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TMP423: Filter tuning

Part Number: TMP423

Hi Team,

Now we use TMP423. CH1 and CH3 are normal, but CH2 monitor Temp would abnormal drifting.

We can remove C3053 or change R6761/6762 to 50ohm can get the normal behavior.

We know data sheet suggest 100pF+50ohm on each input. Does this mean Q299 locate in a noisy place?

Could you give us the filter tuning guide for TMP423? Customer request to know how to tune the RC value.


  • Hi Daniel,

    Did you test with 50ohm? I ask because the schematic shows 0ohm.

    For best performance, the DX traces should be shielded and routed away from noise sources. To identify noise, it would be helpful to compare oscilloscope images of DX1, DX2 and DX3. Additionally, the R+C filtering may be more effective if it is located close to the Q device.

    Please see the following app note for information on optimizing remote junction temperature sensors.