NCP107xAA/BA Enhanced Offline Switcher

NCP107xAA/BA Enhanced Offline Switcher

ON Semiconductor's NCP107xAA and NCP107xBA products integrate a fixed frequency current mode controller with a 700 V MOSFET. Available in two pinout versions of the popular PDIP-7 package (a PDIP8 package with one pin omitted to ensure adequate creepage distance), they offer 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 NCP107xAA & NCP107xBA are quiet by nature: during nominal load operation, the part switches at one of the available frequencies (65, 100, and in selective cases 130 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.

Device Frequency RDS(ON) ohms IPK(mA) Package Type
NCP1075A 65,100 13.5 400 PDIP8: Pin 6 omitted
NCP1075B 65,100,130 13.5 400 PDIP8: Pin 3 omitted
NCP1076A 65,100 4.8 650 PDIP8: Pin 6 omitted
NCP1076B 65,100,130 4.8 650 PDIP8: Pin 3 omitted
NCP1077A 65,100 4.8 800 PDIP8: Pin 6 omitted
NCP1077B 65,100,130 4.8 800 PDIP8: Pin 3 omitted
NCP1079A 65,100 2.9 1050 PDIP8: Pin 6 omitted
NCP1079B 65,100,130 2.9 1050 PDIP8: Pin 3 omitted

Features Applications
  • Integrated 700 V MOSFET
  • Current-mode fixed frequency operation (65kHz and 100 kHz); 130 kHz for B version only
  • Adjust output current protection based on output power demand
  • Skip-cycle operation at low peak current
  • Dynamic self-supply (DSS)
  • Auto-recovery output short-circuit protection with timer-based detection
  • Frequency foldback operation
  • Improved efficiency at light load / improved EMI over the entire load
  • Auxiliary and standby power supplies
  • Major home appliances power supplies
  • Low to medium power chargers and adapters
  • White goods and home appliances
  • E-meters
  • Industrial auxiliary power supplies
  • Consumer equipment power supplies
Design Note:  NCP1076 / NCP1077 / NCP431 Design Note
Calculator:  Flyback Transformer Design Tool