Texas Instruments rolled out a new battery charger IC that boosts the run time of compact consumer and medical electronics while cutting charging times and filling up more of a battery’s available capacity. The new switching battery charger IC can add more than 5% of run time to the average battery crammed inside wearables, earbuds, patient monitoring devices and wireless charging cases, the Dallas, Texas-based company said.
Once a lithium-ion battery is fully charged, energy must be shut down to prevent overcharging, which can not only degrade the battery’s capacity but can also lead to dangerous conditions that cause it to overheat. The BQ25619 is designed to limit how much current is lost when the charge entering the battery is terminated—called the termination current. The IC supports 20 mA in termination current. Other chips on the market draw more than 60 mA, Texas Instruments said.
The BQ25619 also limits standby, or quiescent, current to 6 uA, which doubles the battery’s shelf life. The charger IC for single-cell lithium-ion or lithium-polymer batteries combines the buck charger and boost regulator into a single solution that can handle charging, discharging and voltage protection using a single inductor. That saves space for electronics engineers making medical electronics for monitoring patient health or compact consumer gadgets, like the Apple Watch.
The input currents supported by the 1.5-A battery charger IC range from 100 mA to 3.5 A while voltages range from 4V to 13.5V. The battery charger supports a wide range of input sources, ranging from USB chargers and adapters or even wireless charging cases. Apple in March released a wireless charging case that holds 24 hours of battery life for its AirPods earbuds, introduced in 2016. Samsung has also started selling a wireless charging case for use with its Galaxy Buds.
The charger IC, slapped inside a 4mm by 4mm by 0.75mm WQFN package, adds about 7% to the average battery’s run time before having to be recharged. Texas Instruments is aiming the chip at electronics engineers trying to get more and more run time out of smaller and smaller batteries. The 24-pin BQ25619 has started selling for $1.45 each in 1,000-unit orders. The company plans to roll out the 30-pin BQ25618 in a smaller WCSP package in the third quarter of 2019.