Switching charger IC targets USB powered smartphones
An integrated ARM Cortex M0 processor supports superior digital processing capabilities for power management and the integrated fuel gauge functionality. The fuel gauge measures the state of charge of the battery with 99 per cent accuracy, allowing system firmware to maximise battery run time for consumers who increasingly depend on portable devices in their daily life.
The DA9150 charger is based on a 3 MHz 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 2 A. The advanced charger achieves over 90% efficiency, which helps minimise heat buildup within increasingly compact low-cost smartphones. DA9150 supports completely autonomous charging from a 5 V input supply and includes a power supply adaptation feature which enables it to charge from a broad range of power supplies – including 5 V USB battery charging specification v1.2 compliant supplies – and find the optimal operating point. The integrated over-voltage protection allows voltages of up to 24 V.
In order to supply USB applications like LTE data dongles or USB memory sticks, the buck converter can operate in reverse mode, which enables DA9150 to supply 5 V to VBUS for USB OTG functionality with an output current of up to 1 A.
The concept of combining a fuel gauge with charging functions exploits many synergies of battery-related functions within a smartphone design.
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 the DA9150 introduces innovative monitoring features using a 10-Bit ADC in combination with 4 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. The transparency together with the accurate fuel gauge allows the application processor to better manage and optimize 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 of -40°C to 85°C and comes in a 4×4 mm QFN package.
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