The LTC1980 integrates PWM power control for charging a battery and converting the battery voltage to a regulated output or simultaneously charging the battery while powering system load from an unregulated AC wall adapter. Combining these features into a single IC produces a smaller area and lower cost solution compared to presently available multi-IC solutions. The LTC1980 shares the discrete components for both the battery charger and the DC/DC converter thus minimizing size and cost relative to dual controller solutions. Both the battery charger and DC/DC converter use a current mode flyback topology for high efficiency and excellent transient response. Optional Burst Mode operation and power-down mode allow power density, efficiency and output ripple to be tailored to the application.