NCP1937A1DR2G
结合功率因数校正和准谐振的反激式电流模式控制器
This combination IC integrates power factor correction PFC and quasi-resonant flyback functionality necessary to implement a compact and highly efficient Switched Mode Power Supply for an adapter application.The PFC stage exhibits near-unity power factor while operating in a Critical Conduction Mode CrM with a maximum frequency clamp. The circuit incorporates all the features necessary for building a robust and compact PFC stage while minimizing the number of external components.The quasi-resonant current-mode flyback stage features a proprietary valley-lockout circuitry, ensuring stable valley switching. This system works down to the 4th valley and toggles to a frequency foldback mode with a minimum frequency clamp beyond the 4th valley to eliminate audible noise. Skip mode operation allows excellent efficiency in light load conditions while consuming very low standby power consumption.
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- <10mW No Load Standby Performance
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- Lowest no load performance
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- High Voltage Startup Circuit and Active Input Filter Capacitor Discharge Circuitry
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- Eliminates the need for an external HV startup circuit and X2 resistors.
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- High Voltage Line Voltage Detector
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- Optimize performance based on 110 v or 220 V ac mains
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- Integrated High Voltage Switch Disconnects PFC Feedback Resistor Divider
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- Reduces no load standby power
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- Fault Input for Severe Fault Conditions
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- Enhanced protection capability
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- Bi-Level Line-Dependent Output Voltage
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- Optimized system with different input voltages
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- Boost Diode Short-Circuit Protection
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- Enhanced protection features
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- Adjustable PFC Disable Threshold Based on Output Power
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- Optimized system to improve efficiency
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- Frequency Foldback with Minimum Frequency Clamp
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- Enhanced efficiency at light and no load
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- Minimum Frequency Clamp
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- Eliminates audible noise
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- Valley Switching Operation with Valley-Lockout
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- Noise free operation
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- **PFC******
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- **QR Flyback Controller******
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