Mehmet Fide

LC60: Internal Temperature Sensor(AD26 value decreases when temperature increases)

Discussion created by Mehmet Fide on Oct 25, 2007
Latest reply on May 12, 2010 by bigmac
I want to measure working temprature by using internal temperature sensor of LC60 to compensate deviation at external real-time crystal(32.768kHz) over temperature. Accuracy is not so important, +-5 C degree is enough for me.
The datasheet indicates an equation at page 268 ( Temperature Sensor section):
TempC = (Vtemp – 0.7013) ÷ (0.0017)

I recalculated 0.0017 value and found my calibrated divider instead of this value (only at 25 C degree).
The problem is here:
Measured Temperature is 25C at 25Cdegree room. OK
Measured Temperature is 15C at 35Cdegree room. ?
Measured Temperature is 35C at 18Cdegree room. ?

I'm using AD26 channel voltage as Vtemp.  Am I missing something?

Message Edited by BasePointer on 2007-10-25 03:58 PM