NCP1244: Controller, Fixed Frequency, Current Mode, for Flyback Converters

The NCP1244 is a new fixed-frequency current-mode controller featuring Dynamic Self-Supply. This function greatly simplifies the design of the auxiliary supply and the Vcc capacitor by activating the internal startup current source to supply the controller during start-up, transients, latch, stand-by etc. This device contains a special HV dtector which detects the application unplug from the AC input line and triggers the X2 discharge current. It features a timer-based fault detection that ensures the detection of overload and an adjustable 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 achieveing very low standby power consumption. Internal frequency jittering, ramp compensation, and a versatile latch input make this controller an excellent candidate for the robust power supply designs. A dedicated OFF mode allows to reach the extremely low no load input power consumption via sleeping whole device and thus minimze 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 (Option A) or Auto-Recovery (Option B) operation
  • High voltage current source with Dynamic Self Supply (DSS)
  • Internal Frequency Jittering
  • Adjustable overpower protection
  • Dedicated latch off input
  • Integrated X2 capacitor discharge
  • Power saving off mode when used with NCP4353 or NCP4354
Benefits
  • Maximizes efficiency in light load and standby conditions
  • Protection against overcurrent or short circuit conditions
  • Provides fast, loss-less startup
  • Softer EMI signature
  • Compensates peak current for changing line input voltage
  • Simplifies protection for fault conditions like overtemperature or overvoltage
  • Eliminates the X2 capacitor discharge resistors and their associated parasitic consumption
  • Allows the power supply to achieve extremely low no load power consumption
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
Package Drawings (1)
Document TitleDocument ID/SizeRevision
SOIC 7 CASE OUTLINE751U (62.0kB)E
Data Sheets (1)
Document TitleDocument ID/SizeRevisionRevision Date
Fixed Frequency Current Mode Controller for Flyback ConvertersNCP1244/D (1381kB)1
Order Information
ProductStatusCompliancePackageMSL*ContainerBudgetary Price/Unit
NCP1244AD065R2GActivePb-free Halide freeSOIC-7751U1Tape and Reel2500$0.35
NCP1244AD100R2GActivePb-free Halide freeSOIC-7751U1Tape and Reel2500$0.35
NCP1244BD065R2GActivePb-free Halide freeSOIC-7751U1Tape and Reel2500$0.4667
NCP1244BD100R2GActivePb-free Halide freeSOIC-7751U1Tape and Reel2500$0.35
Specifications
ProductTopologyControl Modefsw Typ (kHz)Stand-by ModeUVLO (V)Short Circuit ProtectionLatchSoft StartVCC Max (V)Drive Cap. (mA)
NCP1244AD065R2GFlybackCurrent Mode65Yes8.9YesYesYes28500 / 800
NCP1244AD100R2GFlybackCurrent Mode100Yes8.9YesYesYes28500 / 800
NCP1244BD065R2GFlybackCurrent Mode65Yes8.9YesYesYes28500 / 800
NCP1244BD100R2GFlybackCurrent Mode100Yes8.9YesYesYes28500 / 800
Fixed Frequency Current Mode Controller for Flyback Converters (1381kB) NCP1244
Design Approach to Light-Load Effective Power Supply Utilizing the NCP1244/46 PWM Controllers NCP1246
SOIC 7 CASE OUTLINE NCL30060
NCP1244