NCP1341
High-Voltage,
Quasi-Resonant, Controller
Featuring Valley Lock-Out
Switching
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The NCP1341 is a highly integrated quasi−resonant flyback
controller suitable for designing high−performance off−line power
converters. With an integrated active X2 capacitor discharge feature,
the NCP1341 can enable no−load power consumption below 30 mW.
The NCP1341 features a proprietary valley−lockout circuitry,
8
9
1
1
th
ensuring stable valley switching. This system works down to the 6
SOIC−9 NB
D SUFFIX
CASE 751BP
SOIC−8 NB
D SUFFIX
CASE 751
valley and transitions to frequency foldback mode to reduce switching
losses. As the load decreases further, the NCP1341 enters quiet−skip
mode to manage the power delivery while minimizing acoustic noise.
The NCP1341 integrates power excursion mode (PEM) to minimize
transformer size in designs requiring high transient load capability. If
transient load capability is not desired, the NCP1340 offers the same
performance and features without PEM.
To help ensure converter ruggedness, the NCP1341 implements
several key protective features such as internal brownout detection, a
non−dissipative Over Power Protection (OPP) for constant maximum
output power regardless of input voltage, a latched overvoltage and
NTC−ready overtemperature protection through a dedicated pin, and
line removal detection to safely discharge the X2 capacitors when the
ac line is removed.
MARKING DIAGRAM
9
1341xz
ALYW
G
1
1341xz = Specific Device Code
x
z
A
L
= A or B
= 1, 2, 3 or 4
= Assembly Location
= Wafer Lot
Features
Y
W
G
= Year
= Work Week
= Pb−Free Package
• Integrated High−Voltage Startup Circuit with Brownout Detection
• Integrated X2 Capacitor Discharge Capability
• Wide V Range from 9 V to 28 V
CC
• 28 V V Overvoltage Protection
CC
PIN CONNECTIONS
• Abnormal Overcurrent Fault Protection for Winding Short Circuit or
1
Fault
HV
Saturation Detection
FMAX
FB
ZCD/OPP
CS
• Internal Temperature Shutdown
• Valley Switching Operation with Valley−Lockout for Noise−Free
Operation
VCC
DRV
GND
• Frequency Foldback with 25 kHz Minimum Frequency Clamp for
Increased Efficiency at Light Loads
1
HV
FMAX
FB
• Skip Mode with Quiet−Skip Technology for Highest Performance
During Light Loads
VCC
DRV
GND
ZCD/OPP
CS
• Minimized Current Consumption for No Load Power Below 30 mW
• Frequency Jittering for Reduced EMI Signature
• Latching or Auto−Recovery Timer−Based Overload Protection
• Adjustable Overpower Protection (OPP)
• Fixed or Adjustable Maximum Frequency Clamp
• Fault Pin for Severe Fault Conditions, NTC Compatible for OTP
(9−Pin Version Only)
(Top Views)
ORDERING INFORMATION
See detailed ordering and shipping information on page 2 of
this data sheet.
• 4 ms Soft−Start Timer
© Semiconductor Components Industries, LLC, 2017
1
Publication Order Number:
October, 2017 − Rev. 4
NCP1341/D