bq24030, bq24031, bq24032,
bq24032A, bq24035, bq24038, bq24039
www.ti.com
SLUS618C–AUGUST 2004–REVISED JUNE 2005
Figure 12 illustrates when a battery is inserted for power up; channel 1 (CH1) VAC = 0 V; channel 2 (CH2) VUSB
= 0 V; channel 3 (CH3) VOUT; output current, IOUT = 0.25 A for VOUT > 2 V; channel 4 (CH4) VBAT = 3.5 V; C(DPPM)
= 0 pF. When there are no power sources and the battery is inserted, the output tracks the battery voltage if
there is no load (<10 mA of load) on the output, as shown. If a load is present that keeps the output more than
200 mV below the battery, a short-circuit condition is declared. At this time, the load has to be removed to
recover. A capacitor can be placed on the DPPM pin to delay implementing the short-circuit mode and get
unrestricted (not limited) current.
V
BAT
V
OUT
Figure 12. Insert Battery – Power-Up Output via BAT
Figure 13 illustrates USB bootup and power-up via USB; channel 1 (CH1) V(USH) = 0 to 5 V; channel 2 (CH2)
USB input current (0.2 A/div); PSEL = Low; CE = High; ISET2 = High; VBAT = 3.85 V; V(DPPM) = 3.0 V (V(DPPM)
×
1.15 < VBAT, otherwise DPPM mode increases time duration). When a USB source is applied (if AC is not
present), the CE pin and ISET2 pin are ignored during the boot-up time and a maximum input current of 100 mA
is made available to the OUT or BAT pins. After the boot-up time, the IC implements the CE and ISET2 pins as
programmed.
20
TI [ TEXAS INSTRUMENTS ]
