1 Features
• Wide input voltage operating range: 4.4V to 70V
• Wide battery voltage operating range: up-to 70V
with multi-chemistry support:
– 1- to 14-cell Li-ion charge profile
– 1- to 16-cell LiFePO4 charge profile
– Up-to 70V supercapacitor charging
• Synchronous buck charge controller with NFET
drivers
– Adjustable fSW from 200kHz to 600kHz
– Switching frequency dithering for EMI noise
reduction (DRSS)
– 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 0.8A to 40A with 100mA/step using 2.5mΩ
resistor
• High accuracy
– ±0.5% charge voltage regulation
– ±3% charge/input current regulation
– ±2% input voltage 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
– Battery overvoltage and overcurrent protection
– Charging safety timer
– Thermal shutdown
• Status outputs
– Input power present status (PG)
– Charger operation status (STAT1, STAT2)
• Package
– 36-pin 5mm × 6mm QFN

2 Applications
• Portable Power Station
• Energy Infrastructure
• Solar Backup Charger

3 Description
The BQ25822 is a wide input voltage, switched-mode
buck Li-Ion, Li-polymer, or LiFePO4 battery charge
controller with bidirectional power flow support.
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 input terminal voltage with
an added constant current loop for protection.
Besides the I2C host-controlled charging mode, the
device also supports standalone charging mode via
resistor programmable limits. Input current, charge
current, and charge voltage regulation targets can be
set via the ILIM_HIZ, ICHG, and FB pins, respectively.