LMZ14201H: LMZ14201H Not working !!! What could be the reason ?

vivek kavalalath

Part Number: LMZ14201H

Tool/software:

Hi,

I have did a design with LMZ14201H , Input from 24V and output is 12V/ Max <1A current.. But without any load, if I power on, then output voltage is 16V in DMM in scope its actually fluctuating. When I check the feedback its 2V in DMM and Enable is 1.6V , I dont know what is happening, I have replaced IC,replaced the SS cap, nothing is working.

, I removed the input cap then also i checked ;no change,

What could be the problem here?

8 months ago

0 ARPITA NATH 8 months ago

TI__Expert 6882 points

Hi Vivek,

Please share waveforms of Vout, SW node, FB node for better understanding and debug. What input voltage are you applying? With 24V inputs, EN should be 4.8V. Can you please probe VIN pin as well to check if there is any drop? Also, try connecting a dummy load (10mA or so) also and share the scope waveforms.

Regards

Arpita

0 vivek kavalalath 8 months ago in reply to ARPITA NATH

Prodigy 20 points

Hello Arpita,

I have connected the load and tried, but little drop in the voltage. Input doesn't have any change at that time. I have replaced three IC's and tried still the same. PCB also verified. the part number I have purchased part number is LMZ14201HTZ/NOPB.

0 ARPITA NATH 8 months ago in reply to vivek kavalalath

TI__Expert 6882 points

Hello Vivek,

Could you please probe and share the above-mentioned waveforms for better understanding and debug? Also, please measure input voltage at the Vin pin of IC and share.

LMZ14201HTZ/NOPB should be fine with 12V output.

Regards,

Arpita

0 vivek kavalalath 8 months ago in reply to ARPITA NATH

Prodigy 20 points

Could you pl let me know how does the UVLO working in this IC ! Can I use enable voltage as UVLO?

0 ARPITA NATH 8 months ago in reply to vivek kavalalath

TI__Expert 6882 points

Hi Vivek,

Please follow "8.2.2.1.1 Enable Divider, RENT and RENB Selection" of the Datasheet. RENT and RENB implements the programmable UVLO.

Regards

Arpita

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LMZ14201H: LMZ14201H Not working !!! What could be the reason ?