1 Features

• Wide input voltage operating range: 4.4V to 70V

• Synchronous buck charge controller with NFET

drivers

– Adjustable switching frequency from 200kHz to

600kHz

– Optional synchronization to external clock

– Integrated loop compensation with soft start

– Optional gate driver supply input for optimized

efficiency

• Bidirectional converter operation (Reverse Mode)

supporting USB-PD Extended Power Range (EPR)

– Adjustable input voltage (VAC) regulation from

3.3V to 65V with 20mV/step

– Adjustable input current regulation (RAC_SNS)

from 400mA to 20A with 50mA/step using 5mΩ

resistor

• Direct power path management for highest

efficiency to power system

– System power selection from adapter or battery

– Dynamic power management

– All N-channel FET drivers

• High accuracy

– ±0.5% charge voltage regulation

– ±3% charge current regulation

– ±3% input current regulation

• I2C controlled for optimal system performance with

resistor-programmable option

– Hardware adjustable input and output current

limits

• Integrated 16-bit ADC for voltage, current, and

temperature monitoring

• High safety integration

– Adjustable input overvoltage and undervoltage

protection

– Overvoltage and overcurrent protection

– Thermal shutdown

• Status outputs

– Adapter present status (PG)

– Operation status

• Package

– 36-pin 5mm × 6mm QFN

2 Applications

• Cordless power and garden tools

• Solar backup charger

• Energy storage systems

• Drone

• Ultrasound

• X-ray systems

• Electronic hospital beds and bed control

• Multiparameter patient monitors

• Vacuum Robot

3 Description

The BQ25820 is a wide input voltage, switchedmode

buck Li-Ion, Li-polymer, or LiFePO4 battery

charge controller with direct power path control.

The device offers high-efficiency battery charging

over a wide voltage range with accurate charge

current and charge voltage regulation, in addition to

automatic charge preconditioning, termination, and

charge status indication. The device integrates all the

loop compensation for the buck converter, thereby

providing a high density solution with ease of use.

In reverse mode, the device draws power from the

battery and regulates the SYS terminal voltage.