NCP1129: High Voltage Switching Regulator for Offline SMPS

The NCP1129 switcher offers everything needed to build reliable and compact AC-DC switching power supplies with minimal surrounding elements. Incorporating an avalanche rated 650 V MOSFET, converters built with the NCP1129 can be safely designed for international conditions without jeopardizing the overall reliability. The NCP1129 implements peak current mode control with adjustable ramp compensation that ensures stability in Continuous Conduction Mode (CCM) operation. With an external resistor, the maximum peak current is adjustable, allowing the designer the ability to inject ramp compensation to stabilize CCM power supplies. A short circuit fault condition is independently detected from the auxiliary winding voltage resulting in improved short circuit protection with true overload detection. The Source pin provides access to the MOSFET source, allowing for overpower compensation. With a supply range up to 26 V, the switcher also provides a jittered 65 kHz or 100 kHz switching frequency operated in peak current mode control. When the power on the secondary side starts to decrease, the switcher automatically folds back its switching frequency down to a minimum level of 26 kHz. As the power further goes down, the part enters skip cycle while limiting the peak current.

Features
  • 650 V Avalanche Rated MOSFET
  • FixedFrequency 65 or 100 kHz CurrentMode Control Operation
  • Frequency Foldback Down to 26 kHz and SkipCycle in Light Load Conditions
  • Adjustable Current Limit
  • 50 ms Timer-Based Auto-Recovery Short-Circuit Protection
  • Frequency Jittering in Normal and Frequency Foldback Modes
  • Option for Auto-Recovery or Latched Short-Circuit Protection
  • Less than 100 mW Standby Power at High Line
Benefits
  • Rugged MOSFET for robust design
  • Ability to scale for efficiency or size
  • Eliminate acoustic noise and improved efficiency at light loads
  • Scale for various designs 5W~20W
  • Provides more robust protection without worrying about the coupling of the aux winding
  • Improved efficiency at light load / Improved EMI over the entire load
  • Flexible protection options
  • EPS 2.0 Compliant
Applications
  • Power Supply
End Products
  • Power supply for DVD, STB, CD-Player
  • Aux supply for TV, USB, Appliance
Design & Development Tools (2)
Document TitleDocument ID/SizeRevisionRevision Date
Flyback Current Mode Loop Compensation Design WorksheetFLYBACK DWS.XLS.ZIP (3516kB)10Dec, 2014
Flyback Transformer Design ToolFLYBACK TRANSFORMER DESIGN TOOL (21.0kB)0
Package Drawings (1)
Document TitleDocument ID/SizeRevision
PDIP-7 (PDIP-8 LESS PIN 7)626B (34.7kB)D
Data Sheets (1)
Document TitleDocument ID/SizeRevisionRevision Date
High Voltage Switcher for Offline Power SuppliesNCP1126/D (189kB)3Mar, 2015
Evaluation Board Documents (4)
Document TitleDocument ID/SizeRevisionRevision Date
NCP1129DIPGEVB Bill of Materials ROHS CompliantNCP1129DIPGEVB_BOM_ROHS.PDF (54.0kB)0
NCP1129DIPGEVB Gerber Layout Files (Zip Format)NCP1129DIPGEVB_GERBER.ZIP (105.0kB)0
NCP1129DIPGEVB SchematicNCP1129DIPGEVB_SCHEMATIC.PDF (45.0kB)0
NCP1129DIPGEVB Test ProcedureNCP1129DIPGEVB_TEST_PROCEDURE.PDF (82.0kB)0
Evaluation/Development Tool Information
ProductStatusComplianceShort Description
NCP1129DIPGEVBActivePb-free25W Offline Power Supply High Voltage Switcher Evaluation Board
Order Information
ProductStatusCompliancePackageMSL*ContainerBudgetary Price/Unit
NCP1129AP100GActivePb-free Halide freePDIP-8626BNATube50$0.56
NCP1129AP65GActivePb-free Halide freePDIP-8626BNATube50$0.56
NCP1129BP100GActivePb-free Halide freePDIP-8626BNATube50$0.56
NCP1129BP65GActivePb-free Halide freePDIP-8626BNATube50$0.56
Specifications
ProductControl Modefsw Typ (kHz)fJitter Typ (%)Stand-by ModeRDS(ON) Typ (Ω)V(BR)DSS Max (V)IPeak (mA)HV Start-up Min (V)DSS (mA)UVLOShort Circuit ProtectionOver Power CompensationBrown-outLatch
NCP1129AP100GCurrent Mode100+/-5% of FSWYes26500Yes08.8YesNoNoYes
NCP1129AP65GCurrent Mode65+/-5% of FSWYes26500Yes08.8YesNoNoYes
NCP1129BP100GCurrent Mode100+/-5% of FSWYes26500Yes08.8YesNoNoNo
NCP1129BP65GCurrent Mode65+/-5% of FSWYes26500Yes08.8YesNoNoNo
High Voltage Switcher for Offline Power Supplies (189kB) NCP1129
Flyback Current Mode Loop Compensation Design Worksheet NCP1129
Flyback Transformer Design Tool NCP1129
NCP1129DIPGEVB BOM ROHS NCP1129DIPGEVB
NCP1129DIPGEVB GERBER NCP1129DIPGEVB
NCP1129DIPGEVB SCHEMATIC NCP1129DIPGEVB
NCP1129DIPGEVB TEST PROCEDURE NCP1129DIPGEVB
PDIP-7 (PDIP-8 LESS PIN 7) NCP1129
NCP1129