TI-BQ25123.pdf

BQ25123 700-nA Low Iq Highly Integrated Battery Charge Management Solution for

Wearables

1 Features

• Increases system operation time between charges

– Configurable 300-mA buck regulator

– 700-nA (typical) Iq with buck converter enabled

(no load)

– Configurable load switch or 100-mA LDO

output

– Simple voltage based battery monitor

• 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

• I

2

C communication control

– Charge voltage and current

– Termination threshold

– Input current limit

– VINDPM threshold

– Timer options

– Load switch control

– Controls for interrupts for faults and status

– System output voltage adjustment

2 Applications

• Smart watches and other wearable devices

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

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

PART NUMBER PACKAGE BODY SIZE (NOM)

(1) For all available packages, see the orderable addendum at

the end of the data sheet.

Simplified Schematic

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.

Changes from Revision * (January 2018) to Revision A (May 2021) Page

• Updated the numbering format for tables, figures, and cross-references throughout the document..................1

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5 Description (continued)

The battery is charged using a standard Li-Ion charge profile with three phases: precharge, constant current and

reset with timer allows mutliple different configuration options for wake are reset optimization. A simple voltage

based monitor provides battery level information to the host in 2% increments from 60% to 100% of the

programmed V

6 Device Comparison Table

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7 Pin Configuration and Functions

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SYS B5 I

System Voltage Sense Connection. Connect SYS to the system output at the output bulk

capacitors. Bypass SYS locally with at least 4.7 µF of effective ceramic capacitance.

TS C3 I

Battery Pack NTC Monitor. Connect TS to the center tap of a resistor divider from VIN to

GND. The NTC is connected from TS to GND. The TS function provides four thresholds for

JEITA compatibility. TS faults are reported by the I

C interface during charge mode.

VINLS B4, C4 I

Input to the Load Switch / LDO output. Connect 1 µF of effective ceramic capacitance from

this pin to GND.

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