NCP1351: Controller, Variable Off-Time Current Mode, with Short Circuit Protection

The NCP1351 is a current mode controller targeting low power off line flyback Switched Mode Power Supplies (SMPS) where cost is of utmost importance. Based on a fixed peak current technique (quasi fixed TON), the controller decreases its switching frequency as the load becomes lighter. As a result, a power supply using the NCP1351 naturally offers excellent no load power consumption, while optimizing the efficiency in other loading conditions. When the frequency decreases, the peak current is gradually reduced down to approximately 30% of the maximum peak current to prevent transformer mechanical resonance. The risk of acoustic noise is thus greatly diminished while keeping good standby power performance.An externally adjustable timer permanently monitors the feedback activity and protects the supply in presence of a short circuit or an overload. Once the timer elapses, NCP1351 stops switching and stays latched for version A, and tries to restart for Version B.The internal structure features an optimized arrangement which allows one of the lowest available startup current, a fundamental parameter when designing low standby power supplies. The negative current sensing technique minimizes the impact of the switching noise on the controller operation and offers the user to select the maximum peak voltage across his current sense resistor. Its power dissipation can thus be application optimized.Finally, the bulk input ripple ensures a natural frequency smearing which smooths the EMI signature.

Features
  • Quasi fixed TON, Variable TOFF Current Mode Control
  • Frequency foldback with Peak Current Compression
  • Short circuit protection (latched A version or auto restart B version)
  • Primary or secondary side regulation
  • Dedicated Latch Input for OTP, OVP
  • Low start-up current
  • Natural frequency jittering
  • Negative current sensing with programmable current sense resistor
Benefits
  • Natural frequency foldback
  • Noise free & improved efficiency in light load
  • Independent of the auxiliary Winding
Applications
  • Auxiliary Power Supply
  • Off-line battery chargers
End Products
  • Printers
  • Adapters
Design & Development Tools (1)
Document TitleDocument ID/SizeRevisionRevision Date
NCP1351 Design WorksheetNCP1351 DWS.XLS (80.0kB)1.3
Data Sheets (1)
Document TitleDocument ID/SizeRevisionRevision Date
Variable Off Time PWM ControllerNCP1351/D (526.0kB)3
Package Drawings (2)
Document TitleDocument ID/SizeRevision
8 LEAD PDIP626-05 (35.0kB)P
SOIC-8 Narrow Body751-07 (62.6kB)AK
Application Notes (6)
Document TitleDocument ID/SizeRevisionRevision Date
Implementing an LCD TV Power Supply with the NCP1392B, NCP1606 and NCP1351BAND8344/D (4676kB)2May, 2015
NCP1351 Evaluation Board Printer Power SupplyAND8278/D (549.0kB)0
NCP1351 Evaluation Board, 19 V - 3 A AdaptorAND8263/D (260.0kB)1
NCP1351 Evaluation Board, a 12 V / 2 A Full DCMAND8288/D (328.0kB)0
NCP1351 Modeling Using the PWM Switch TechniqueAND8280/D (184.0kB)0
Stability Analysis in Multiple Loop SystemsAND8327/D (213.0kB)0
Evaluation Board Documents (15)
Document TitleDocument ID/SizeRevisionRevision Date
NCP1351ADAPGEVB Bill of Material ROHS CompliantNCP1351ADAPGEVB_BOM_ROHS.PDF (1239.0kB)0
NCP1351ADAPGEVB Gerber Layout Files (Zip Format)NCP1351ADAPGEVB_GERBER.ZIP (114.0kB)0
NCP1351ADAPGEVB ManualEVBUM2147/D (352.0kB)2
NCP1351ADAPGEVB SchematicNCP1351ADAPGEVB_SCHEMATIC.PDF (278.0kB)0
NCP1351ADAPGEVB Test ProcedureNCP1351ADAPGEVB_TEST_PROCEDURE.PDF (173.0kB)0
NCP1351LEDGEVB Bill of Materials ROHS CompliantNCP1351LEDGEVB_BOM_ROHS.PDF (140.0kB)0
NCP1351LEDGEVB Gerber Layout Files (Zip Format)NCP1351LEDGEVB_GERBER.ZIP (141.0kB)0
NCP1351LEDGEVB SchematicNCP1351LEDGEVB_SCHEMATIC.PDF (144.0kB)0
NCP1351LEDGEVB Test ProcedureNCP1351LEDGEVB_TEST_PROCEDURE.PDF (138.0kB)0
NCP1351PRINTGEVB Bill of Materials ROHS CompliantNCP1351PRINTGEVB_BOM_ROHS.PDF (161.0kB)0
NCP1351PRINTGEVB Gerber Layout Files (Zip Format)NCP1351PRINTGEVB_GERBER.ZIP (136.0kB)0
NCP1351PRINTGEVB ManualEVBUM2150/D (1748.0kB)0
NCP1351PRINTGEVB SchematicNCP1351PRINTGEVB_SCHEMATIC.PDF (122.0kB)0
NCP1351PRINTGEVB Test ProcedureNCP1351PRINTGEVB_TEST_PROCEDURE.PDF (196.0kB)1
Universal Input, 20 W, LED Ballast Evaluation Board User's ManualEVBUM2059/D (426.0kB)3
Simulation Models (2)
Document TitleDocument ID/SizeRevisionRevision Date
NCP1351 ISPICE ModelNCP1351 ISPICE MODEL (51.0kB)0
NCP1351 PSPICE ModelNCP1351 PSPICE MODEL (42.0kB)1
Evaluation/Development Tool Information
ProductStatusComplianceShort Description
NCP1351ADAPGEVBActivePb-free57 W Adapter Evaluation Board
NCP1351LEDGEVBActivePb-free20 W Constant Current LED Driver Evaluation Board
NCP1351PRINTGEVBActivePb-free40 W Printer Evaluation Board
Order Information
ProductStatusCompliancePackageMSL*ContainerBudgetary Price/Unit
NCP1351ADR2GActivePb-free Halide freeSOIC-8751-071Tape and Reel2500$0.32
NCP1351APGObsoletePb-free Halide freePDIP-8626-05NATube50
NCP1351BDR2GActivePb-free Halide freeSOIC-8751-071Tape and Reel2500$0.32
NCP1351BPGObsoletePb-free Halide freePDIP-8626-05NATube50
NCP1351CDR2GActivePb-free Halide freeSOIC-8751-071Tape and Reel2500$0.32
NCP1351CPGObsoletePb-free Halide freePDIP-8626-05NATube50
NCP1351DDR2GActivePb-free Halide freeSOIC-8751-071Tape and Reel2500$0.32
NCP1351DPGObsoletePb-free Halide freePDIP-8626-05NATube50
Specifications
ProductTopologyControl Modefsw Typ (kHz)Stand-by ModeUVLO (V)Short Circuit ProtectionLatchSoft StartVCC Max (V)Drive Cap. (mA)
NCP1351ADR2GFlybackCurrent ModeVariableNoYesYesYesNo28400 / 400
NCP1351BDR2GFlybackCurrent ModeVariableNoYesYesYesNo28400 / 400
NCP1351CDR2GFlybackCurrent ModeVariableNoYesYesYesNo28400 / 400
NCP1351DDR2GFlybackCurrent ModeVariableNoYesYesYesNo28400 / 400
Variable Off Time PWM Controller (526.0kB) NCP1351
NCP1351 Design Worksheet NCP1351
Implementing an LCD TV Power Supply with the NCP1392B, NCP1606 and NCP1351B NCP1607
NCP1351 Evaluation Board Printer Power Supply NCP1351
NCP1351 Evaluation Board, 19 V - 3 A Adaptor NCP1351
NCP1351 Evaluation Board, a 12 V / 2 A Full DCM NCP1351
NCP1351 Modeling Using the PWM Switch Technique NCP1351
Stability Analysis in Multiple Loop Systems NCP1055
NCP1351ADAPGEVB BOM ROHS NCP1351ADAPGEVB
NCP1351ADAPGEVB GERBER NCP1351ADAPGEVB
EVBUM2147/D - 352 NCP1351ADAPGEVB
NCP1351ADAPGEVB SCHEMATIC NCP1351ADAPGEVB
NCP1351ADAPGEVB TEST PROCEDURE NCP1351ADAPGEVB
NCP1351LEDGEVB BOM ROHS NCP1351LEDGEVB
NCP1351LEDGEVB GERBER NCP1351LEDGEVB
NCP1351LEDGEVB SCHEMATIC NCP1351LEDGEVB
NCP1351LEDGEVB TEST PROCEDURE NCP1351LEDGEVB
NCP1351PRINTGEVB BOM ROHS NCP1351PRINTGEVB
NCP1351PRINTGEVB GERBER NCP1351PRINTGEVB
EVBUM2150/D - 1748 NCP1351PRINTGEVB
NCP1351PRINTGEVB SCHEMATIC NCP1351PRINTGEVB
NCP1351PRINTGEVB TEST PROCEDURE NCP1351PRINTGEVB
EVBUM2059/D - 426 NCP1351LEDGEVB
NCP1351 ISPICE Model NCP1351
NCP1351 PSPICE Model NCP1351
SOIC-8 Narrow Body CM1216
8 LEAD PDIP NE592