Power battery management solution targets wearables

The solution supports batteries from 3.6 to 4.65V, and fast charge currents from 5 to 300mA, allowing wearables and industrial IoT applications to always be on without draining the battery.

The bq25120 maintains an always-on 1.8V operation using power path technology and a low Iq buck converter. A host MPU, such as a TI host MPU or Bluetooth radio, such as TI’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 solution features standby mode quiescent current of 50nA.

A configurable load switch/LDO output optimises the system by shutting off rarely used functions such as radios and displays to minimise battery drain. The solution also includes an integrated battery voltage monitor, enabling a state of charge indicator, buck converter and pushbutton control features.

The solution’s 2.5x2.5mm WCSP package enables a small footprint making it easier for designers to integrate it into sleek wearable designs. For an even more robust solution, designers can incorporate the CC2640 wireless MCU as it is the industry’s smallest QFN package solution with integrated Flash for Bluetooth Smart.

This feature maximises the energy delivered to the battery before completing the charging cycle, allowing batteries to draw a more robust full charge.

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. 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 12V boost and the TPS61240 with load connect, offers a 5V boost for heart rate monitor or small displays.

The bq25120 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 authorised distributors for $99.

The bq25120 charger is shipping in volume production and available through the TI Store and the company’s authorised distribution network. The product comes in a 2.5x2.5mm, WCSP package. The bq25120 is priced at $1.60 in 1,000-unit quantities.