ADS8638: Internal temperature channel is +/- 6.45 Celsius or +/- 43 degrees F? That doesn't seem right?

Hello,

We currently have the ADS8638 designed into one of our products and it works well for reading the analog input data, however, we are having issues when we try to read the internal temperature channel.

The datasheet shows the internal temperature measurement resolution is 5% of full scale reading.  According to the datasheet the full scale analog output code is around 3838.

So if we do the math with the transfer formula provided from the datasheet, we get:

(3838 – 3777.2) / 0.47 = 129 degrees C

5% of 129C is 6.45C which seems high!  That’s 43 degrees F?

Is my math wrong?

Thanks

Terry