NCP1246: Controller, Fixed Frequency, Current Mode, for Flyback Converters

The NCP1246 is a new fixed-frequency current-mode controller featuring Dynamic Self-Supply. This function greatly simplifies the design of the auxiiary supply and the Vcc capacitor by activating the internal startup current source to supply the controller during start-up, transients, latch, stnad-by etc. This device contains a special HV detector which detects the application unplug from the AC input line and triggers the X2 discharge current. The HV structure also includes brown-out detection circuitry. The NCP1246 features a timer-based fault detection that ensures the detection of overload and an adjustable power compensation to help keep the maximum power independent of the input voltage. Due to frequency foldback, the controller exhibits excellent efficiency in light load condition while still achieving very low standby power consumption. Internal frequency jittering, ramp compensation, and a versatile latch input make this controller an excellent candidate for robust power supply designs. A dedicated off mode allows the SMPS to reach extremely low no load input power consumption when combinded with secondary side contoller NCP4353 or NCP4354. When used together, the SMPS is capable of achieving <10 mW no load input power consumption. The secondary side contoller signals the NCP1246 to enter a sleep mode, minimizing the power consumption of the control circuitry. This product is IEC60950 compliant. Please see the test report and certification in the Conformance report section below.

Features
  • Frequency foldback and skip mode
  • Timer-based overload protection with latched (A version) or auto-recovery (B version) operation
  • High-voltage startup with dynamic self supply
  • Integrated brown-out detection
  • Frequency Modulation
  • Adjustable overpower protection
  • Latch off input
Benefits
  • Optimized efficiency across the entire load range
  • Protection against overcurrent and short circuit
  • Simplifies the design of the auxiliary supply
  • Protects against any drops in line voltage
  • Softened EMI signature
  • Automatically adjusts the current limit depending on the line input voltage (high line or low line)
  • Protection against faults
Applications
  • AC-DC Adapters
  • LCD TV power supplies
End Products
  • Notebook Computers
Application Notes (1)
Document TitleDocument ID/SizeRevisionRevision Date
Design Approach to Light-Load Effective Power Supply Utilizing the NCP1244/46 PWM ControllersAND9170/D (1697kB)0Jul, 2014
Data Sheets (1)
Document TitleDocument ID/SizeRevisionRevision Date
Fixed Frequency Current Mode Controller for Flyback ConvertersNCP1246/D (1260kB)6
Package Drawings (1)
Document TitleDocument ID/SizeRevision
SOIC 7 CASE OUTLINE751U (62.0kB)E
Evaluation Board Documents (5)
Document TitleDocument ID/SizeRevisionRevision Date
65 W Off-Line Adapter Featuring Very Low No-Load Power Consumption Evaluation Board User's ManualEVBUM2138/D (746.0kB)0
NCP4354AADAPGEVB Bill of Materials ROHS CompliantNCP4354AADAPGEVB_BOM_ROHS.PDF (279.0kB)0
NCP4354AADAPGEVB Gerber Layout Files (Zip Format)NCP4354AADAPGEVB_GERBER.ZIP (2900kB)1
NCP4354AADAPGEVB SchematicNCP4354AADAPGEVB_SCHEMATIC.PDF (94.0kB)0
NCP4354AADAPGEVB Test ProcedureNCP4354AADAPGEVB_TEST_PROCEDURE.PDF (83.0kB)0
Evaluation/Development Tool Information
ProductStatusComplianceShort Description
NCP4354AADAPGEVBActivePb-free65 W Adapter Off-Mode Controller Demonstration Evaluation Board
Order Information
ProductStatusCompliancePackageMSL*ContainerBudgetary Price/Unit
NCP1246AD065R2GActivePb-free Halide freeSOIC-7751U1Tape and Reel2500$0.5
NCP1246AD100R2GActivePb-free Halide freeSOIC-7751U1Tape and Reel2500$0.5
NCP1246ALD065R2GActivePb-free Halide freeSOIC-7751U1Tape and Reel2500$0.5
NCP1246ALD100R2GActivePb-free Halide freeSOIC-7751U1Tape and Reel2500$0.5
NCP1246BD065R2GActivePb-free Halide freeSOIC-7751U1Tape and Reel2500$0.5
NCP1246BD100R2GActivePb-free Halide freeSOIC-7751U1Tape and Reel2500$0.5
NCP1246BLD065R2GActivePb-free Halide freeSOIC-7751U1Tape and Reel2500$0.5
NCP1246BLD100R2GActivePb-free Halide freeSOIC-7751U1Tape and Reel2500$0.5
Specifications
ProductTopologyControl Modefsw Typ (kHz)Stand-by ModeUVLO (V)Short Circuit ProtectionLatchSoft StartVCC Max (V)Drive Cap. (mA)
NCP1246AD065R2GFlybackCurrent Mode65Yes8.9YesYesYes28500 / 800
NCP1246AD100R2GFlybackCurrent Mode100Yes8.9YesYesYes28500 / 800
NCP1246ALD065R2GFlybackCurrent Mode65Yes8.9YesYesYes28500 / 800
NCP1246ALD100R2GFlybackCurrent Mode100Yes8.9YesYesYes28500 / 800
NCP1246BD065R2GFlybackCurrent Mode65Yes8.9YesYesYes28500 / 800
NCP1246BD100R2GFlybackCurrent Mode100Yes8.9YesYesYes28500 / 800
NCP1246BLD065R2GFlybackCurrent Mode65Yes8.9YesYesYes28500 / 800
NCP1246BLD100R2GFlybackCurrent Mode100Yes8.9YesYesYes28500 / 800
Fixed Frequency Current Mode Controller for Flyback Converters (1260kB) NCP1246
Design Approach to Light-Load Effective Power Supply Utilizing the NCP1244/46 PWM Controllers NCP1246
SOIC 7 CASE OUTLINE NCL30060
NCP1246