NCS1002A

NCS1002A Constant Voltage / Constant Current Secondary­Side Controller Description The NCS1002A is a performance upgrade from the NCS1002 focused on reducing power consumption in applications that require more efficient operation. It 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 NCS1002A 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 divider that 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 adequately rated in terms of power dissipation. The NCS1002A comes in a small 8−pin SOIC package and is ideal for space-shrunk applications such as battery chargers. Features Low Input Offset Voltage: 0.5 mV, Typ Input Common-Mode Range includes Ground Low Quiescent Current: 75 mA per Op Amp at VCC = 5 V Large Output Voltage Swing Wide Power Supply Range: 3 V to 36 V High ESD Protection: 2 kV This i...