Here is their answer and my question:
May I know whether or not I can do away without the 10 uF set/reset coil's capacitor ?
The datasheet mentions something about a charge pump: In the device status register, bit #3:
"Pump On Indicates the charge pump status."
Does the 10 uF capacitor on the CAP pin have anything to do with this charge pump ? If yes, what voltage swings are expected on the CAP pin ?
I do not intend to ever use the set/reset coil. Datasheet says:
"The SET/RESET function can be performed for each measurement, periodically, or when the temperature changes by a predetermined amount as the specific application requires. In addition, the SET/RESET function clears the sensors of any residual magnetic polarization resulting from exposure to strong external magnets."
I have no need for these functions above. So, will the MMC5883MA run fine without that 10 uF cap ?
10uF is a must for MMC5883MA, and no need to use the charge pump.
Please let us konw your application and company, then we can provide better support. Thanks.
No further answers from them. I have tried taking out the 10 uf cap for testing; it seemed to work fine without it. Since they say I need it I shall leave it there. But I still wonder why it is needed...