The NCP1050 through NCP1055 are monolithic high voltage regulators that enable end product equipment to be compliant with low standby power requirements. This device series combines the required converter functions allowing a simple and economical power system solution for office automation, consumer, and industrial products. These devices are designed to operate directly from a rectified AC line source. In flyback converter applications they are capable of providing an output power that ranges from 6.0 W to 40 W with a fixed AC input of 100 V, 115 V, or 230 V, and 3.0 W to 20 W with a variable AC input that ranges from 85 V to 265 V.
These devices are available in economical 8−pin dual−in−line and 4−pin SOT−223 packages.

FEATUREs
• Startup Circuit Eliminates the Need for Transformer Auxiliary Bias Winding
• Optional Auxiliary Bias Winding Override for Lowest Standby Power Applications
• Converter Output Overload and Open Loop Protection
• Auto Restart Fault Protection
• IC Thermal Fault Protection
• Unique, Dual Edge, Gated Oscillator Configuration for Extremely Fast Loop Response
• Oscillator Frequency Dithering with Controlled Slew Rate Driver for Reduced EMI
• Low Power Consumption Allowing European Blue Angel Compliance
• On−Chip 700 V Power Switch Circuit and Active Startup Circuit
• Rectified AC Line Source Operation from 85 V to 265 V
• Input Undervoltage Lockout with Hysteresis
• Oscillator Frequency Options of 44 kHz, 100 kHz, 136 kHz
• Pb−Free Packages are Available

Typical Applications
• AC−DC Converters
• Wall Adapters
• Portable Electronic Chargers
• Low Power Standby and Keep−Alive Supplies