BQ25628RYKR

The BQ25628 and BQ25629 are highly-integrated 2-A 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 device uses 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 0.15-μA ship mode current extends battery shelf life. The I²C serial interface with charging and system settings makes BQ25628 and BQ25629 truly flexible solutions. The BQ25628 supports a wide range of input sources, including standard USB host port, USB charging port, and USB compliant high voltage adapter. The BQ25629 has the ILIM pin to set the default input current limit and 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 the USB On-the-Go (OTG) operation power rating specification up to 2.0 A. 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. The BQ25628 and BQ25629 power an accessory attached to PMID either directly from the adapter or from the battery in either boost or bypass OTG modes. Boost OTG provides a regulated voltage at PMID from the battery via boost operation in the converter. Bypass OTG provides a direct path from the battery to PMID for highest efficiency. The BQ25628 and BQ25629 may be configured to automatically transition into boost OTG mode when the adapter is removed, and back into forward charging when the adapter is attached in order to power PMID in either configuration without host intervention. In forward charging, boost OTG and bypass OTG, the PMID_GD signal indicates PMID voltage and current are within accepted ranges. PMID_GD may be used to drive an external PMOS FET to protect attached accessories by disconnecting them from PMID if an out-of-range voltage or current is detected.

Applications

• Consumer Wearables
• Smartwatch
• Portable Speakers
• TWS Earphone

Key features

• High-efficiency, 1.5-MHz, synchronous switching mode buck charger for single cell battery
• >90% efficiency down to 25-mA output current from 5-V input
• Charge termination from
• Flexible JEITA profile for safe charging over temperature
• BATFET control to support shutdown, ship mode and full system reset
• 1.5-μA quiescent current in battery only mode – 0.15-μA battery leakage current in ship mode 0.1-μA battery leakage current in shutdown
• Supports Boost Mode operation to power accesory – Boost Mode operation supporting 3.84-V to 5.2-V output >90% boost efficiency down to 100-mA boost current for 5-V PMID
• Supports a wide range of input sources
• 3.9-V to 18-V wide input operating voltage range with 26-V absolute maximum input voltage
• Maximizes source power with input voltage regulation (VINDPM) and input current regulation (IINDPM)
• VINDPM threshold automatically tracks battery voltage
• Efficient battery operation with 15-mΩ BATFET
• Narrow VDC (NVDC) power path management
• System instant-on with depleted or no battery
• Battery supplement when adapter is fully loaded
• Hearing Aid or TWS Charging Case