I²C 1-cell 5A buck battery charger with USB Type-C® detection

The BQ25630 is a highly-integrated 5A switch-mode battery charge management and system power path management device 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), switching FETs (HSFET - Q2 and LSFET - Q3), and battery FET (BATFET, Q4) between system and battery. It integrates a USB Type-C controller with Dual-Role Power with Try.SNK and Try.SRC support. It uses NVDC 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 efficiency, reduces battery charging time and 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 BQ25630 a truly flexible solution.

The BQ25630 supports a wide range of input sources, including standard USB host port, USB charging port, USB-C adapters, and USB compliant high voltage adapter. It integrates a USB Type-C controller (CC1/CC2) with USB-C Detection up to 15W and sets the current limit according to the detection result. The BQ25630 supports Dual-Role Power with Try.SNK and Try.SRC. It also includes BC1.2 detection using the built-in D+/D- USB adapter detection interface. It is compliant with USB 2.0 and USB 3.0 power specifications for input current and voltage regulation. In addition, the Input Current Optimizer (ICO) supports the detection of maximum power point of the input source without overload. The device also meets USB On-the-Go (OTG) operation power rating specification with constant current limit up to 3.2A.

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. If the system load continues to increase, the power path discharges the battery until the system power requirement is met. This supplement mode prevents overloading the input source.

The device initiates and completes a charging cycle without host control. By sensing the battery voltage, it charges the battery in four different phases: trickle charge, pre-charge, constant current (CC) charge and constant voltage (CV) charge. At the end of the charging cycle, the charger automatically terminates when the charge current is below a preset threshold and the battery voltage is higher than the recharge threshold. Termination is supported for TS pin COOL, PRECOOL, NORMAL, WARM and PREWARM temperature zones. When the full battery voltage falls below the programmable recharge threshold, the charger automatically starts a new charging cycle.

The charger provides various safety features for battery charging and system operations, including battery negative temperature coefficient (NTC) thermistor monitoring, charging safety timer and overvoltage and overcurrent protections. The thermal regulation reduces charge current when the junction temperature exceeds the programmable threshold. Other safety features include battery temperature sensing for charge mode and OTG boost mode, thermal shutdown and input UVLO and over-voltage protection. The PG output indicates if a good power source is present and above the programmable PGTH value. The INT output immediately notifies the host when a fault occurs or status changes.

The device also provides a 12-bit analog-to-digital converter (ADC) for monitoring charge current and input/battery/system (VBUS, BAT, SYS, TS) voltages. The QON pin provides BATFET enable and reset control to exit ultra-low power mode or initiate a full system reset.

BQ25630 is available in a 30-ball, 2.3mm × 2.4mm DSBGA package.