TLV9054: 800MV drift waveform.

Robin Zhou

Part Number: TLV9054
Other Parts Discussed in Thread: TLV9034

Dear TI Experts,

There is a question about TLV9054：

The chip is loaded with no load, single power supply plus chip peripheral device. Using oscillometric test method, 200MV AC block test chip 14 pin output waveform is shown as below, the output waveform has 800MV drift waveform.

Normally, without an access sensor, the output waveform should be a 1.5V reference.
Test point: 1 2 3 output waveform voltage 1.5V (under no load)

Looking forward to your reply~

Thanks,
Robin

over 5 years ago

0 kai klaas69 over 5 years ago

Guru 140200 points

Hi Robin,

can you show a schematic?

Kai

0 Robin Zhou over 5 years ago in reply to kai klaas69

Intellectual 625 points

Hi, Kai,

Please refer as below, SGM8634 IS P2P with TLV9034

0 Bala Ravi over 5 years ago in reply to Robin Zhou

TI__Expert 6625 points

Hi Robin,

What are you trying to accomplish with this circuit? Also please note that the specs for TLV9054 and SGM8634 are different.

Are you noticing a 800mV drift at "ADC1 PC5"? Are you trying to build a voltage follower circuit?

Best Regards,

Bala Ravi

0 Robin Zhou over 5 years ago in reply to Bala Ravi

Intellectual 625 points

Hi Bala,

Is it meaning that I should test again at "ADC1 PC5"? Could you tell me how to build a voltage follower circuit?

I select TLV9054 just refer to the TI's reference tool.

Thanks,
Robin

0 Ron Michallick over 5 years ago in reply to Robin Zhou

TI__Guru*** 147906 points

Hello Robin,

Try checking the output signal with C28 removed (no input signal) .

I noticed that the P2 connector generates the 1.5V supply but there is no ground connection at P2 connector. What is connected to P2 pin 4 and how long is the cable? Is the 1.5V supply very clean (try AC coupling).

Do multiple samples of op amp have the same output?

0 Robin Zhou over 5 years ago in reply to Ron Michallick

Intellectual 625 points

Hi, Ronald,

Today，I tested it again. The ripple mainly occurs when the 4G module communication connection, and the wave is stable and clear before and after the connection.

I guess the ripple is because of the power supply.
Any suggestions for this?

(The ripple of TLV9054 VS SGM8634)

Thanks,
Robin

0 Bala Ravi over 5 years ago in reply to Robin Zhou

TI__Expert 6625 points

Hi Robin,

To avoid electrical interference try to use proper shielded cables. You can try your setup in a Faraday cage to block any EMI noise. Also proper ground should be your top priority. A good ground and proper shielded cables should stop electromagnetic interference and keep your measurement signal clean.

Finally, to rule out if your power supply is causing this issue you can try a different power supply and check if you experience the same issue.

Best Regards,

Bala Ravi

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TLV9054: 800MV drift waveform.