Tiny battery management IC targets wearables and IoT apps
The bq25120 integrates a linear charger, configurable LDO, load switch, buck converter, push-button control and battery voltage monitor. It supports batteries from 3.6 to 4.65 V, and fast charge currents from 5 to 300 mA, allowing wearables and industrial Internet of Things (IoT) applications to always be on without draining the battery.
The bq25120 maintains an always-on 1.8-V operation using power path technology and a low-Iq buck converter. A host microprocessor, such as a TI host microprocessor or Bluetooth radio, such as the company’s SimpleLink Bluetooth Smart CC2640 wireless MCU, is able to continue running during recharging by not extracting "empty energy." Designers can also achieve the longest battery shelf life as the system features standby mode quiescent current of 50 nA.
The bq25120 has a configurable load switch/LDO output that optimizes the system by shutting off rarely used functions such as radios and displays to minimize battery drain. The device also includes an integrated battery voltage monitor, enabling a state of charge indicator, buck converter and pushbutton control features.
The device, which comes in a 2.5 x 2.5-mm WCSP, enables a small footprint making it easier for designers to integrate it into sleek wearable designs. For an even more robust system, designers can incorporate the CC2640 wireless MCU as it is the industry’s smallest QFN package with integrated Flash for Bluetooth Smart.
Accurate charge termination down to 500 µA maximizes the energy delivered to the battery before completing the charging cycle, allowing batteries to draw a more robust full charge. Offering a high degree of flexibility, the bq25120’s I2C programming interface gives designers the ability to set key parameters including battery charger voltage, current, termination threshold, input current limit, load switch control, flexible timer and reset options and more.
The bq25120 can be used in conjunction with devices to integrate more end application features. An ultra-low Iq step-down converter, the TPS62743 can be used for additional buck output. Boost converters can also be used for display integration. The TPS61046 offers a 12-V boost and the TPS61240 with load connect, offers a 5-V boost for heart rate monitor or small displays.
The bq25120 evaluation module (EVM) allows customers to speed time to market by quickly and easily evaluate device features and performance. The BQ25120EVM-731 is available from the TI Store and authorized distributors for US $99.
BQ25120 information page
BQ25120EVM-731 evaluation module information page
Texas Instruments: www.ti.com