for Medium Power Offline
SMPS Featuring Low
The NCP1027 offers a new solution targeting output power levels
from a few watts up to 15 W in a universal mains flyback application.
Our proprietary high−voltage technology lets us include a power
MOSFET together with a startup current source, all directly
connected to the bulk capacitor. To prevent lethal runaway in low
input voltage conditions, an adjustable brown−out circuitry blocks
the activity until sufficient input level is reached.
Current−mode operation together with an adjustable ramp
compensation offers superior performance in universal mains
applications. Furthermore, an Over Power Protection pin brings the
ability to precisely compensate all internal delays in high input voltage
conditions and optimize the maximum output current capability.
Protection wise, a timer detects an overload or a short−circuit and
stops all operations, ensuring a safe auto−recovery, low duty cycle burst
operation. An integrated, auto−recovery, Overvoltage Protection
permanently monitors the VCC level and temporarily shuts down the
driving pulses in case of an unexpected feedback loop runaway.
Finally, a great RDS(on) figure makes the circuit an excellent choice
for standby/auxiliary offline power supplies or applications requiring
higher output power levels.
• Built−in 700 V MOSFET with Typical RDS(on) of 5.8 W, TJ = 25°C
• Current−Mode Fixed Frequency Operation: 65 kHz and 100 kHz
• Fixed Peak Current of 800 mA
• Skip−Cycle Operation at Low Peak Currents
• Internal Current Source for Clean and Lossless Startup Sequence
• Auto−Recovery Output Short Circuit Protection with Timer−Based
• Auto−Recovery Overvoltage Protection with Auxiliary Winding
• Programmable Brown−Out Input for Low Input Voltage Detection
• Programmable Over Power Protection
• Input to Permanently Latchoff the Part
• Internal Frequency Jittering for Improved EMI Signature
• Extended Duty Cycle Operation to 80% Typical
• No−Load Input Standby Power of 85 mW @ 265 Vac
• 500 mW Loaded, Input Power of 715 mW @ 230 Vac
• These are Pb−Free Devices
• Medium Power AC−DC Adapters for Chargers
• Auxiliary/Standby Power Supplies for ATX and TVS Power Supplies
NCP1027 − 5.8 W
*Typical values, open−frame, 65 kHz version, RqJA < 75°C/W, TA = 50°C.
XXX = 65 or 100
A = Assembly Location
WL = Wafer Lot
YY = Year
WW = Work Week
G = Pb−Free Package
PDIP−8 50 Units / Rail
PDIP−8 50 Units / Rail
*For additional information on our Pb−Free strategy
and soldering details, please download the
ON Semiconductor Soldering and Mounting
Techniques Reference Manual, SOLDERRM/D.
© Semiconductor Components Industries, LLC, 2006
December, 2006 − Rev. 3
Publication Order Number: