Tool/software: Code Composer Studio
Hi everyone. I am testing the charger circuit for a supercapacitor connected on AUX2VCC. I was suspecting that my configuration was not working as expected and today I noticed that depending were I set my AUX2CHTL register on the setup code the charger circuit the FW generated could produce a workable charger or not-workable charging behavior.
Here is my setup:
* 3.3 on DVCC;
* 2.5 external suply between GND and AUX2VCC (Emulating an half-life supercapacitor) with a serie precision multimeter;
* Configuration to charge to VCC and use 5 kohm charger resistor;
* On boot procedure, I added an blink routine as boot OK procedure.
Here is the code part and the picture that produces a not workable charger:
This configuration produces an wrong current from AUX2VCC varing between 381 and 63 nA as presented on the figure bellow. I wasn't expecting a positive current and wrong values from 5kohm charger resistor.
NOW, changing just the line where I set the AUX2CHCTL on the same code segment, the charger circuit start working fine. Look for the code changed:
This cronological sets produces a current on AUX2VCC of:
Wich is the expected current from 3.3V over an emulated 2.5V supercapacitor through 5kohm resistor. ((3.3-2.5)/5e3) = 160uA.
My question is? Why is it happing? I did not change anything on my setup. Can I expect other sets problem (unworkable code) along my program setup?
Thanks.
