Overview: NCP1124, NCP1126, NCP1129 High Voltage Switcher for Offline Power Supplies The NCP112x products integrates a fixed−frequency peak current mode controller with a low on−resistance, 650 V MOSFET. Available in a PDIP−7 package, the NCP112x offers a high level of integration, including soft−start, frequency−jittering, short−circuit protection, thermal shutdown protection, frequency foldback mode and skip−cycle to reduce power consumption in light load condition, peak current mode control with adjustable internal ramp pensation and adjustable peak current set point.
During nominal load operation, the part switches at one of the available frequencies (65 or 100 kHz). When the output power demand diminishes, the IC automatically enters frequency foldback mode and provides excellent efficiency at light loads. When the power demand reduces further, it enters into a skip mode to reduce the standby consumption down to no load condition.
