The NCS1002 Constant Voltage and Constant Current Secondary Controller is a highly integrated solution for Switching Mode Power Supply (SMPS) applications requiring a dual control loop to perform Constant Voltage (CV) and Constant Current (CC) regulation. The NCS1002 integrates a 2.5 V voltage reference and two precision op amps. The voltage reference, along with Op Amp 1, is the core of the voltage control loop. Op Amp 2 is an independent, uncommitted amplifier specifically designed for the current control.Key external components needed to complete the two control loops are: (a)A resistor dividerthat senses the output of the power supply (battery charger) and fixes the voltage regulation set point at the specified value. (b) A sense resistor that feeds the current sensing circuit with a voltage proportional to the DC output current. This resistor determines the current regulation set point and must be adquately rated in terms of power dissipation. The NCS1002 comes in a small 8-pin SOIC package and is ideal for space-shrunk applications such as battery chargers.