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.