NCP1075P100G

The NCP1072/5 achieves excellent efficiency at light loads by automatically entering frequency foldback mode when the output power demand diminishes. This mode allows the controller to reduce its switching frequency down to 25 kHz for a feedback level of I FBfold(end), which is roughly 100 /C0109A. If the power continues to drop, the controller enters classical skip-cycle mode, where unnecessary switching cycles are skipped to drastically reduce power wastage during light load conditions .

The key features of the NCP1072/NCP1075 products include: - Current-mode operation with a current-mode control architecture . - Integration of a 700 V Power MOSFET with a low RDS(on) value, allowing for the construction of power supplies up to 10 W operated on universal mains . - Dynamic Self-Supply capability due to the internal high voltage current source, eliminating the need for an auxiliary winding . - Integration of a fixed frequency current mode controller with a 700 V MOSFET in a PDIP-7 or SOT-223 package . - Additional features such as soft-start, frequency-jittering, short-circuit protection, skip-cycle, maximum peak current set point, ramp compensation, and quiet operation during nominal load operation . - Automatic frequency foldback mode for excellent efficiency at light loads .

The protection features of the NCP1072/5 include a timer to detect overload or short-circuit events, overvoltage protection with auto-recovery, and AC input line voltage detection. Additionally, the NCP1072/5 has auto-recovery output short circuit protection with a recovery duration of about 420 ms. In case of a short-circuit or overload, the NCP107X protects itself and the power supply via a low-frequency burst mode. The NCP107X also offers auto-recovery overvoltage protection to prevent output voltage runaway when the optocoupler fails. These protection features ensure the safe and reliable operation of the NCP1072/5 high-voltage switcher for low power offline SMPS.