-BUCKCONV: Output voltage ERROR