Power chip

The NCP1077A and NCP1077B products integrate a fixed frequency current mode controller with 700 V MOSFETs. It uses two different pin outputs of the very common PDIP™7 encapsulation, which provides a high degree 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 required). Unlike other monolithic solutions, the NCP1077A and NCP1077B are noiseless: during normal load operation, the part switches at a usable frequency (65 or 100 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. Input line voltage detection prevents severe runaway under low input voltage conditions (undervoltage) as well as over high input lines (AC line overvoltage protection). This also enables the overpower protection to compensate for any internal delays at high input voltage conditions, optimizing the maximum output current capability. 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 FSFR-XS series includes highly integrated power switches for high energy efficiency half-bridge resonant converters. The FSFR-XS series provides everything needed to build a reliable and robust resonant converter, simplifying design while increasing productivity and performance. The FSFR-XS series combines a power MOSFET with a fast recovery type body diode, a high side gate drive circuit, a precise current controlled oscillator, a frequency limit circuit, soft start and built-in protection functions. This high-side gate drive circuit features common-mode noise suppression, ensuring stable operation and excellent noise immunity. The MOSFET's fast recovery body diode increases reliability against abnormal operating conditions while minimizing reverse recovery effects. The use of Zero Voltage Switching (ZVS) technology greatly reduces switching losses and significantly improves energy efficiency. ZVS also significantly reduces switching noise, allowing the use of small electromagnetic interference (EMI) filters. The FSFR-XS series can be applied in resonant converter topologies such as series resonant, parallel resonant and LLC resonant converters.