BQ25730: about CHG_OK high

Tool/software:

Dear TI expert,

Currently, i am designing a new project, use BQ25730+BQ40Z80, the battery is 5s2p，the BQ25730 input source is 20V5A, the battery voltage from 13.75V to 21V. In page 85, 10.2.2.3 Inductor Selection

in buck mode, D close 0.5, DBUCK = VOUT/VIN; Vout=0.5*Vin=10V, so i select Vout 13.75V calculate IRIPPLE_BUCK = VIN × DBUCK× (1-DBUCK) / (fS × L)

in boost mode, DBOOST = 1 – (VIN/VBAT); so BVAT is 21V, the DBBOST=1-10/21=0.048, so i slected VBAT is 21V;RIPPLE_BOOST = (VIN × DBOOST) / (fS × L), is right?

another question, when CHG_OK is HIGH, the voltage is 3.3V? i want this is output voltage is 3.3V.