1 Features
• 1A linear battery charger
– 3.0V to 5.5V input voltage operating range for
battery-to-battery charging and USB adapters
– Configurable battery regulation voltage with
0.5% accuracy from 3.6V to 4.65V in 10mV
steps
– Li-ion, Li-Poly, and LiFePO4 chemistries
support
– 5mA to 1A configurable fast charge current
– 55mΩ battery FET ON resistance
– Up to 3A discharge current to support high
system loads
– Configurable NTC charging profile thresholds
including JEITA support
• Power path management for powering the system
and charging the battery
– Regulated system voltage (SYS) ranging from
4.4V to 4.9V addition to battery voltage tracking
and input pass-though options
– Battery Tracking input voltage dynamic power
management (VINDPM) for high impedance
input sources
• Ultra low quiescent current
– 4μA in Battery Only mode
– 30μA Input adapter Iq in sleep mode
• One push-button wake-up and reset input
• Integrated fault protection
– Input overvoltage protection (VIN_OVP)
– Battery short protection (BATSC)
– Battery overcurrent protection (BATOCP)
– Input current limit protection (ILIM)
– Thermal regulation (TREG) and thermal
shutdown (TSHUT)
– Battery thermal fault protection (TS)
– Watchdog and safety timer fault

2 Applications
• TWS headset and charging case
• Smart glasses, AR and VR
• Smart watches and other wearable devices
• Retail automation and payment
• Building automation

3 Description
The BQ21088 is a linear battery charger IC focusing
on small solution size and low quiescent current for
extending battery life. The device is available in an
8-ball chipscale package which does not need HDI
PCB process for fabrication thereby reducing the PCB
cost. The device can support up to 1A charging and
system loads of up to 3A.