Other Parts Discussed in Thread: CONTROLSUITE, REF3030
Hi,
I have a piece of code that reads out the internal temperature sensor. It is largely based on the example provided in ControlSUITE.
The main difference is that the sensor reading (from ADC-A channel 13) is stored in SOC13, which is software triggered every 10ms.
Running the code on a LAUNCHXL-F28377S eval board works just fine, sensor readings make perfect sense.
However, the same code produces a much to high reading (roughly 60% off) on the target HW design (which was based on a previous version of the LAUNCHXL).
The only hardware difference that I can spot so far, is that the LAUNCHXL uses a unity gain OP-AMP after the voltage reference source (REF3030)
to feed the ADC reference voltage while the target design directly connects the REF3030 to VREFHI and uses a buffer cap.
So the reference voltages are the same, the code is the same.
On the target device the ADCs are connected to actual peripherals, could this make a difference for the internal temperature sensor reading?
What could I possibly be missing?
Are there some timing constraints on the sampling of the temperature sensor?
Is the unity gain OP-AMP really optional as the reference manual says, or is it a must-have under some circumstances?
Kind Regards,
Andreas Fellnhofer
