NCP1379: Controller, Quasi-Resonant, Current Mode

The NCP1379 is a high performance device aimed at powering quasi-resonant converters. Capitalizing on a proprietary valley lockout system, the controller shifts gears and reduces the switching frequency as the power loading becomes lighter. This results in a stable operation despite switching events always triggering in the drain-source valley. This system works down to the 4th valley and toggles to a variable frequency mode beyond, ensuring an excellent standby power performance. To improve the safety in the overload situations, the controller includes an Over Power Protection (OPP) circuit which clamps the delivered power at high-line. Safety-wise, a fixed internal timer relies on the feedback voltage to detect a fault. Once the timer elapses, the controller stops and enters auto-recovery mode, ensuring a low duty-cycle burst operation. Particularly well suited for TV power supply applications, the controller features a low startup voltage allowing use of an auxiliary supply to power the device.

Features
  • Quasi-resonant peak current mode control operation
  • Valley switching operation with valley lockout
  • Frequency foldback at light load
  • Adjustable overpower protection
  • Auto-recovery output short circuit protection
  • Fixed internal 80 ms timer for short circuit protection
  • VCC range operation up to 28 V
Benefits
  • High efficiency operation
  • Provides for noise-immune operation
  • Improves light load efficiency
Applications
  • Auxiliary power supplies (flat TV, appliances)
End Products
  • Power AC-DC converters for adapters, TVs and set top boxes
Design & Development Tools (1)
Document TitleDocument ID/SizeRevisionRevision Date
NCP1379, NCP1380 Design WorksheetNCP1379 NCP1380 DWS.XLS (272.0kB)1
Data Sheets (1)
Document TitleDocument ID/SizeRevisionRevision Date
Quasi-Resonant Current Mode ControllerNCP1379/D (308.0kB)2
Package Drawings (1)
Document TitleDocument ID/SizeRevision
SOIC-8 Narrow Body751-07 (62.6kB)AK
Order Information
ProductStatusCompliancePackageMSL*ContainerBudgetary Price/Unit
NCP1379DR2GActivePb-free Halide freeSOIC-8751-071Tape and Reel2500$0.35
Specifications
ProductTopologyControl Modefsw Typ (kHz)Stand-by ModeUVLO (V)Short Circuit ProtectionLatchSoft StartVCC Max (V)Drive Cap. (mA)
NCP1379DR2GFlybackCurrent ModeVariableYes9YesYesYes28500 / 800
Quasi-Resonant Current Mode Controller (308.0kB) NCP1379
NCP1379, NCP1380 Design Worksheet NCP1380
SOIC-8 Narrow Body CM1216
NCP1379