TSC1641 temperature sensor use

[aga]

Hi all,

Since the TSC1641 is just a monitor (it doesn’t drive any current), I assume the internal temperature sensor is meant to measure the temperature of something nearby.

In this application, I was thinking the shunt resistor could be placed on the opposite PCB layer to allow the sensor to "read" the shunt resistor's temperature.

Does this assumption make sense? I couldn't find any guidance on this in the datasheet.

Regards,

AGA

[Gael_Miramond · Accepted solution]

Hello Aga, 

Yes the temperature sensor is designed to monitor something close to the circuit.

About the shunt resistor location :

Yes it makes sense, but the image of the shunt temperature will depend on the PCB characteristics (width of metals, FR4, locations of vias).

Metals conduct heat very well, whereas FR4 is much less efficient in conducting heat.

The bottom layers are separated from the top layers by a thick FR4 layer, possibly around 1mm of FR4 without copper. There are only vias in this FR4 layer.

The best location (top or bottom) will depend on the PCB you use. However results should be very close between top and bottom if you place vias in case of bottom location.

If needed, you could make a thermal analysis to help you to define a correction factor to apply to the shunt value.

Best regards,

[aga]

Hi @Gael_Miramond,

many thanks for for answer.

I would eventually suggest to propose (within the datasheet) some use for that internal temperature sensor, otherwise there are not clues about its function.

Kind regards,

AGA

[Gael_Miramond]

Hi Aga, 

Yes you are right, this is something we can add in a next version of the datasheet. 

Best regards,

Gaël