BQ24250C_15 Datasheet, PDF (18/46 Pages) Texas Instruments – bq24250C 2A Single Input I2C, Standalone Switch-Mode Li-Ion Battery Charger with Power-Path Management

bq24250C
SLUSBY7 – JULY 2014
www.ti.com
8.4 Device Functional Modes
8.4.1 Charge Profile
The bq24250C provides a switch-mode buck regulator with output power path and a charge controller to provide
optimum performance over the full battery charge cycle. The control loop for the buck regulator has 7 primary
feedback loops that can set the duty cycle:
1. Constant Current (CC)
2. Constant Voltage (CV)
3. Minimum System Voltage (MINSYS)
4. Input Current (I_ILIM)
5. Input Voltage (V_{IN_DPM})
6. Die Temperature
7. Cycle by Cycle Current
The feedback with the minimum duty cycle will be chosen as the active loop. The bq24250C supports a precision
Li-Ion or Li-Polymer charging system for single-cell applications. The Dynamic Power Path Management (DPPM)
feature regulates the system voltage to a minimum of V_MINSYS, so that startup is enabled even with a missing or
deeply discharged battery. This provides a much better overall user experience in mobile applications. The figure
below illustrates a typical charge profile while also demonstrating the minimum system output voltage regulation.
V BATREG
Trickle
Charge
Pre-
charge
Current Regulation
Phase( CC )
ICHG
Voltage Regulation
Phase( CV)
Termination
ICHG
V MINSYS
(3.5 V)
VSYS
VBAT
VLOWV
V BATSHRT
Linear trickle Linear
charge Pre- charge
Linear
fast charger
MINSYS
regulation
BATFET on-- PWM fast charge
BATREG
regulation
BATFET off
I PRECHG
I TERM
I BATSHRT
SYSREG
regulation
Figure 15. Typical Charge Profile
Figure 16 demonstrates a measured charge profile with the bq24250C while charging a 2700mAh Li-Ion battery
at a charge rate of 1A.
18
Submit Documentation Feedback
Product Folder Links: bq24250C
Copyright © 2014, Texas Instruments Incorporated