TMP235: Output voltage issue

Vsevolod Elantsev4

Part Number: TMP235

Hi team,

My customer have issue with TMP235A2DCKR. The customer have schematis according to the datasheet. Rfilter is 10 Ohm, Cfilter is 680 pF, Supply voltage is 3.3V.

Device marking - 19L - same as in datasheet.

The output voltage rising up and then drops down. Please see the scopes:

over 5 years ago

0 Amit Ashara over 5 years ago

TI__Guru**** 244380 points

Hello Vsevolod

The description is rather vague here. What is the operating temperature and what is the customer trying to do (i.e. expected behavior) and what the waveform is showing?

0 Vsevolod Elantsev4 over 5 years ago in reply to Amit Ashara

TI__Intellectual 2425 points

Hi Amit,

Thank you for the reply.

Tests are performed on room temperature. The customer trying just to make the device work. Waveform is showing the output voltage of the device.

The customer expect to get DC voltage corresponding to the room temperature.

0 Amit Ashara over 5 years ago in reply to Vsevolod Elantsev4

TI__Guru**** 244380 points

Hello Vsevolod

Can the customer please do the following few things

1. Provide a waveform with both supply voltage and the output voltage?
2. Please provide the confirmation that a decoupling capacitor is provided on the supply pin close to the device.
3. Is the behavior on every device, that the customer is testing with? Did the customer try a A-B-A replacement to check if the issue is with the device or the board?
4. What is the total load as seen by the device?

0 Amit Ashara over 5 years ago

TI__Guru**** 244380 points

Hello Vsevolod

Is there any update regarding the issue?

0 Vsevolod Elantsev4 over 5 years ago in reply to Amit Ashara

TI__Intellectual 2425 points

Hi Amit,

Yes the customer found issue in the scematic.

The reason was in the sensor's load circuit.

0 Amit Ashara over 5 years ago in reply to Vsevolod Elantsev4

TI__Guru**** 244380 points

Hello Vsevolod

Can you please share details on the sensor load circuit, that was causing the issue, so that we can reproduce the issue and better understand the system implementation for the TMP235?

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TMP235: Output voltage issue