NCP1341: High-Voltage, Quasi-Resonant, Controller Featuring Valley Lock-Out Switching with Power Excursion Mode (PEM)

The NCP1341 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 NCP1341 can enable no−load power consumption below 30 mW. The quasi−resonant current−mode flyback stage features a proprietary valley−lockout circuitry, ensuring stable valley switching. This system works down to the 6th valley and transitions to a frequency foldback mode to reduce switching losses. As the load decreases further, the NCP1341 enters quiet−skip mode to manage the power delivery. The NCP1341 integrates power excursion mode (PEM) to minimize transformer size in designs requiring high transient load capability. If transient load capability is not desired, the NCP1340 offers the same performance and features without PEM. To help ensure converter ruggedness, the NCP1341 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 over voltage and NTC−ready over-temperature protection through a dedicated pin, and line removal detection to safely discharge the X2 capacitors when the line is removed.

Features
  • QR Frequency Jittering
  • New Quiet-Skip™ Technology
  • Integrated HV Startup with Brownout Protection
  • Valley Switching Operation with Valley Lockout
  • Integrated X2 Capacitor Discharge Capability
  • NTC Compatible Fault Pin
  • High Drive Capability: -500 mA / +800 mA
  • Latch input for OVP and OTP implementations
  • Power Excursion Mode (PEM)
Benefits
  • Reduces EMI Signature
  • Ensures Operation Outside Audible Range
  • Provides an efficient power-on source and protects agaisnts drops in input mains voltage
  • Maximizing the efficiency over the entire power range
  • Eliminates the need for a X2 resistors
  • Extra protection against high temperature or other fault conditions
  • Enables faster switching of primary-side MOSFET
  • Simple implementation of required protection functions
  • Minimize transformer size in designs requiring high transient load capability
Applications
  • Medium or High Power AC-DC Adapters
  • Ultra High Density AC-DC Adapters
  • Computer Power Supplies
  • Phone and Tablet Adapters
End Products
  • Notebook Adpaters
  • Flat TV SMPS
  • Computer Power Supplies
  • Phone and Tablet Adapters
Data Sheets (1)
Document TitleDocument ID/SizeRevisionRevision Date
High-Voltage, Quasi-Resonant Controller featuring Valley Lock-Out SwitchingNCP1341/D (1150kB)0
Evaluation Board Documents (4)
Document TitleDocument ID/SizeRevisionRevision Date
NCP1341GEVB Bill of Materials (ROHS Compliant)NCP1341GEVB_BOM_ROHS (49kB)0
NCP1341GEVB Gerber Layout Files (Zip Format)NCP1341GEVB_GERBER (123kB)0
NCP1341GEVB SchematicNCP1341GEVB_SCHEMATIC (172kB)0
NCP1341GEVB Test ProcedureNCP1341GEVB_TEST_PROCEDURE (116kB)0
Package Drawings (2)
Document TitleDocument ID/SizeRevision
SOIC-8 Narrow Body751-07 (62.6kB)AK
SOIC9 NB751BP (54.4kB)A
Evaluation/Development Tool Information
ProductStatusComplianceShort Description
NCP1341GEVBActivePb-freeHigh-Voltage, Quasi-Resonant Controller Featuring Valley Lock-Out Switching Evaluation Board.
Order Information
ProductStatusCompliancePackageMSL*ContainerBudgetary Price/Unit
NCP1341B1D1R2GActivePb-free Halide freeSOIC9 NB751BP1Tape and Reel2500$0.4533
NCP1341B1DR2GActivePb-free Halide freeSOIC-8751-071Tape and Reel2500$0.4267
Specifications
ProductTopologyControl Modefsw Typ (kHz)Stand-by ModeUVLO (V)Short Circuit ProtectionLatchSoft StartVCC Max (V)Drive Cap. (mA)
NCP1341B1D1R2GFlybackCurrent ModeVariableYes9YesYesYes30500 / 800
NCP1341B1DR2GFlybackCurrent ModeVariableYes9YesYesYes30500 / 800
High-Voltage, Quasi-Resonant Controller featuring Valley Lock-Out Switching (1150kB) NCP1341
NCP1341GEVB BOM ROHS - 49 KB NCP1341GEVB
NCP1341GEVB GERBER - 123 KB NCP1341GEVB
NCP1341GEVB SCHEMATIC - 172 KB NCP1341GEVB
NCP1341GEVB TEST PROCEDURE - 116 KB NCP1341GEVB
SOIC9 NB NCP1249
SOIC-8 Narrow Body CM1216