BQ24160 Datasheet, PDF (16/44 Pages) Texas Instruments – 2.5A, Dual-Input, Single Cell Switchmode Li-Ion Battery Charger with Power Path

bq24160, bq24161
bq24163, bq24168
SLUSAO0A – NOVEMBER 2011 – REVISED MARCH 2012
CHARGE MODE OPERATION
www.ti.com
Charge Profile
The internal battery MOSFET is used to charge the battery. When the battery is above the MINSYS votlage, the
the internal FET is on to maximize efficiency and the PWM converter regulates the charge current into the
battery. When battery is less than MINSYS, the SYS is regulated to V_SYS(REG) and battery is charged using the
battery FET to regulate the charge current. There are 5 loops that influence the charge current:
• Constant current loop (CC)
• Constant voltage loop (CV)
• Thermal-regulation loop
• Minimum system-voltage loop (MINSYS)
• Input-voltage dynamic power-management loop (V_IN-DPM)
During the charging process, all five loops are enabled and the one that is dominant takes control. The bq2416x
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 for a missing or deeply discharged battery. Figure 22 shows a typical charge profile including the minimum
system output voltage feature.
Regulation
voltage
Precharge
Phase
Current Regulation
Phase
VSYS
System Voltage
Voltage Regulation
Phase
Charge Current
Regulation
Threshold
V_BATSHORT
Battery
Voltage
Charge Current
Termination
Current
Threshold
I_BATSHORT
50mA Precharge to
Close Pack Protector
Linear Charge
to Maintain
Minimum
System
Voltage
Battery FET is ON
Battery
FET
is OFF
Figure 22. Typical bq2416x Charging Profile
PWM Controller in Charge Mode
The bq2416x provides an integrated, fixed-frequency 1.5MHz voltage-mode controller to power the system and
supply the charge current. The voltage loop is internally compensated and provides enough phase margin for
stable operation, allowing the use of small ceramic capacitors with very low ESR.
The input scheme for the bq2416x prevents battery discharge when the supply voltages are lower than VBAT
and also isolates the two inputs from each other. The high-side N-MOSFET (Q1/Q2) switches to control the
power delivered to the output. The DRV LDO provides a supply for the gate drive for the low side MOSFET,
while a bootstrap circuit (BST) with an external bootstrap capacitor is used to boost up the gate drive voltage for
Q1 and Q2.
16
Submit Documentation Feedback
Copyright © 2011–2012, Texas Instruments Incorporated
Product Folder Link(s): bq24160 bq24161 bq24163 bq24168