BQ24030-Q1 Datasheet, PDF (17/34 Pages) Texas Instruments – SINGLE-CHIP CHARGE AND SYSTEM POWER-PATH MANAGEMENT IC

bq24030-Q1
bq24031-Q1
www.ti.com.................................................................................................................................................... SLUS793B – APRIL 2008 – REVISED OCTOBER 2009
Figure 9 illustrates that when AC is applied, power transfers from USB to AC [PSEL = H, channel 1 (CH1)
VAC = 5.4 V, channel 2 (CH2) V_(USB) = 5 V channel 3 (CH3) V_OUT, output current I_OUT = 0.25 A, channel 4 (CH4)
V_BAT = 3.5 V, and I_(PGM-CHG) = 1 A]. The charger is set for AC priority but is running off USB until AC is applied.
When AC is applied (first division) and the USB FET opens (second division), the AC FET closes (third division)
and the output recovers from the DPPM threshold (eighth division).
Break Before Make
V_AC
V_USB
V_OUT
V_BAT
V_OUT Returns to Regulation
Charging Current Returns to I_pgm
DPPM Mode
Figure 9. Apply AC – Power Transfer From USB to AC
Figure 10 illustrates when USB is removed, power transfers from USB to AC [PSEL = L, channel 1 (CH1)
VAC = 5.4 V, channel 2 (CH2) V_(USB) = 5 V, channel 3 (CH3) V_OUT, output current I_OUT = 0.25 A, channel 4 (CH4)
V_BAT = 3.5 V, and I_(PGM-CHG) = 1 A]. The USB source is removed (second division) and the output drops to the
battery voltage (declares USB bad, fourth division) and switches to AC (in USB mode) and recovers similar to the
figure that is switching to USB power. This power transfer occurs with PSEL low, which means that the AC input
is regulated as if it were a USB.
AC is Applied (USB Mode)
AC Hits USB (ISET2) limit
DPPM Mode
USB Declared not Present
V_AC
V_OUT
V_USB
V_BAT
Figure 10. Remove USB – Power Transfer From USB to AC
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