Other Parts Discussed in Thread: MSP-EXP430FR2433, MSP430WARE
Hi community member,
<Phenomenon occurrence>
Since I want to set DCO frequencyto 4.9152MHz, DCORSEL is set to 2.
But there are chips that DCO in MSP430FR2433 oscillates unstable when it is reset in cold environment.
Rently, chips that cause this symptom have appeared again.
3 out of 140 chips were confirmed.
There are variations each chips in the temperature at which the phenomenon occurs.
Device A: Around -30 degrees
Device B: Around -35 degrees
Device C: Around -38 degrees
When each chip is lowered to the respective temperature, the phenomenon occurance rate is 100%.
The phenomenon has also occurred on LaunchPad(MSP-EXP430FR2433).
The sample software that confirmed this phenomenon is below.
Based on "cs_ex1_DCO1MHzSWTrim.c" of MSP430Ware, it is changed so that DCO = 4.9152MHz.
Even if DCOFTRIM looped from 0 to 7 in the "privateCSComputeDCOFTrim()", the DCO tap does not become an appropriate value, and the DCO does not oscillate stably.
<Datasheet>
Looking at the datasheet (figure 5-5), we think that DCORSEL = 2 is suitable to set DCO = 4.9152MHz.
Furthermore, the temperature range in figure 5-5 is written as TA = -40 °C to 85 °C.
The previous comment says “the DCO is out of range under the given temperature.”.
But I think that it is correct to set DCORSEL = 2 to oscillate DCO = 4.9152MHz in the whole temperature range.
Do you think this is a chip defect?
Please let me know the views of TI members?
If this problem isn't solved, our work cannot progressing next step on project.7853.cs_ex1_DCO1MHzSWTrim_Modify.zip
Best regards.
Cruijff
