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LM75A: about the readout temperature accuracy when temp changes fast

Part Number: LM75A

Hi Dear expert,

My customer reported they found LM75A readout temperature accuracy is very big when temperature changes fast.

For eg, when temperature goes up, the actual temperature is 70C, the readout of LM75A is 65C.

When temperature goes down, the actual temperature is 40C, the readout of LM75A is 44C.

There is big latency of LM75A when temperature changes fast.

Below is the schematic.

Is this normal? Do we have ways to improve it?

Thanks,

BEST REGARDS,

Joyce

  • Hello Joyce,

    I have a few questions. How fast is the temperature that is being measured changing? Are they trying to measure air temperature, or the temperature of something on the board?

    There are a few considerations when trying to improve the thermal response time of a sensor, but I don't suspect the schematic to be the cause. Layout is a more important factor here. If there is a lot of thermal mass around the sensor then it is normal for it to have a slow response time because there is a greater amount of heat-energy stored in the system. What's important is to make sure there is a good thermal path between the sensor and what they want to measure.

    Best Regards,
    Brandon Fisher