BQ24266_15 Datasheet, PDF (20/41 Pages) Texas Instruments – bq24266 3A, 30V Standalone Single-Input, Single-Cell Switchmode Li-Ion Battery Charger

bq24266
SLUSBY5F – JUNE 2014 – REVISED AUGUST 2015
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Device Functional Modes (continued)
into the battery. The current from the supply is shared between charging the battery and powering the system
load at SYS. The dynamic power path management (DPPM) circuitry of the bq24266 monitors the current limits
continuously and if the SYS voltage falls to the V_MINSYS threshold, it adjusts charge current to maintain the
minimum system voltage and supply the load on SYS. If the charge current is reduced to zero and the load
increases further, the bq24266 enters battery supplement mode. During supplement mode, the battery FET is
turned on and V_BAT = V_SYS while the battery supplements the system load.
2000mA
1800mA
I_SYS
800mA
0mA
1500mA
I_{IN ~850mA}
0mA
1A
I_BAT
0mA
–200mA
V_SYS
3.6V
3.5V
~3.1V
DPPM loop active
Supplement
Mode
Figure 11. Example DPPM Response (V_Supply = 5V, V_BAT = 3.1V, 1.5A Input Current Limit)
7.4.9 Battery Discharge FET (BGATE)
The bq24266 contains a MOSFET driver to drive an external discharge FET between the battery and the system
output. This external FET provides a low impedance path for supplying the system from the battery. Connect
BGATE to the gate of the external discharge P-channel MOSFET. BGATE is on (low) under the following
conditions:
1. No input supply connected.
2. IUSB1, IUSB2, IUSB3 pins = high
7.4.10 IUSB1, IUSB2, and IUSB3 Input
The bq24266 has three inputs that configure the input current limit and VINDPM thresholds. These input are also
used to enable the USB OTG Boost function. The bq24266 incorporates all of the necessary input current limits
to support USB2.0 and USB3.0 standards, as well as 1.5A to support wall adapters. Driving IUSB1, IUSB2, and
IUSB3 all high places the bq24266 in Hi-Z mode where the buck converter is shutdown regardless if an input is
connected to IN. Table 1 shows the configuration for IUSB1, IUSB2, and IUSB3.
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