NCP1077A: Enhanced Off line Switcher for Robust and Highly Efficient Power Supplies

The NCP1077A & NCP1077B products integrate a fixed frequency current mode controller with a 700 V MOSFET. Available in a two different pin out of the very common PDIP 7 package, it offers a high level of integration, including soft start, frequency jittering, short circuit protection, skip cycle, a maximum peak current set point, ramp compensation, and a dynamic self supply (DSS, eliminating the need for an auxiliary winding).Unlike other monolithic solutions, the NCP1077A & NCP1077B is quiet by nature: during nominal load operation, the part switches at one of the available frequencies (65 or 100 kHz). When the output power demand diminishes, the IC automatically enters frequency foldback mode and provides excellent efficiency at light loads. When the power demand reduces further, it enters into a skip mode to reduce the standby consumption down to a no load condition.Protection features include: a timer to detect an overload or a short circuit event, Over voltage Protection with auto recovery. Ac input line voltage detection prevents lethal runaway in low input voltage conditions (Brown-out) as well as too high an input line (Ac line Over voltage Protection). This also allows an Over power Protection to compensate all internal delays in high input voltage conditions and optimize the maximum output current capability.For improved standby performance, the connection of an auxiliary winding stops the DSS operation and helps to reduce input power consumption below 50 mW at high line.

Features
  • Integrated 700 V MOSFET with RDS(on) of 4.7 Ω
  • Current-Mode Fixed Frequency Operation (65 & 100 kHz) - 130 kHz for B version only
  • Peak Current: NCP1076A/B = 650mA and NCP1077A/B = 800 mA
  • Skip-Cycle Operation at Low Peak Current
  • Dynamic Self-Supply (DSS)
  • Auto-Recovery Output Short Circuit Protection with Timer-Based Detection
  • Frequency Foldback Operation
  • 300 µA No Load Power Consumption
  • Frequency Jittering (including during frequency foldback mode)
  • Adjustable Brown-out Protection and OVP
  • Over Power Protection
  • 2nd Level Current Protection
Benefits
  • Up to 30W output SMPS design capability
  • Ability to scale for efficiency or size
  • Adjust output current protection based on output power demand
  • Eliminate acoustic noise
  • Eliminate Aux winding
  • Provides more robust protection without worrying about the coupling of the aux winding
  • Improved efficiency at light load / Improved EMI over the entire load
  • <50mW no Load Power Consumption
  • Better EMI Signature Over the Entire Operating Range
  • Enhanced Protection Against too Low or too High Input Voltage
  • Higher Protection of the load in wide Mains Conditions
  • Protection in case of secondary diode short
Applications
  • Auxiliary & Standby Power Supply
  • Major Home Appliances power supplies
  • Low to medium Power Chargers & Adapters
End Products
  • White Goods
  • E-Meters
  • Industrial
  • Consumer Equipment Power Supply
Design & Development Tools (1)
Document TitleDocument ID/SizeRevisionRevision Date
Flyback Transformer Design ToolFLYBACK TRANSFORMER DESIGN TOOL (21.0kB)0
Data Sheets (1)
Document TitleDocument ID/SizeRevisionRevision Date
Enhanced Off-line Switcher for Robust and Highly Efficient Power SuppliesNCP1076A/D (432kB)P4Jan, 2017
Package Drawings (2)
Document TitleDocument ID/SizeRevision
PDIP-7 (PDIP-8 LESS PIN 6)626A-01 (34.2kB)C
PDIP8 Less Pin 3626AS (34.1kB)O
Order Information
ProductStatusCompliancePackageMSL*ContainerBudgetary Price/Unit
NCP1077AAP065GActivePb-free Halide freePDIP-7626A-01NATube50$0.5333
NCP1077AAP100GActivePb-free Halide freePDIP-7626A-01NATube50$0.5333
NCP1077BAP065GActivePb-free Halide freePDIP8 Less Pin 3626ASNATube50$0.5333
NCP1077BAP100GActivePb-free Halide freePDIP8 Less Pin 3626ASNATube50$0.5333
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
NCP1077AAP065GCurrent Mode65YesYes4.7700800Yes9.26.5YesYesYesNo
NCP1077AAP100GCurrent Mode100YesYes4.7700800Yes9.26.5YesYesYesNo
NCP1077BAP065GCurrent Mode65YesYes4.7700800Yes9.26.5YesYesYesNo
NCP1077BAP100GCurrent Mode100YesYes4.7700800Yes9.26.5YesYesYesNo
Enhanced Off-line Switcher for Robust and Highly Efficient Power Supplies (434kB) NCP1079A
Flyback Transformer Design Tool NCP1129
PDIP-7 (PDIP-8 LESS PIN 6) NCP1077
PDIP8 Less Pin 3 NCP1079A