USB switching charger IC integrates fuel gauge

The charger is based on a 3MHz DC/DC converter with small 1µH inductors and uses the fast and reliable constant current (CC) and constant voltage (CV) method for charging single-cell Lithium-ion batteries, with a maximum charging current of 2A. The advanced charger achieves over 90% efficiency, which helps minimise heat buildup within increasingly compact low-cost smartphones. An integrated ARM Cortex M0 processor supports superior digital processing capabilities for power management and the integrated fuel gauge functionality.

The DA9150 supports completely autonomous charging from a 5V input supply and includes a power supply adaptation feature which enables it to charge from a broad range of power supplies – including 5V USB battery charging specification v1.2 compliant supplies – and find the optimal operating point. The integrated over-voltage protection allows voltages of up to 24V.

In order to supply USB applications like LTE data dongles or USB memory sticks, the buck converter can operate in reverse mode, which enables the DA9150 to supply 5V to VBUS for USB OTG functionality with an output current of up to 1A.

The DA9150 features a power path technology, which is a new and innovative regulation scheme achieving the benefits of power-path management without using a switch between the system supply and the battery. For better system power management, it introduces innovative monitoring features using a 10-bit ADC in combination with four GPIO pins. System parameters such as real charging current, VBUS and system voltages, power consumption of the application and temperatures are made available to the processor via an I2C interface. This transparency together with the accurate fuel gauge allows the application processor to better manage and optimise battery life time.

The DA9150 includes many safety relevant features such as temperature-dependent charge profiles compliant with the JEITA standard, thermal supervision of the charger itself, short circuit protection, and safety timers to protect the battery. The device operates in a temperature range from -40 to +85°C and comes in a small 4x4mm QFN package.

Udo Kratz, Senior Vice President and General Manager, Business Group Mobile Systems, Dialog Semiconductor, comments: “The concept of combining a fuel gauge with charging functions exploits many synergies of battery-related functions within a smartphone design. Furthermore, the introduction of the DA9150 supports our ongoing strategy of low-cost smartphone initiatives to address the fast-growing Chinese LTE smartphone market."