Part Number: MSP430FR5989
I have an aplication that uses the ESI from the MSP430FR5989 for rpm counter using 3 LCs. The sensing mechanism is fine and stable, but i had to write an algorithm for constant recalibration.
I would like to remove this "background calibration". The first thing i did was to use the comparator offset cancellation procedure (37.2.1.7 from family guide) and make sure there is no drift related to temperature in the SMCLK that is configured to be used by the ESI. This is working because i didnt notice any drift in each LC oscillation when fast changing the temperature in the board.
But the temperature is still heavily influencing the ESI. The 0.2 uV/C that is expected in the comparator offset seems to be much higher, even higher than when not using the autozeroing procedure....
Is any other parameter that could be affected by temperature? I discarded the LC and the SMCLK oscillator, i even put a TXCO directly in HFX to make sure there is no drift in the clock used by the ESI.
Thanks !
