onsemi NCP1342ENDCEAD1R2G

The NCP1342 is a highly integrated quasi−resonant flyback controller suitable for designing high−performance off−line power converters. With an integrated active X2 capacitor discharge feature, the NCP1342 can enable no−load power consumption below 30 mW.

The NCP1342 features a proprietary valley−lockout circuitry, ensuring stable valley switching. This system works down to the 6th valley and transitions to frequency foldback mode to reduce switching losses. As the load decreases further, the NCP1342 enters quiet−skip mode to manage the power delivery while minimizing acoustic noise.

To ensure light load performance with high frequency designs, the NCP1342 incorporates Rapid Frequency Foldback with Minimum Peak Current Modulation to reduce the switching frequency quickly. To help ensure converter ruggedness, the NCP1342 implements several key protective features such as internal brownout detection, a non−dissipative Over Power Protection (OPP) for constant maximum output power regardless of input voltage, a latched overvoltage and NTC−ready overtemperature protection through a dedicated pin, and line removal detection to safely discharge the X2 capacitors when the ac line is removed.

The NCP1342 implements a quasi−resonant flyback converter utilizing current−mode architecture where the switch−off event is dictated by the peak current. This IC is an ideal candidate where low parts count and cost effectiveness are the key parameters, particularly in ac−dc adapters, open−frame power supplies, etc. The NCP1342 incorporates all the necessary components normally needed in modern power supply designs, bringing several enhancements such as non−dissipative overpower protection (OPP), brownout protection, and frequency.

• Integrated High−Voltage Startup Circuit with Brownout Detection
• Integrated X2 Capacitor Discharge Capability
• Wide VCC Range from 9 V to 28 V
• 28 V VCC Overvoltage Protection
• Abnormal Overcurrent Fault Protection for Winding Short Circuit or Saturation Detection
• Internal Temperature Shutdown
• Valley Switching Operation with Valley−Lockout for Noise−Free Operation
• Frequency Foldback with 25 kHz Minimum Frequency Clamp for Increased Efficiency at Light Loads
• Rapid Frequency Foldback for Fast Reduction of Switching Frequency at Light Loads
• Skip Mode with Quiet−Skip Technology for Highest Performance During Light Loads
• Minimized Current Consumption for No Load Power Below 30 mW
• Frequency Jittering for Reduced EMI Signature
• Latching or Auto−Recovery Timer−Based Overload Protection
• Adjustable Overpower Protection (OPP)
• Adjustable Maximum Frequency Clamp
• Fault Pin for Severe Fault Conditions, NTC Compatible for OTP
• 4 ms Soft−Start Timer