BQ25121A Low I
Q
Highly Integrated Battery Charge Management Solution
for Wearables and IoT
1 Features
• Increases System Operation Time Between
Charges
– Configurable 300-mA Buck Regulator
(2.5-V Default)
– 700 nA (typical) Iq with Buck Converter
Enabled (No Load)
– Configurable Load Switch or 100mA LDO
Output (Load Switch by Default)
– Up to 300-mA Charge Current for Fast
Charging
– 0.5% Accurate Battery Voltage Regulation
(Configurable from 3.6 V to 4.65 V in 10-mV
Steps)
– Configurable Termination Current Down to
500 µA
– Simple Voltage Based Battery Monitor
– Watchdog Timer Disabled
• Highly Integrated Solution with Small Footprint
– 2.5 mm x 2.5 mm WCSP Package and 6
External Components for Minimal Solution
– Push-Button Wake-Up and Reset with
Adjustable Timers
– Power Path Management for Powering the
System and Charging the Battery
– Power Path Management enables <50 nA Ship
Mode Battery Quiescent Current for Longest
Shelf Life
– Battery Charger Operates from 3.4 V – 5.5 V
IN
(5.5-V OVP / 20-V Tolerant)
– Dedicated Pins for Input Current Limit, Charge
Current, Termination Current, and Status
Output
• I
2
C Communication Control
– Charge Voltage and Current
– Termination Threshold
– Input Current Limit
– VINDPM Threshold
– Timer Options
– Load Switch Control
– System Output Voltage Adjustment
– LDO Output Voltage Adjustment
• Safety-Related Certification:
– TUV IEC 62368-1 Certification
2 Applications
• Smart Watches and other Wearable Devices
• Fitness Accessories
• Health Monitoring Medical Accessories
• Rechargeable Toys
3 Description
The BQ25121A is a highly integrated battery charge
management IC that integrates the most common
functions for wearable devices: Linear charger,
regulated output, load switch, manual reset with timer,
and battery voltage monitor. The integrated buck
converter is a high efficiency, low I
Q
switcher using
DCS-Control
™
that extends light load efficiency down
to 10-µA load currents. The low quiescent current
during operation and shutdown enables maximum
battery life. The device supports charge currents from
5 mA to 300 mA.
Device Information
PART NUMBER
PACKAGE
BODY SIZE (NOM)
BQ25121A
DSBGA (25)
2.50 mm x 2.50 mm
(1)
For all available packages, see the orderable addendum at
the end of the data sheet.
GND
HOST
SDA
SCL
INT
SW
BAT
MR
BQ25121A
MCU /
SYSTEM
-
+
NTC
TS
LS / LDO
<100mA
Load
IN
SYS
RESET
LSCTRL
VINLS
Unregulated
Load
PMID
PG
IPRETERM
ISET
ILIM
CD
IN
Simplified Schematic
SLUSDA7A – APRIL 2018 – REVISED JANUARY 2021
Copyright © 2021 Texas Instruments Incorporated
1
Product Folder Links:
SLUSDA7A – APRIL 2018 – REVISED JANUARY 2021
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.
