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 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 BQ25628E is a highly-integrated 2-A switchmode

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), 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 the BQ25628E a truly flexible

solution.