About VCOIN register setting for MMPF0100

[george]

Dear all,

I want to adjust the voltage for charging from PMIC (MMPF0100F0AEP) to Li-Battery.

Though VCOIN [2:0] (ADDR 0x1A) was changed to 100 from 000, It seems that the voltage to LICELL pin does not change.

If the register value is read, it is changed correctly.

Is anything else needed?

Best Regards,

George

[igorpadykov · Accepted solution]

Hi George

additionaly one needs to set bit COINCHEN=1

and check that VIN > UVDET (3.1v) sect.6.4.7.1Coin Cell Battery Backup

MMPF0100

Also charger behaves as current-limited voltage source, resulting in the CC/CV

taper characteristic. If you cannected licell with small internal resistance,

it is difficult to see change. One can try to imitate licell connecting 50kOhm resistance

(50K*60uA=3.0V) and check voltage on it.

Best regards

igor

[george]

Dear Igor,

Thank you for explanation carefully.

BR,

Geroge