NCP1249C Datasheet, PDF (1/33 Pages) ON Semiconductor – High-Voltage CurrentMode PWM Controller Featuring Peak Power Excursion

NCP1249C, NCP1249D
High-Voltage Current­Mode
PWM Controller Featuring
Peak Power Excursion and
Self-Relaxing Off Mode
The NCP1249 is a highly integrated high−voltage PWM controller
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capable of delivering a rugged and high performance offline power
supply with extremely low no−load consumption. With a supply range
MARKING DIAGRAM
up to 30 V, the controller hosts a jittered 65 kHz switching circuitry
operated in peak current mode control. When the power on the
secondary side starts to decrease, the controller 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 freezing
the peak current setpoint.
To help build rugged converters, the controller features several key
9
1
SOIC−9 NB
D SUFFIX
CASE 751BP
9
NCP1249x65
ALYW
G
1
protective features: a internal brown−out, a non−dissipative Over
Power Protection for a constant maximum output current regardless of
the input voltage and two latched over voltage protection inputs −
either through a dedicated pin or via the VCC input.
The controller architecture is arranged to authorize a transient peak
XXXXX = Specific Device Code
A
= Assembly Location
L
= Wafer Lot
Y
= Year
W
= Work Week
G
= Pb−Free Package
power excursion when the peak current hits the limit. At this point, the
switching frequency is increased from 65 kHz to 130 kHz until the
PIN CONNECTIONS
peak requirement disappears. The timer duration is then modulated as
the converter crosses a peak power excursion mode (long) or
undergoes a short circuit (short).
Features
• High−Voltage Current Source for Lossless Start−up Sequence
X2
FB/REM
OPP/Latch
Timer
1
(Top View)
HV
V_CC
DRV
GND
• Automatic and Lossless X2 Capacitors Discharge Function
• 65 kHz Fixed−Frequency Current−Mode Control Operation with
130 kHz Excursion
• Internal and Adjustable Over Power Protection (OPP)
• Up to 30 V VCC Maximum Rating
Circuit
• Internal Brown−Out Protection Circuit
• Frequency Foldback Down to 26 kHz and Skip−Cycle
• +300 mA/ −500 mA Source/Sink Drive Capability
• Extremely Low No−Load Standby Power via
Controlled Self−Relaxing Off Mode
in Light Load Conditions
• Adjustable Ramp Compensation
• Option for Auto−Recovery or Latched Short−Circuit
Protection
• Internally Fixed 4 ms Soft−Start
• Internal Thermal Shutdown with Hysteresis
• Adjustable Timer-Based Auto−Recovery
• These are Pb−Free Devices
Overload/Short−Circuit Protection
• 100% to 25% Timer Reduction from Overload to
Short−Circuit Fault
• Frequency Jittering in Normal and Frequency Foldback
Modes
Typical Applications
• Converters Requiring Peak−power Capability such as
Printers Power Supplies, ac−dc Adapters for Game
Stations
• Latched OVP Input for Improved Robustness and
Latched OVP on VCC
ORDERING INFORMATION
See detailed ordering and shipping information on page 2 of
this data sheet.
© Semiconductor Components Industries, LLC, 2013
1
September, 2013 − Rev. 0
Publication Order Number:
NCP1249C/D