UCC21530: Vgs signal low level

Gokhan G.

Part Number: UCC21530

Hi,

I drive one Si MOSFET. There is no power transfer on it and no drain voltage on it.

I attached test circuit diagram and Vgs waveforms. The Vgs of MOSFET isn't close to zero volt. It is 1,28V and its upper level is 13,95V.

Please check as below. Could you please comment on it? Why the low isn't close to zero.

over 1 year ago

0 Don Dapkus over 1 year ago

TI__Guru**** 189399 points

Hi, Gokhan,

It seems like maybe pin 14 is floating according to your schematic? Or, do you have your 15V supply connected +15V to VDDA (pin 16), and the associated ground of the power supply to VSSA (pin 14).

The output should go very close to the voltage applied to VDDA when a high is commanded, and very close to the voltage applied to VSSA when a low is commanded.

Best regards,

Don

0 Gokhan G. over 1 year ago in reply to Don Dapkus

Intellectual 655 points

Hi Don,

I will check it.

When I reduced resistor connected to OUTB, the low level of OUTA is also getting reduced. Could you please comment on it?

+1 Don Dapkus over 1 year ago in reply to Gokhan G.

TI__Guru**** 189399 points

Hi, Gokhan,

Can you post more of your schematic? I don't have enough info to comment based on what you have posted.

Have you reviewed the applications section of the datasheet? I think reading this will help you figure out what is going on here.

Best regards,

Don

0 Gokhan G. over 1 year ago in reply to Don Dapkus

Intellectual 655 points

Dear Don,

I solved the problem. My scope port is damaged. I used another scope and there is no problem.

Thank you.

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UCC21530: Vgs signal low level