1 Features

• High-efficiency 5-A, 1.5-MHz, synchronous switch

mode buck charger for single cell battery

– >90 efficiency down to 10-mA output current

from 5-V input

– Charge current up to 5 A in 80-mA steps

– Charge termination from 30 to 1000 mA in 10-

mA steps

– Flexible JEITA profile for safe charging over

temperature

• BATFET control to support shutdown and full

system reset

– 1.5-μA quiescent current in battery only mode

– 100-nA battery leakage current in shutdown

• Supports USB On-The-Go (OTG)

– Boost mode operation with 3.84-V to 9.6-V

output

– Programmable current limit up to 3.2 A

• 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

– VINDPM threshold automatically tracks battery

voltage

– Input Current Optimizer (ICO) to maximize input

power without overloading adapters

• Efficient battery operation with 7-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, and

temperature monitoring

– ADCIN pin for external signal up-to 1 V

• High accuracy

– ±0.5 (TBD) charge voltage regulation

– ±5 charge current regulation

– ±5 input current regulation

• Safety

– Battery temperature sensing

– Thermal regulation and thermal shutdown

– Battery/converter overcurrent protection

– Charging safety timer

2 Applications

• Gaming and Computer Accessories

• Smart Phone, Tablet

• IP Camera, EPOS

• Portable Medical Equipment

• Consumer Wearables, Smartwatch

• Portable Speakers, TWS Earphone

3 Description

The BQ25638 is a highly-integrated 5-A switch-mode

battery charge management and system power path

management device for single cell Li-Ion and Lipolymer

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. 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 switch-mode operation efficiency,

reduces battery charging time and extends battery life

during discharging phase. The I2C serial interface with

charging and system settings makes BQ25638 a truly

flexible solution.