ZHCSDC8A December 2014 – November 2017
PRODUCTION DATA.
The bq24193 has 1.5-MHz switching frequency to allow the use of small inductor and capacitor values. The Inductor saturation current should be higher than the charging current (ICHG) plus half the ripple current (IRIPPLE):
The inductor ripple current depends on input voltage (VBUS), duty cycle (D = VBAT/VVBUS), switching frequency (fs) and inductance (L):
The maximum inductor ripple current happens with D = 0.5 or close to 0.5. Usually inductor ripple is designed in the range of (20 to 40%) maximum charging current as a trade-off between inductor size and efficiency for a practical design. Typical inductor value is 2.2 µH.