1 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

? Flexible autonomous or I2C-controlled modes

? Integrated 12-bit ADC for voltage, current,

temperature monitoring

? High Accuracy

– ±0.4 charge voltage regulation

– ±5 charge current regulation

– ±5 input current regulation

? Safety

– Thermal regulation and thermal shutdown

– Input, system, and battery overvoltage

protection

– Battery, and converter overcurrent protection

– Charging safety timer

2 Applications

? Consumer Wearables, Smartwatch

? Portable Speakers, TWS Earphone

? Hearing Aid or TWS Charging Case

3 Description

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), lowside

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.