Power chip

The NCV1072/NCP1075 products integrate a fixed frequency current mode controller with 670 V MOSFETs. Using PDIP-7 or SOT-223 encapsulation, the NCV1072/5 offers a high level of integration including soft-start, frequency dithering, short-circuit protection, cycle skipping, maximum peak current set point, slope compensation, and dynamic self-power supply (no auxiliary winding). Unlike other monolithic solutions, the NCV1072/5 are noise-free: during normal load operation, when switching at one of the available frequencies (65, 100, 130 kHz). When the demand for output power disappears, the IC will automatically enter frequency foldback mode, providing excellent energy efficiency at light loads. When power demand decreases further, it enters skip mode, reducing standby power consumption to no-load conditions. Protection features include: timers to detect overload or short circuit events, overvoltage protection with automatic recovery, and low input line voltage detection. To improve standby performance, connecting an auxiliary winding stops DSS operation, helping to reduce input power consumption on the high line to less than 50 mW.

The NCP1910 uses SO-24WB encapsulation, incorporating an advanced circuit for powering next generation ATX or flat panel TV converters. The NCP1910 features a 65 kHz continuous conduction mode power factor controller and LLC controller carrying high voltage drivers to power more than 85 off-line power supplies. To meet stringent energy efficiency requirements, the PFC circuit implements adjustable frequency foldback to reduce switching losses when the load becomes lighter. To handle the signal sequences required by the ATX or flat-panel TV specifications, the controller includes dedicated pins that enable handshaking between the secondary and primary sides. These signals include a power good line and also a control pin that switches the controller through an optocoupler. For safety, there is an additional OVP input to provide the necessary redundancy should the main feedback network drift. Finally, a fast fault input reacts immediately in the event of an overcurrent condition by triggering an auto-recovery soft-start sequence.

BiCMOS PFC/PWM Combo Controller 20-SOIC 0 to 70

UC3844 Current Mode PWM Controller