SY6974 Datasheet | Silergy

Application Note: SY6974 3A, Single Cell Li-Ion DC/DC Switching Charger with I2C Control, USB Detection and OTG JEITA pliant, Power Path Management General Description The SY6974 is a fully-integrated switching battery charger with system power path management devices for single cell Li-ion and Li-polymer battery in a wide range of tablet and other portable devices. Its low impedance power path optimizes switching conversion efficiency, reduces battery charging time and extends battery life during the discharging mode. The I2C serial interface with charging and system settings makes the device a truly flexible solution. The device supports a wide range of input sources, including standard USB port and high power DC adapter. The SY6974 takes the result from detection circuit in the system, such as USB PHY device. The SY6974 meets USB On-the-Go operation power rating specification by supplying 5.15V (programmable) on BUS with current limit up to 1.2A (programmable). The power path management regulates the system voltage slightly above battery voltage but does not drop below 3.5V minimum system voltage (programmable). With this feature, the switching converter will keep working to support the system load even when the battery is pletely depleted or removed. When the input current limit or voltage limit is reached, the power path management will reduce the charging current to zero firstly. If the system load continues to increase, the power path will discharge the battery to provide the power required by system. This supplement mode operation prevents overloading the input source. The device initiates and pletes a charging cycle without software control. It automatically detects the battery voltage and charges the battery in five phases: battery short, preconditioning, constant current and constant voltage and top-off charging (optional). At the end of the charging cycle, the charger automatically will terminate when the charge current is below a preset...