1 Features
• 800-mA Power path linear battery charger
– 3.0-V to 5.9-V input voltage operating range
optimized for battery to battery charging and
USB adapter
– 25-V tolerant input voltage
– Configurable battery regulation voltage with
0.5% accuracy from 3.6 V to 4.65 V in 10-mV
steps
– 5-mA to 800-mA configurable fast charge
current
– 55-mΩ battery FET ON resistance
– Up to 2.5-A discharge current to support high
system loads
– Configurable termination current down to 0.5
mA
– Configurable NTC charging profile thresholds
including JEITA support
– Power cycle and advanced reset mechanisms
to recover system
• Power path management for powering the system
and charging the battery
– Regulated system voltage (SYS) ranging from
4.4 V to 4.9 V in addition to battery voltage
tracking and input pass-though options
– Configurable input current limit
– Selectable adapter or battery power for system
– Dynamic power path management optimizes
charging from weak adapters
• Ultra low quiescent current modes
– 30-nA Shutdown mode
– 3.2-μA Ship mode with button press wake
– 4 μA in Battery Only mode
– 45-μA input adapter Iq in Sleep mode
• One push-button wake-up and reset input
• Integrated fault protection
– Input overvoltage protection (VIN_OVP)
– Battery undervoltage protection (VBUVLO)
– 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
– System short protection
– System overvoltage protection

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 BQ21080 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 800-mA charging
and system loads of up to 2.5 A.