NCP1341
High-Voltage,
Quasi-Resonant, Controller
Featuring Valley Lock-Out
Switching
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,
ensuring stable valley switching. This system works down to the 6
th
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.
Features
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8
1
SOIC−9 NB
D SUFFIX
CASE 751BP
1
SOIC−8 NB
D SUFFIX
CASE 751
9
MARKING DIAGRAM
9
1341xz
ALYW
G
1
1341xz
x
z
A
L
Y
W
G
= Specific Device Code
= A or B
= 1, 2, 3 or 4
= Assembly Location
= Wafer Lot
= Year
= Work Week
= Pb−Free Package
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Integrated High−Voltage Startup Circuit with Brownout Detection
Integrated X2 Capacitor Discharge Capability
Wide V
CC
Range from 9 V to 28 V
28 V V
CC
Overvoltage Protection
Abnormal Overcurrent Fault Protection for Winding Short Circuit or
Saturation Detection
Internal Temperature Shutdown
Valley Switching Operation with Valley−Lockout for Noise−Free
Operation
Frequency Foldback with 25 kHz Minimum Frequency Clamp for
Increased Efficiency at Light Loads
Skip Mode with Quiet−Skip Technology for Highest Performance
During Light Loads
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)
4 ms Soft−Start Timer
PIN CONNECTIONS
1
Fault
FMAX
FB
ZCD/OPP
CS
1
FMAX
FB
ZCD/OPP
CS
(Top Views)
HV
VCC
DRV
GND
HV
VCC
DRV
GND
ORDERING INFORMATION
See detailed ordering and shipping information on page 2 of
this data sheet.
©
Semiconductor Components Industries, LLC, 2017
1
October, 2017 − Rev. 4
Publication Order Number:
NCP1341/D
NCP1341
TYPICAL APPLICATION SCHEMATIC
+
+
Vout
NCP1341xx
HV
FMAX
FB
VCC
+
L
N
EMI
Filter
ZCD/OPP DRV
CS
GND
+
Figure 1. NCP1341 8−Pin Typical Application Circuit
+
+
Vout
NCP1341xx
Fault
FMAX
FB
HV
VCC
+
L
N
EMI
Filter
ZCD/OPP DRV
CS
GND
−tº
+
Figure 2. NCP1341 9−Pin Typical Application Circuit
Table 1. ORDERABLE PART NUMBERS
Ordering Code
NCP1341A1D1R2G
NCP1341B1DR2G
NCP1341B1D1R2G
NCP1341B4D1R2G
Device
Marking
1341A1
1341B1
1341B1
1341B4
Pins
9
8
9
9
Fault
Pin
Yes
No
Yes
Yes
FMAX
Pin
Yes
Yes
Yes
Yes
PEM
Yes
Yes
Yes
Yes
OTP
Protection
Latched
Auto−Restart
Auto−Restart
Auto−Restart
Overload
Protection
Latched
Auto−Restart
Auto−Restart
None
Frequency
Clamp
None
None
None
None
Jitter
1.3 kHz
1.3 kHz
1.3 kHz
None
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2
NCP1341
FUNCTIONAL BLOCK DIAGRAM
IFMAX
VDD
TSD
PEM_FMAX
Abnormal OCP
OVLD
OVP
OTP
BO
X2
FMAX
FMAX
Control
QR_FMAX
Fault
Management
VCC(OVP)
X2/BO Detect
+
VCC
Management
HV
FB
Valley/VCO
Control
VCC
Fault
ZCD/OPP
OPP
Control
VFB(open)
IFB
RFB
KFB
OPP
Off−Time
Control
Dead−Time
Control
QR_FMAX
PEM_FMAX
FB
t
tout
Quiet−Skip
Control
S
R
Q
V
CC
Clamp
Jitter Ramp
DRV
GND
FB
÷
PEM
Detect
FB
PEM
PEM
Control
ICS
PEM
OVP
CS
t
LEB1
ILIM1
Detect
OPP
t
OVLD
OVLD
OTP
OVP/OTP
Detect
IOTP
PEM
VDD
On−Time
Control
Fault
VDD
Fault
RFault(clamp)
t
LEB2
ILIM2
Detect
Count 4
Abnormal OCP
VFault(clamp)
8−Pin
9−Pin
Figure 3. NCP1341 Block Diagram
Table 2. PIN FUNCTIONAL DESCRIPTION
8−Pin
−
1
9−Pin
1
2
Pin Name
Fault
FMAX
Function
The controller enters fault mode if the voltage on this pin is pulled above or below the fault
thresholds. A precise pull up current source allows direct interface with an NTC thermistor.
A resistor to ground sets the value for the maximum switching frequency in CCM mode. For ver-
sions x3, it also sets the maximum switching frequency in QR mode. For versions A/B, pulling
this pin above 4 V switches the PEM control method to fixed frequency mode.
Feedback input for the QR Flyback controller. Allows direct connection to an optocoupler.
A resistor divider from the auxiliary winding to this pin provides input to the demagnetization de-
tection comparator and sets the OPP compensation level.
Input to the cycle−by−cycle current limit comparator.
Ground reference.
This is the drive pin of the circuit. The DRV high−current capability (−0.5 /+0.8 A) makes it suit-
able to effectively drive high gate charge power MOSFETs.
This pin is the positive supply of the IC. The circuit starts to operate when V
CC
exceeds 17 V and
turns off when V
CC
goes below 9 V (typical values). After start−up, the operating range is 9 V up
to 28 V.
Removed for creepage distance.
This pin is the input for the high voltage startup and brownout detection circuits. It also contains
the line removal detection circuit to safely discharge the X2 capacitors when the line is removed.
2
3
4
5
6
7
3
4
5
6
7
8
FB
ZCD/OPP
CS
GND
DRV
VCC
−
8
9
10
N/C
HV
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3
NCP1341
Table 3. MAXIMUM RATINGS
Rating
High Voltage Startup Circuit Input Voltage
High Voltage Startup Circuit Input Current
Supply Input Voltage
Supply Input Current
Supply Input Voltage Slew Rate
Fault Input Voltage
Fault Input Current
Zero Current Detection and OPP Input Voltage
Zero Current Detection and OPP Input Current
Maximum Input Voltage (Other Pins)
Maximum Input Current (Other Pins)
Driver Maximum Voltage (Note 1)
Driver Maximum Current
Operating Junction Temperature
Storage Temperature Range
Power Dissipation (T
A
= 25°C, 1 oz. Cu, 42 mm
2
Copper Clad Printed Circuit)
DR2G Suffix, SOIC−8
D1R2G Suffix, SOIC−9
Thermal Resistance (T
A
= 25°C, 1 oz. Cu, 42 mm
2
Copper Clad Printed Circuit)
DR2G Suffix, SOIC−8
D1R2G Suffix, SOIC−9
ESD Capability
Human Body Model per JEDEC Standard JESD22−A114F (All pins except HV)
Human Body Model per JEDEC Standard JESD22−A114F (HV Pin)
Charge Device Model per JEDEC Standard JESD22−C101F
Latch−Up Protection per JEDEC Standard JESD78E
Symbol
V
HV(MAX)
I
HV(MAX)
V
CC(MAX)
I
CC(MAX)
dV
CC
/dt
V
Fault(MAX)
I
Fault(MAX)
V
ZCD(MAX)
I
ZCD(MAX)
V
MAX
I
MAX
V
DRV
I
DRV(SRC)
I
DRV(SNK)
T
J
T
STG
P
D(MAX)
450
330
R
qJA
°C/W
225
300
2000
800
1000
±100
V
V
V
mA
Value
−0.3 to 700
20
−0.3 to 30
30
1
−0.3 to V
CC
+ 0.7 V
10
−0.3 to V
CC
+ 0.7 V
−2/+5
−0.3 to 5.5
10
−0.3 to V
DRV(high)
500
800
−40 to 125
–60 to 150
Unit
V
mA
V
mA
V/ms
V
mA
V
mA
V
mA
V
mA
°C
°C
mW
Stresses exceeding those listed in the Maximum Ratings table may damage the device. If any of these limits are exceeded, device functionality
should not be assumed, damage may occur and reliability may be affected.
1. Maximum driver voltage is limited by the driver clamp voltage, V
DRV(high)
, when V
CC
exceeds the driver clamp voltage. Otherwise, the
maximum driver voltage is V
CC
.
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4
NCP1341
Table 4. ELECTRICAL CHARACTERISTICS:
(V
CC
= 12 V, V
HV
= 120 V, V
Fault
= open, V
FB
= 2 V, V
CS
= 0 V, V
ZCD
= 0 V, V
FMAX
=
0 V, C
VCC
= 100 nF , C
DRV
= 100 pF, for typical values T
J
= 25°C, for min/max values, T
J
is – 40°C to 125°C, unless otherwise noted)
Characteristics
START−UP AND SUPPLY CIRCUITS
Supply Voltage
Startup Threshold
Discharge Voltage During Line Removal
Minimum Operating Voltage
Operating Hysteresis
Internal Latch / Logic Reset Level
Transition from I
start1
to I
start2
V
CC(off)
Delay
Startup Delay
Minimum Voltage for Start−Up Current
Source
Inhibit Current Sourced from V
CC
Pin
Start−Up Current Sourced from V
CC
Pin
Start−Up Circuit Off−State Leakage Cur-
rent
V
cc
= 0 V
V
cc
= V
cc(on)
– 0.5 V
V
HV
= 162.5 V
V
HV
= 325 V
V
HV
= 700 V
V
CC
= V
CC(on)
– 0.5 V
V
FB
= 0 V
f
sw
= 50 kHz, C
DRV
= open
dV/dt = 0.1 V/ms
V
CC
increasing
V
CC
decreasing
V
CC
decreasing
V
CC(on)
− V
CC(off)
V
CC
decreasing
V
CC
increasing, I
HV
= 650
mA
V
CC
decreasing
Delay from V
CC(on)
to DRV Enable
V
V
CC(on)
V
CC(X2_reg)
V
CC(off)
V
CC(HYS)
V
CC(reset)
V
CC(inhibit)
t
delay(VCC_off)
t
delay(start)
V
HV(MIN)
I
start1
I
start2
I
HV(off1)
I
HV(off2)
I
HV(off3)
I
CC1
I
CC2
I
CC3
V
CC(OVP)
t
delay(VCC_OVP)
t
line(removal)
t
line(discharge)
t
line(detect)
V
CC
= 20 V
I
CC(discharge)
V
HV(discharge)
V
HV
increasing
V
HV
decreasing
V
HV
increasing
V
HV
decreasing
V
DRV
from 10% to 90%
V
DRV
from 90% to 10%
V
BO(start)
V
BO(stop)
V
BO(HYS)
t
BO(stop)
t
DRV(rise)
t
DRV(fall)
I
DRV(SRC)
I
DRV(SNK)
V
CC
= V
CC(off)
+ 0.2 V, R
DRV
= 10 kW
V
CC
= 30 V, R
DRV
= 10 kW
V
Fault
= 0 V
V
DRV(high1)
V
DRV(high2)
V
DRV(low)
V
FB(open)
K
FB
V
FB
= 0.4 V
R
FB
I
FB
16.0
17.0
8.5
7.5
4.5
0.40
25
–
–
0.2
2.4
–
–
–
−
−
−
27
25
17.0
18.0
9.0
–
6.5
0.70
32
–
–
0.5
3.75
–
–
–
0.115
0.230
1.0
28
32
18.0
19.0
9.5
–
7.5
1.05
40
500
40
0.65
5.0
15
20
50
0.150
0.315
1.5
29
40
V
ms
ms
ms
ms
mA
V
ms
ms
V
mA
mA
mA
Conditions
Symbol
Min
Typ
Max
Unit
Supply Current
Fault or Latch
Skip Mode (excluding FB current)
Operating Current
V
CC
Overvoltage Protection Threshold
V
CC
Overvoltage Protection Delay
X2 CAPACITOR DISCHARGE
Line Voltage Removal Detection Timer
Discharge Timer Duration
Line Detection Timer Duration
V
CC
Discharge Current
HV Discharge Level
BROWNOUT DETECTION
System Start−Up Threshold
Brownout Threshold
Hysteresis
Brownout Detection Blanking Time
GATE DRIVE
Rise Time
Fall Time
Current Capability
Source
Sink
High State Voltage
Low Stage Voltage
FEEDBACK
Open Pin Voltage
V
FB
to Internal Current Setpoint Division
Ratio
Internal Pull−Up Resistor
Internal Pull−Up Current
mA
65
21
21
13
–
100
32
32
18
–
135
43
43
23
30
107
93
9.0
40
112
98
14
70
116
102
–
100
V
V
V
ms
–
–
–
–
8.0
10
–
20
5
500
800
–
12
–
40
30
–
–
–
14
0.25
ns
ns
mA
V
V
4.9
−
350
92
5.0
3
400
100
5.1
−
420
108
V
–
kW
mA
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