BQ25606 Datasheet, PDF (24/43 Pages) Texas Instruments – Standalone 3.0-A, Single Cell Battery Charger With 40V Over Voltage Protection Controller

bq25606
SLUSCK6 – MAY 2017
www.ti.com
8.3.8.3.3 Boost Mode Overvoltage Protection
When the VBUS voltage rises above regulation target and exceeds VOTG_OVP, the device stop switching.
8.3.8.4 Thermal Regulation and Thermal Shutdown
8.3.8.4.1 Thermal Protection in Buck Mode
The bq25606 monitors the internal junction temperature T_J to avoid overheat the chip and limits the IC surface
temperature in buck mode. When the internal junction temperature exceeds thermal regulation limit (110°C), the
device lowers down the charge current. During thermal regulation, the actual charging current is usually below
the programmed battery charging current. Therefore, termination is disabled, the safety timer runs at half the
clock rate.
8.3.8.4.2 Thermal Protection in Boost Mode
The device monitors the internal junction temperature to provide thermal shutdown during boost mode. When IC
junction temperature exceeds T_SHUT (160ºC), the boost mode is disabled and BATFET is turned off. When IC
junction temperature is below T_SHUT(160ºC) - T_{SHUT_HYS} (30ºC), the BATFET is enabled automatically to allow
system to restore .
8.3.8.5 Battery Protection
8.3.8.5.1 Battery overvoltage Protection (BATOVP)
The battery overvoltage limit is clamped at 4% above the battery regulation voltage. When battery over voltage
occurs, the charger device immediately disables charging.
8.3.8.5.2 Battery Over-Discharge Protection
When battery is discharged below V_{BAT_DPL_FALL}, the BATFET is turned off to protect battery from over discharge.
To recover from over-discharge latch-off, an input source plug-in is required at VBUS. The battery is charged
with I_SHORT (typically 100 mA) current when the VBAT < VSHORT, or precharge current as set by 5% of ICHG
when the battery voltage is between V_SHORTZ and V_{BAT_LOWV}.
8.3.8.5.3 System Over-Current Protection
When the system is shorted or significantly overloaded (IBAT > IBATOP) and the current exceeds BATFET
overcurrent limit, the BATFET latches off. The BATFET latch can be reset with VBUS plug-in.
9 Application and Implementation
NOTE
information in the following applications sections is not part of the TI component
specification, and TI does not warrant its accuracy or completeness. TI’s customers are
responsible for determining suitability of components for their purposes. Customers should
validate and test their design implementation to confirm system functionality.
9.1 Application information
A typical application consists of the device configured as a stand-alone power path management device and a
single cell battery charger for Li-Ion and Li-polymer batteries used in a wide range of smart phones and other
portable devices. It integrates an input reverse-block FET (RBFET, Q1), high-side switching FET (HSFET, Q2),
low-side switching FET (LSFET, Q3), and battery FET (BATFET Q4) between the system and battery. The
device also integrates a bootstrap diode for the high-side gate drive.
External OVPFET is optional. When external OVP is not used, short the VBUS and VAC pins and allow ACDRV
pin to float (as shown in Figure 19)
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