The APW7261 combine switch-mode battery charger and a boost regulator with fixed 3MHz switching frequency, which drives two integrated N-channel power MOSFETs. In battery charging, the high-efficiency step-down DC/DC converter is capable of delivering 1.5A output current over a wide input voltage range from 4V to 6V for APW7261, the step-down DC/DC converter is ideally suited for portable electronic devices that are powered from 1-cell Li-ion battery. The Charging parameters and operating modes can be programmed through an I2C interface. The APW7261 has high accuracy regulation of input current, charge current and charge voltage. It equipped with charge termination, and charge status monitoring for battery detection. The APW7261 charge the battery in three phases: conditioning, constant current and constant voltage. The APW7261 features Dynamic Power Management (DPM) mode to accomplish input power limiting. The input current is limited to the value set by the I2C host. This feature reduces battery charge current when the input power limit is reached to avoid overloading the AC adapter when supplying the load and the battery charger simultaneously. The charge termination is based on battery voltage, a programmed minimum current level and charge current termination bit set by the I2C host. If the battery voltage falls below an internal threshold, the APW7261 automatically restarts the charge cycle, and when the input voltage falls below the battery voltage, it will enter a low-quiescent current sleep mode. The APW7261 supports the thermal regulation and over temperature protection to maintain the junction temperature of 120oC by reducing charge current. The APW7261 can operate as a boost regulator. To support USB OTG device, APW7261 can provide VBUS (5.05V) by boosting the battery voltage. The APW7261 is available in1.73mmx2.0mm WLCSP20 packag