The BQ25620 and BQ25622 are highly-integrated 3.5A switch-mode battery charge management and system power path management devices for single cell Li-Ion and Li-polymer batteries. The solution is highly integrated with built-in current sensing, loop compensation, input reverse-blocking FET (RBFET, Q1), high-side switching FET (HSFET, Q2), low-side switching FET (LSFET, Q3), and battery FET (BATFET, Q4) between system and battery. The devices use narrow VDC power path management, regulating the system slightly above the battery voltage without dropping below a configurable minimum system voltage. The low impedance power path optimizes switch-mode operation efficiency, reduces battery charging time, extends battery life during discharging phase, and the ultra-low 0.15µA ship mode current extends battery shelf life. The I2C serial interface with charging and system settings makes the BQ25620 and BQ25622 truly flexible solutions.

The BQ25620 supports a wide range of input sources, including standard USB host port, USB charging port, and USB compliant high voltage adapter. It sets the default input current limit based on the built-in D+/D- USB adapter detection interface. BQ25622 has an ILIM pin to set the default input current limit and a TS_BIAS pin for controlled thermistor bias. The device is compliant with USB 2.0 and USB 3.0 power specifications for input current and voltage regulation and meets USB On-the-Go (OTG) operation power rating specification with constant current limit up to 2.4A.

The power path management regulates the system slightly above battery voltage but does not drop below the programmable minimum system voltage. With this feature, the system maintains operation even when the battery is completely depleted or removed. When the input current limit or input voltage limit is reached, the power path management automatically reduces the charge current. As the system load continues to increase, the battery starts to discharge until the system power requirement is met. This supplement mode prevents overloading the input source.Read more