BQ25606 Datasheet, PDF (18/43 Pages) Texas Instruments – Standalone 3.0-A, Single Cell Battery Charger With 40V Over Voltage Protection Controller

bq25606
SLUSCK6 – MAY 2017
www.ti.com
8.3.2.5 Input Voltage Limit Threshold Setting (VINDPM Threshold)
The device's VINDPM is set at 4.3V. The device supports dynamic VINDPM tracking which tracks the battery
voltage. The device's VINDPM tracks battery voltage with 200mV offset such that when VBAT + 200mV is
greater than 4.3V, the VINDPM value is automatically adjusted to VBAT + 200mV.
8.3.2.6 Converter Power-Up
After the input current limit is set, the converter is enabled and the HSFET and LSFET start switching. If battery
charging is disabled, BATFET turns off. Otherwise, BATFET stays on to charge the battery.
The device provides soft-start when system rail is ramped up. When the system rail is below 2.2 V, the input
current is limited to is to 200 mA. After the system rises above 2.2 V, the device limits input current to the value
set by ILIM pin.
As a battery charger, the device deploys a highly efficient 1.5 MHz step-down switching regulator. The fixed
frequency oscillator keeps tight control of the switching frequency under all conditions of input voltage, battery
voltage, charge current and temperature, simplifying output filter design.
The device switches to PFM control at light load or when battery is below minimum system voltage setting or
charging is disabled.
8.3.3 Boost Mode Operation From Battery
The device supports boost converter operation to deliver power from the battery to other portable devices
through USB port. The maximum output current is up to 1.2 A. The boost operation can be enabled if the
conditions are valid:
1. BAT above V_{OTG_BAT}
2. VBUS less than BAT+V_SLEEP (in sleep mode)
3. Boost mode operation is enabled (OTG pin HIGH)
4. Voltage at TS (thermistor) pin is within acceptable range (V_BHOT < V_TS < V_BCOLD)
5. After 30-ms delay from boost mode enable
During boost mode, the VBUS output is 5.15 V and the output current can reach up to 1.2 A. The boost output is
maintained when BAT is above V_{OTG_BAT} threshold.
When OTG is enabled, the device starts up with PFM and later transits to PWM to minimize the overshoot.
8.3.4 Standalone Power Management
8.3.5 Power Path Management
The device accommodates a wide range of input sources from USB, wall adapter, to car charger. The device
provides automatic power path selection to supply the system (SYS) from input source (VBUS), battery (BAT), or
both.
8.3.6 Battery Charging Management
The device charges 1-cell Li-Ion battery with up to 3.0-A charge current for high capacity tablet battery. The 19.5-
mΩ BATFET improves charging efficiency and minimize the voltage drop during discharging.
8.3.6.1 Autonomous Charging Cycle
With battery charging is enabled (CE pin is LOW), the device autonomously completes a charging cycle. The
device default charging parameters are listed in Table 3.
Table 3. Charging Parameter Default Setting
Default Mode
Charging voltage
Charging current
Pre-charge current
Termination current
bq25606
VSET controlled
I_CHG controlled
5% of ICHG
5% of ICHG
18
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