NCP81178: Secondary Synchronous Rectifier Driver for Forward Converters

The NCP81178 is a secondary-side synchronous rectifier driver designed for isolated power converters, especially actively clamped forward or flyback, and asymmetric half bridge converters. The NCP81178 drives two N-channel MOSFETs on the secondary side in a complementary manner. It accepts a PWM signal that can be derived from the secondary winding or an auxiliary winding on the main power transformer. It can also take a PWM from the primary side controller through a pulse transformer or other isolator.

Features
  • N-channel synchronous rectifier MOSFET driver
  • Primary shutdown detection
  • Internally generated PWM threshold voltage with external programmability
  • 4.5A/3.8A sink and 3A source capability
  • 3mm by 3mm DFN package
Benefits
  • Drives N-channel MOSFETs to improve efficiency for high power isolated solution
  • Protection against overvoltage
  • Design flexibility
  • Strong drivers allows fast turn on/off characteristics
  • Small size reduces board space
Applications
  • Isolated DC/DC power
  • servers silver box supplies
  • 48V server, telecom and datacom
End Products
  • servers
  • datacom
  • isolated bricks
Data Sheets (1)
Document TitleDocument ID/SizeRevisionRevision Date
Secondary Synchronous Rectifier Driver for Forward ConvertersNCP81178/D (187kB)4Dec, 2016
Package Drawings (1)
Document TitleDocument ID/SizeRevision
DFN10, 3x3, 0.5P506CL (55.8kB)O
Order Information
ProductStatusCompliancePackageMSL*ContainerBudgetary Price/Unit
NCP81178MNTXGActivePb-free Halide freeDFN-10506CL1Tape and Reel3000Contact BDTIC
Specifications
ProductVCC Max (V)Vref Typ (V)ICC Max (A)TA Min (°C)TA Max (°C)
NCP81178MNTXG141.25-40125
Secondary Synchronous Rectifier Driver for Forward Converters (187kB) NCP81178
DFN10, 3x3, 0.5P NCP81178