ONSEMI NCP1652_10

NCP1652, NCP1652A
High-Efficiency Single
Stage Power Factor
Correction and Step-Down
Controller
The NCP1652 is a highly integrated controller for implementing
power factor correction (PFC) and isolated step down ac−dc power
conversion in a single stage, resulting in a lower cost and reduced part
count solution. This controller is ideal for notebook adapters, battery
chargers and other off−line applications with power requirements
between 75 W and 150 W. The single stage is based on the flyback
converter and it is designed to operate in continuous conduction
(CCM) or discontinuous conduction (DCM) modes.
The NCP1652 increases the system efficiency by incorporating a
secondary driver with adjustable nonoverlap delay for controlling a
synchronous rectifier switch in the secondary side, an active clamp
switch in the primary or both. In addition, the controller features a
proprietary Soft−Skip™ to reduce acoustic noise at light loads. Other
features found in the NCP1652 include a high voltage startup circuit,
voltage feedforward, brown out detector, internal overload timer, latch
input and a high accuracy multiplier.
Features
• Dual Control Outputs with Adjustable Non Overlap Delay for
•
•
•
•
•
•
•
•
•
•
•
•
Driving a Synchronous Rectifier Switch, an Active Clamp Switch or
Both
Voltage Feedforward Improves Loop Response
Frequency Jittering Reduces EMI Signature
Proprietary Soft−Skip™ at Light Loads Reduces Acoustic Noise
Brown Out Detector
Internal 150 ms Fault Timer
Independent Latch−Off Input Facilitates Implementation of
Overvoltage and Overtemperature Fault Detectors
Single Stage PFC and Isolated Step Down Converter
Continuous or Discontinuous Conduction Mode Operation
Average Current Mode Control (ACMC), Fixed Frequency Operation
High Accuracy Multiplier Reduces Input Line Harmonics
Adjustable Operating Frequency from 20 kHz to 250 kHz
These are Pb−Free Devices
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MARKING
DIAGRAMS
20
SO−20 WB
DW SUFFIX
CASE 751D
NCP1652
AWLYYWWG
1
NCP1652G
AWLYWW
SOIC−16
D SUFFIX
CASE 751B
A
WL
YY
WW
G
NCP1652AG
AWLYWW
= Assembly Location
= Wafer Lot
= Year
= Work Week
= Pb−Free Package
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 32 of this data sheet.
Typical Applications
•
•
•
•
Notebook Adapter
High Current Battery Chargers
Front Ends for Distributed Power Systems
High Power Solid State Lighting
© Semiconductor Components Industries, LLC, 2010
April, 2010 − Rev. 3
1
Publication Order Number:
NCP1652/D
NCP1652, NCP1652A
SO−20 WB
CT 1
SOIC−16
Ramp Comp 2
19 NC
AC IN 3
18 NC
17 GND
VFF 5
16 Out B
CM 6
15 Out A
NC 7
14 VCC
NC 8
13 Ispos
Latch−Off 10
16 Startup
Ramp Comp 2
FB 4
AC COMP 9
CT 1
20 Startup
15 GND
AC IN 3
14 OUT B
FB 4
13 OUT A
VFF 5
12 VCC
CM 6
11 Ispos
AC COMP 7
10 Iavg
Latch−Off 8
9 Rdelay
(Top View)
12 Iavg
11 Rdelay
Figure 1. Pin Connections
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2
NCP1652, NCP1652A
FB overload
comparator
Jitter
FB
CT
+
Jitter
Adj.
+
−
Overload
Timer
tOVLD
Enable
S
Q
R
VOVLD
Clock
Oscillator
DC Max
Sawtooth
DC Max
VFF
+
V Brown−Out
FF
Comparator
−
+
VBO
Ramp. Comp.
OVLD
Startup
Enable
x2
counter
Reset
Out
Dual HV
start−up
current source
BO
Ramp Comp
Adj.
VCC(off) HV current
Reset
Ramp
Comp
+
−
+
VCC
Management
Start
VDD
Reset
V
CCOK
AC In skip
comparator
VDD
VSSKIP(sync)
VDD
GND
Output
Driver
Clock
Soft−skip Ramp
R
FB
FB skip
Comparator
+
−
+
Inst. current B
VSSKIP
AC IN
+
Q
R
−
V−to−I
FB
S
+
Ramp Comp
OUTB
Delay
Transient Load Detect
Comparator
+
−
VSSKIP(TLD)
OUTA
Output
Driver
PWM Skip
Comparator
21.33kW
V−to−I
Reference
Generator
+
gm
−
V−to−I
+ inverter
+
−
AC error
Amplifier
VFF
21.33kW
VCC
PWM
comparator
+
BO
OVLD
4V
CM
Latch
Inst. current A
Blanking
tLEB
gm
AC COMP
Blanking
Inst.
current B
VDD
VCCOK
tLEB
−
+
FB
VFF
Delay
Adj.
DC Max
Delay
tSSKIP
Start
Terminate
Ispos
Current sense
amplifier
OVP Comparator
+
Ilatch(clamp)
Iavg
+
−
Vlatch(high)
blanking
tLatch(delay)
Latch−Off
OTP Comparator
Ilatch(shdn)
Vlatch(clamp)
+
S
−
+
Q
R
Vlatch(low)
Reset
Figure 2. Detailed Block Diagram
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3
Latch
Delay
Rdelay
NCP1652, NCP1652A
PIN FUNCTION DESCRIPTION
Pin
16 Pin
20 Pin
Symbol
Description
1
1
CT
An external timing capacitor (CT) sets the oscillator frequency. A sawtooth between 0.2 V and 4
V sets the oscillator frequency and the gain of the multiplier.
2
2
RAMP COMP
A resistor (RRC) between this pin and ground adjust the amount of ramp compensation that is
added to the current signal. Ramp compensation is required to prevent subharmonic oscillations. This pin should not be left open.
3
3
AC IN
The scaled version of the full wave rectified input ac wave is connected to this pin by means of
a resistive voltage divider. The line voltage information is used by the multiplier.
4
4
FB
An error signal from an external error amplifier circuit is fed to this pin via an optocoupler or
other isolation circuit. The FB voltage is a proportional of the load of the converter. If the voltage
on the FB pin drops below VSSKIP the controller enters Soft−Skip™ to reduce acoustic noise.
5
5
VFF
Feedforward input. A scaled version of the filtered rectified line voltage is applied by means of a
resistive divider and an averaging capacitor. The information is used by the Reference Generator to regulate the controller.
6
6
CM
Multiplier output. A capacitor is connected between this pin and ground to filter the modulated
output of the multiplier.
7
NC
8
NC
7
9
AC COMP
Sets the pole for the ac reference amplifier. The reference amplifier compares the low frequency component of the input current to the ac reference signal. The response must be slow
enough to filter out most of the high frequency content of the current signal that is injected from
the current sense amplifier, but fast enough to cause minimal distortion to the line frequency
information. The pin should not be left open.
8
10
Latch
Latch−Off input. Pulling this pin below 1.0 V (typical) or pulling it above 7.0 V (typical) latches
the controller. This input can be used to implement an overvoltage detector, an overtemperature
detector or both. Refer to Figure 69 for a typical implementation.
9
11
Rdelay
A resistor between this pin and ground sets the non−overlap time delay between OUTA and
OUTB. The delay is adjusted to prevent cross conduction between the primary MOSFET and
synchronous rectification MOSFET or optimize the resonant transition in an active clamp stage.
10
12
IAVG
An external resistor and capacitor connected from this terminal to ground, to set and stabilizes
the gain of the current sense amplifier output that drives the ac error amplifier.
11
13
ISpos
Positive current sense input. Connects to the positive side of the current sense resistor.
12
14
VCC
Positive input supply. This pin connects to an external capacitor for energy storage. An internal
current source supplies current from the STARTUP pin VCC. Once the voltage on VCC reaches
approximately 15.3 V, the current source turns off and the outputs are enabled. The drivers are
disabled once VCC reaches approximately 10.3 V. If VCC drops below 0.85 V (typical), the startup current is reduced to less than 500 mA.
13
15
OUTA
Drive output for the main flyback power MOSFET or IGBT. OUTA has a source resistance of
13 W (typical) and a sink resistance of 8 W (typical).
14
16
OUTB
Secondary output of the PWM Controller. It can be used to drive synchronous rectifier, and
active clamp switch, or both. OUTB has source and sink resistances of 22 W (typical) and 11
(typical), respectively.
15
17
GND
Ground reference for the circuit.
18
NC
19
NC
20
HV
16
Connect the rectified input line voltage directly to this pin to enable the internal startup regulator.
A constant current source supplies current from this pin to the capacitor connected to the VCC
pin, eliminating the need for a startup resistor. The charge current is typically 5.5 mA. Maximum
input voltage is 500 V.
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4
NCP1652, NCP1652A
MAXIMUM RATINGS (Notes 1 and 2)
Rating
Symbol
Value
Unit
Start_up Input Voltage
Start_up Input Current
VHV
IHV
−0.3 to 500
$100
V
mA
Power Supply Input Voltage
Power Supply Input Current
VCC
ICC
−0.3 to 20
$100
V
mA
Latch Input Voltage
Latch Input Current
VLatch
ILatch
−0.3 to 10
$100
V
mA
OUTA Pin Voltage
OUTA Pin Current
VoutA
IoutA
−0.3 to 20
$1.0
V
A
OUTB Pin Voltage
OUTB Pin Current
VoutB
IoutB
−0.3 to 20
$600
V
mA
−0.3 to 6.5
$100
V
mA
All Other Pins Voltage
All Other Pins Current
Thermal Resistance, Junction−to−Air
0.1 in” Copper
0.5 in” Copper
qJA
130
110
°C/W
Thermal Resistance, Junction−to−Lead
RΘJL
50
°C/W
Maximum Power Dissipation @ TA = 25°C
PMAX
0.77
W
TJ
−40 to 125
°C
TSTG
−55 to 150
°C
Operating Temperature Range
Storage Temperature Range
Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the
Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect
device reliability.
1. This device series contains ESD protection and exceeds the following tests:
16 pin package:
Pin 1−15: Human Body Model 2000 V per JEDEC standard JESD22, Method A114.
Machine Model 200 V per JEDEC standard JESD22, Method A115.
Pin 16 is the high voltage startup of the device and is rated to the maximum rating of the part, 500 V.
20 pin package:
Pin 1−19: Human Body Model 2000 V per JEDEC standard JESD22, Method A114.
Machine Model 200 V per JEDEC standard JESD22, Method A115.
Pin 20 is the high voltage startup of the device and it is rated to the maximum
rating of the part, or 500 V.
2. This device contains Latchup protection and exceeds ±100 mA per JEDEC Standard JESD78.
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5
NCP1652, NCP1652A
VCC
EMI Filter
Latch
+
NTC
+
+
_
FB
1
CT
HV
Ramp Comp
FB
GND
AC IN
OUTB
FB
OUTA
VCC
VFF
NCP1652
CM
Ispos
AC COMP
Latch
VCC
Iavg
10
11
LATCH
Rdelay
Figure 3. Typical Application Schematic
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6
NCP1652, NCP1652A
ELECTRICAL CHARACTERISTICS (VCC = 15 V, VAC IN = 3.8 V, VFB = 2.0 V, VFF = 2.4 V, VLatch = open, VISPOS = −100 mV,
COUTA = 1 nF, CT = 470 pF, CIAVG = 0.27 nF, CLatch = 0.1 nF, CM = 10 nF, RIAVG = 76.8 kW, Rdelay = 49.9 kW,
COUTB = 330 pF, RRC = 43 kW, For typical Value TJ = 25°C, for min/max values TJ = −40°C to 125°C, unless otherwise noted)
Symbol
Min
Typ
Max
Unit
fosc
90
100
110
kHz
Frequency Modulation in Percentage
of fOSC
–
6.8
–
%
Frequency Modulation Period
–
6.8
–
ms
Parameter
Test Condition
OSCILLATOR
Frequency
Ramp Peak Voltage
VCT(peak)
–
4.0
–
V
Ramp Valley Voltage
VCT(valley)
–
0.10
–
V
D
94
−
–
%
VRCOMP(peak)
–
4
–
V
40
–
mV
Maximum Duty Ratio
Rdelay = open
Ramp Compensation Peak Voltage
AC ERROR AMPLIFIER
Input Offset Voltage (Note 3)
Ramp IAVG, VFB = 0 V
Error Amplifier Transconductance
ACVIO
gm
–
100
–
mS
Source Current
VAC COMP = 2.0 V, VAC IN = 2.0 V,
VFF = 1.0 V
IEA(source)
25
70
–
mA
Sink Current
VAC COMP = 2.0 V, VA C_IN = 2.0 V,
VFF = 5.0 V
IEA(sink)
−25
−70
–
mA
VISPOS = 0 V
CAIbias
40
53
80
mA
VAC COMP = 5.0 V, VISpos = 0 V
CAVIO
−20
0
20
mV
force OUTA high, VAC COMP = 3.0 V,
ramp VISPOS, VRamp_Comp = open
VILIM
0.695
0.74
0.77
V
tLEB
–
200
–
ns
–
1.5
–
MHz
PWMk
4.0
5.3
6.0
V/V
ISVk
15.4
18.5
23
V/V
k
–
0.55
–
V
CURRENT AMPLIFIER
Input Bias Current
Input Offset Voltage
Current Limit Threshold
Leading Edge Blanking Duration
Bandwidth
PWM Output Voltage Gain
Current Limit Voltage Gain (See
Current Sense Section)
PWMk +
4
(V ILIM * C AVIO)
ISVK +
V (AVG)
VI SPOS
REFERENCE GENERATOR
Reference Generator Gain
k+
V AC_REF @ V FF 2
V FB @ V AC_IN
Reference Generator output voltage
(low input ac line and full load)
VAC IN = 1.2 V, VFF = 0.765 V,
VFB = 4 V
RGout1
3.61
4.36
4.94
Vpk
Reference Generator output voltage
(high input ac line and full load)
VAC IN = 3.75 V, VFF = 2.39 V,
VFB = 4.0 V
RGout2
1.16
1.35
1.61
Vpk
Reference Generator output Voltage
(low input as line and minimum load)
VAC IN = 1.2 V, VFF = 0.765 V,
VFB = 2.0 V
RGout3
1.85
2.18
2.58
Vpk
Reference Generator output voltage
(high input ac line and minimum load)
VAC IN = 3.75 V, VFF = 2.39 V,
VFB = 2.0 V
RGout4
0.55
0.65
0.78
Vpk
RGoffset
−100
–
100
mV
Reference Generator output offset
voltage
3. Guaranteed by Design
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NCP1652, NCP1652A
ELECTRICAL CHARACTERISTICS (VCC = 15 V, VAC IN = 3.8 V, VFB = 2.0 V, VFF = 2.4 V, VLatch = open, VISPOS = −100 mV,
COUTA = 1 nF, CT = 470 pF, CIAVG = 0.27 nF, CLatch = 0.1 nF, CM = 10 nF, RIAVG = 76.8 kW, Rdelay = 49.9 kW,
COUTB = 330 pF, RRC = 43 kW, For typical Value TJ = 25°C, for min/max values TJ = −40°C to 125°C, unless otherwise noted)
Parameter
Test Condition
Symbol
Min
Typ
Max
Unit
IAC IN(IB)
–
0.01
–
mA
VOUTA = 1 V
IOUTA = 100 mA
RSNK1
RSRC1
–
–
8
10.8
18
24
VOUTB = 1 V
IOUTB = 100 mA
RSNK2
RSRC2
–
–
10
21
22
44
Rise Time (10% to 90%)
OUTA
OUTB
tr1
tr2
–
–
40
25
–
–
Fall Time (90% to 10%)
OUTA
OUTB
tf1
tf2
–
–
20
10
–
–
VOUTA(low)
VOUTB(low)
–
–
1.0
1.0
100
100
tdelay(range)
0.08
–
2.8
AC INPUT
Input Bias Current Into Reference
Multiplier & Current Compensation
Amplifier
DRIVE OUTPUTS A and B
Drive Resistance (Thermally Limited)
OUTA Sink
OUTA Source
OUTB Sink
OUTB Source
DRV Low Voltage
OUTA
OUTB
IOUTA = 100 mA
IOUTB = 100 mA
Non−Overlap Adjustable Delay Range
(Note 3)
Non−Overlap Adjustable Delay
Leading
Trailing
Measured at 50% of VOUT,
COUTA = COUTB = 100 pF
OUTA Rising to OUTB falling
OUTB Rising to OUTA falling
W
ns
ns
mV
ms
ns
tdelay(lead)
tdelay(trail)
250
250
450
420
550
550
OUTA Rising to OUTB Falling or OUTB
Rising to OUTA Falling
tdelay(match)
–
–
55
%
Skip Synchronization to ac Line
Voltage Threshold
VACIN Increasing, VFB = 1.5 V
VSSKIP(SYNC)
210
267
325
mV
Skip Synchronization to ac Line
Voltage Threshold Hysteresis
VACIN Decreasing
VSSKIP
(SYNCHYS)
–
40
–
mV
Skip Ramp Period (Note 3)
tSSKIP
−
2.5
–
ms
Skip Voltage Threshold
NCP1652
NCP1652A
VSSKIP
1.04
0.36
1.24
0.41
1.56
0.46
Skip Voltage Hysteresis
VSSKIP(HYS)
45
90
140
mV
VSSKIP(TLD) = VSSKIP +0.55 V
VSSKIP(TLD)
−
1.75
−
V
VFB= 0.5 V
IFB
600
750
920
mA
RFB
–
6.7
–
kW
VFB(open)
5.3
5.7
6.3
V
VCC Increasing
VCC Decreasing
VCC Decreasing
VCC(on)
VCC(off)
VCC(reset)
14.3
9.3
–
15.4
10.2
7.0
16.3
11.3
–
VHV = 40 V, Iinhibit = 500 mA
Vinhibit
−
0.83
1.15
Non−Overlap Adjustable Delay
Matching
Soft−Skip]
Skip Transient Load Detect Threshold
(Note 3)
V
FEEDBACK INPUT
Pull−Up Current Source
Pull−Up Resistor
Open Circuit Voltage
STARTUP AND SUPPLY CIRCUITS
Supply Voltage
Startup Threshold
Minimum Operating Voltage
Logic Reset Voltage
Inhibit Threshold Voltage
3. Guaranteed by Design
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8
V
V
NCP1652, NCP1652A
ELECTRICAL CHARACTERISTICS (VCC = 15 V, VAC IN = 3.8 V, VFB = 2.0 V, VFF = 2.4 V, VLatch = open, VISPOS = −100 mV,
COUTA = 1 nF, CT = 470 pF, CIAVG = 0.27 nF, CLatch = 0.1 nF, CM = 10 nF, RIAVG = 76.8 kW, Rdelay = 49.9 kW,
COUTB = 330 pF, RRC = 43 kW, For typical Value TJ = 25°C, for min/max values TJ = −40°C to 125°C, unless otherwise noted)
Parameter
Test Condition
Symbol
Min
Typ
Max
Unit
VHV = 40 V, VCC = 0.8 * Vinhibit
Iinhibit
40
-
500
mA
Istart = 0.5 mA, VCC = VCC(on) – 0.5 V
Vstart(min)
–
–
40
V
VCC = VCC(on) – 0.5 V, VFB = Open
Istart
3.0
5.62
8.0
mA
VHV = 400 V, TJ = 25°C
TJ = −40°C to 125°C
IHV(off)
–
–
17
15
40
80
VFB = Open
fOSC [ 100 kHz
ICC1
ICC2
–
–
0.72
6.25
1.2
7.2
Overload Timer
tOVLD
120
162
360
ms
Overload Detect Threshold
VOVLD
4.7
4.9
5.2
V
STARTUP AND SUPPLY CIRCUITS
Inhibit Bias Current
Minimum Startup Voltage
Startup Current
Off−State Leakage Current
Supply Current
Device Disabled (Overload)
Device Switching
mA
mA
FAULT PROTECTION
Brown−Out Detect Threshold (entering
fault mode)
VFF Decreasing, VFB = 2.5 V,
VAC IN = 2.0 V
VBO(low)
0.41
0.45
0.49
V
Brown−Out Exit Threshold (exiting
fault mode)
VFF Increasing, VFB = 2.5 V,
VAC IN = 2.0 V
VBO(high)
0.57
0.63
0.69
V
VBO(HYS)
−
174
−
mV
Vlatch(low)
0.9
0.98
1.1
V
Brown−Out Hysteresis
LATCH INPUT
Pull−Down Latch Voltage Threshold
Pull−Up Latch Voltage Threshold
VLatch Decreasing
VLatch Increasing
Vlatch(high)
5.6
7.0
8.4
V
VLatch = Vlatch(high)
tlatch(delay)
30
56
90
ms
Latch Clamp Current (Going Out)
VLatch = 1.5 V
Ilatch(clamp)
42
51
58
mA
Latch Clamp Voltage (ILatch Going In)
ILatch = 50 mA
Vlatch(clamp)
2.5
3.27
4.5
V
VLatch Increasing
Ilatch(shdn)
−
95
−
mA
Latch Propagation Delay
Latch−Off Current Shutdown
(Going In)
3. Guaranteed by Design
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NCP1652, NCP1652A
8.0
OSCILLATOR FREQUENCY
MODULATION (%)
fOSC, OSCILLATOR FREQUENCY (kHz)
110
105
100
95
90
−50
−25
0
25
50
75
100
125
7.5
7.0
6.5
6.0
−50
150
−25
Figure 4. Oscillator Frequency (fOSC) vs.
Junction Temperature
VCT(peak), OSCILLATOR RAMP PEAK
VOLTAGE (V)
7.0
6.5
−25
0
25
50
75
100
125
150
75
100
125
150
4.05
4.0
3.95
3.9
3.85
3.8
−50
−25
0
25
50
75
100
125
TJ, JUNCTION TEMPERATURE (°C)
TJ, JUNCTION TEMPERATURE (°C)
Figure 6. Oscillator Frequency Modulation
Period vs. Junction Temperature
Figure 7. Ramp Peak Voltage vs. Junction
Temperature
100
D, MAXIMUM DUTY RATIO (%)
50
4.1
7.5
98
96
94
92
90
−50
25
Figure 5. Oscillator Frequency Modulation in
Percentage of fOSC vs. Junction Temperature
8.0
6.0
−50
0
TJ, JUNCTION TEMPERATURE (°C)
−25
0
25
50
75
100
125
TJ, JUNCTION TEMPERATURE (°C)
150
VCOMP(peak), RAMP COMP PEAK VOLTAGE (V)
OSCILLATOR FREQUENCY MODULATION PERIOD (ms)
TJ, JUNCTION TEMPERATURE (°C)
150
4.1
4.05
4.0
3.95
3.9
3.85
3.8
−50
Figure 8. Maximum Duty Ratio vs. Junction
Temperature
−25
0
25
50
75
100
125
TJ, JUNCTION TEMPERATURE (°C)
Figure 9. Ramp Compensation Peak Voltage
vs. Junction Temperature
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10
150
NCP1652, NCP1652A
IEA(SINK), ERROR AMPLIFIER SINK
CURRENT (mA)
IEA(SOURCE), ERROR AMPLIFIER
SOURCE CURRENT (mA)
90
85
80
75
70
65
60
55
50
−50
−25
0
25
50
75
100
125
90
85
80
75
70
65
60
55
50
−50
150
−25
0
25
50
75
100
125
TJ, JUNCTION TEMPERATURE (°C)
TJ, JUNCTION TEMPERATURE (°C)
Figure 10. Error Amplifier Source Current vs.
Junction Temperature
Figure 11. Error Amplifier Sink Current vs.
Junction Temperature
150
CAVBIAS, CURRENT AMPLIFIER
INPUT BIAS CURRENT (mA)
60.0
57.5
55.0
52.5
50.0
47.5
45.0
42.5
40.0
−50
−25
0
25
50
75
100
125
150
TJ, JUNCTION TEMPERATURE (°C)
770
6.0
PWMk, PWM VOLTAGE GAIN (V/V)
VILIM, CURRENT LIMIT THRESHOLD
(mV)
Figure 12. Current Amplifier Input Bias
Current vs. Junction Temperature
760
750
740
730
720
710
700
−50
−25
0
25
50
75
100
125
150
5.8
5.6
5.4
5.2
5.0
−50
−25
0
25
50
75
100
125
TJ, JUNCTION TEMPERATURE (°C)
TJ, JUNCTION TEMPERATURE (°C)
Figure 13. Current Limit Threshold vs.
Junction Temperature
Figure 14. PWM Output Voltage Gain vs.
Junction Temperature
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150
NCP1652, NCP1652A
5.25
20
19
18
17
−25
0
25
50
75
100
125
150
RGout1
4.75
4.25
3.75
3.25
2.75
RGout3
2.25
1.75
RGout2
1.25
RGout4
0.75
0.25
−50
−25
0
25
50
75
100
125
TJ, JUNCTION TEMPERATURE (°C)
TJ, JUNCTION TEMPERATURE (°C)
Figure 15. Oscillator CS Limit Voltage Gain vs.
Junction Temperature
Figure 16. Oscillator Reference Generator
Output Voltage vs. Junction Temperature
14
16
12
14
RSRC1, OUTA SOURCE
RESISTANCE (W)
RSNK1, OUTA SINK DRIVE
RESISTANCE (W)
16
−50
10
8.0
6.0
4.0
−50
−25
0
25
50
75
100
125
150
150
12
10
8.0
6.0
−50
−25
0
25
50
75
100
125
150
TJ, JUNCTION TEMPERATURE (°C)
TJ, JUNCTION TEMPERATURE (°C)
Figure 17. OUTA Sink Resistance vs. Junction
Temperature
Figure 18. OUTA Source Drive Resistance vs.
Junction Temperature
16
RSNK2, OUTB SINK DRIVE
RESISTANCE (W)
RGout, REFERENCE GENERATOR
OUTPUT VOLTAGE (V)
21
32
VCC = 15 V
VCC = 15 V
CI = 100 pF
30
14
RSRC2, OUTB SOURCE
RESISTANCE (W)
ISVk, CURRENT LIMIT VOLTAGE
GAIN (V/V)
22
12
10
8.0
28
26
24
22
20
18
16
6.0
−50
−25
0
25
50
75
100
125
150
14
−50
TJ, JUNCTION TEMPERATURE (°C)
−25
0
25
50
75
100
125
150
TJ, JUNCTION TEMPERATURE (°C)
Figure 19. OUTB Sink Resistance vs.
Junction Temperature
Figure 20. OUTB Source Drive Resistance vs.
Junction Temperature
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NCP1652, NCP1652A
160
VOUTB(LOW), OUTB LOW VOLTAGE
(mV)
VOUTA(low), OUTA LOW VOLTAGE
(mV)
130
110
90
70
50
30
−50
−25
0
25
50
75
100
125
TJ, JUNCTION TEMPERATURE (°C)
150
140
120
100
80
60
−50
Figure 21. OUTA Low Voltage vs. Junction
Temperature
tdelay, NON−OVERLAP ADJUSTABLE
DELAY MATCHING (%)
tdelay, NON−OVERLAP ADJUSTABLE
DELAY (ns)
500
OUTA Rising to OUTB Falling
450
OUTB Rising to OUTA Falling
400
350
−25
0
25
50
75
100
125
150
7
5
3
1
−50
−25
0
25
50
75
100
125
TJ, JUNCTION TEMPERATURE (°C)
TJ, JUNCTION TEMPERATURE (°C)
Figure 23. Non−Overlap Adjustable Delay vs.
Junction Temperature
Figure 24. Non−Overlap Adjustable Delay
Matching vs. Junction Temperature
300
150
1.25
VSSKIP, SKIP VOLTAGE THRESHOLD
(V)
VSSKIP(SYNC), SKIP SYNC TO AC
LINE VOLTAGE THRESHOLD (mV)
150
9
550
280
1.24
260
1.23
240
1.22
220
200
−50
0
25
50
75
100
125
TJ, JUNCTION TEMPERATURE (°C)
Figure 22. OUTB Low Voltage vs. Junction
Temperature
600
300
−50
−25
1.21
−25
0
25
50
75
100
125
150
1.20
−50
−25
0
25
50
75
100
125
150
TJ, JUNCTION TEMPERATURE (°C)
TJ, JUNCTION TEMPERATURE (°C)
Figure 25. Skip Synchronization to ac Line
Voltage Threshold vs. Junction Temperature
Figure 26. Skip Voltage Threshold vs. Junction
Temperature
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780
100
IFB, FEEDBACK PULL−UP CURRENT
SOURCE (mA)
VSSKIP, SKIP VOLTAGE HYSTERESIS
(mV)
NCP1652, NCP1652A
95
90
85
80
−50
−25
0
25
50
75
100
125
150
730
705
680
−50
−25
0
25
50
75
100
125
150
TJ, JUNCTION TEMPERATURE (°C)
TJ, JUNCTION TEMPERATURE (°C)
Figure 27. Skip Voltage Hysteresis vs.
Junction Temperature
Figure 28. Feedback Pull−Up Current Source
vs. Junction Temperature
15.75
VCC(on), STARTUP THRESHOLD (V)
6.2
6.0
5.8
5.6
5.4
5.2
−50
−25
0
25
50
75
100
125
150
15.55
15.35
15.15
14.95
14.75
−50
−25
0
25
50
75
100
125
TJ, JUNCTION TEMPERATURE (°C)
TJ, JUNCTION TEMPERATURE (°C)
Figure 29. Feedback Open Circuit Voltage vs.
Junction Temperature
Figure 30. Startup Threshold vs. Junction
Temperature
10.5
VCC(off), MINIMUM OPERATING
VOLTAGE (V)
VFB(open), FEEDBACK OPEN
CIRCUIT VOLTAGE (V)
755
10.3
10.1
9.9
9.7
9.5
−50
−25
0
25
50
75
100
TJ, JUNCTION TEMPERATURE (°C)
125
Figure 31. Minimum Operating Voltage vs.
Junction Temperature
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150
150
NCP1652, NCP1652A
Iinhibit, INHIBIT BIAS CURRENT (mA)
950
900
850
800
750
700
650
−50
Vstartup(min), MINIMUM STARTUP
VOLTAGE (V)
25.0
24.5
−25
0
25
50
75
100
125
310
290
270
250
−50
−25
0
25
50
75
100
125
TJ, JUNCTION TEMPERATURE (°C)
Figure 33. Inhibit Bias Current vs. Junction
Temperature
23.5
23.0
22.5
−25
0
25
150
6.0
50
75
100
125
150
5.8
5.6
5.4
5.2
5.0
−50
−25
0
25
50
75
100
125
TJ, JUNCTION TEMPERATURE (°C)
TJ, JUNCTION TEMPERATURE (°C)
Figure 34. Minimum Startup Voltage vs.
Junction Temperature
Figure 35. Startup Current vs. Junction
Temperature
150
850
ICC1, SUPPLY CURRENT DEVICE
DISABLED (mA)
30
IHV(off), OFF−STATE LEAKAGE
CURRENT (mA)
330
TJ, JUNCTION TEMPERATURE (°C)
24.0
25
20
15
10
−50
350
Figure 32. Inhibit Threshold Voltage vs.
Junction Temperature
VCC = VCC − 0.5 V
Istart = 0.5 mA
22.0
−50
150
Istart, STARTUP CURRENT (mA)
Vinhibit, INHIBIT THRESHOLD
VOLTAGE (V)
1000
−25
0
25
50
75
100
125
150
825
800
775
750
725
700
675
650
−50
−25
0
25
50
75
100
125
TJ, JUNCTION TEMPERATURE (°C)
TJ, JUNCTION TEMPERATURE (°C)
Figure 36. Off−State Leakage Current vs.
Junction Temperature
Figure 37. Supply Current Device Disabled
(Overload) vs. Junction Temperature
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150
NCP1652, NCP1652A
200
tOVLD, OVERLOAD TIMER (ms)
ICC2, SUPPLY CURRENT DEVICE
SWITCHING (mA)
6.75
6.55
6.35
6.15
5.95
5.75
−50
−25
0
25
50
75
100
125
150
140
120
100
−50
25
50
75
100
125
Figure 39. Overload Timer vs. Junction
Temperature
150
500
5.1
4.9
4.7
−25
0
25
50
75
100
125
TJ, JUNCTION TEMPERATURE (°C)
150
480
460
440
420
400
−50
−25
Figure 40. Overload Detect Threshold vs.
Junction Temperature
0
25
50
75
100
125
TJ, JUNCTION TEMPERATURE (°C)
150
Figure 41. Brown−Out Detect Threshold vs.
Junction Temperature
180
650
640
VBO(HYS), BROWN−OUT
HYSTERESIS (mV)
VBO(high), BROWN−OUT EXIT
THRESHOLD (mV)
0
Figure 38. Supply Current Device Switching
vs. Junction Temperature
5.3
630
620
610
600
−50
−25
TJ, JUNCTION TEMPERATURE (°C)
VBO(low), BROWN−OUT DETECT
THRESHOLD (mV)
VOVLD, OVERLOAD DETECT
THRESHOLD (V)
160
TJ, JUNCTION TEMPERATURE (°C)
5.5
4.5
−50
180
−25
0
25
50
75
100
125
150
175
170
165
160
−50
−25
0
25
50
75
100
125
150
TJ, JUNCTION TEMPERATURE (°C)
TJ, JUNCTION TEMPERATURE (°C)
Figure 42. Brown−Out Exit Threshold vs.
Junction Temperature
Figure 43. Brown−Out Hysteresis vs. Junction
Temperature
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NCP1652, NCP1652A
7.5
VCC
VLATCH(low_HYS), LATCH PULL−UP
THRESHOLD (V)
VLATCH(low), LATCH PULL−DOWN
VOLTAGE THRESHOLD (mV)
1000
980
960
940
920
900
−50
−25
0
25
50
75
100
125
7.1
6.9
6.7
6.5
−50
150
−25
0
25
50
75
100
125
TJ, JUNCTION TEMPERATURE (°C)
TJ, JUNCTION TEMPERATURE (°C)
Figure 44. Latch Pull−Down Voltage Threshold
vs. Junction Temperature
Figure 45. Latch Pull−Up Threshold vs.
Junction Temperature
7.5
VLATCH(delay), LATCH PROPAGATION
DELAY (ms)
7.3
7.1
6.9
6.7
6.5
−50
150
60
−25
0
25
50
75
100
125
150
58
56
54
52
50
−50
−25
0
25
50
75
100
125
TJ, JUNCTION TEMPERATURE (°C)
TJ, JUNCTION TEMPERATURE (°C)
Figure 46. Latch Pull−Up Voltage Threshold
vs. Junction Temperature
Figure 47. Latch Propagation Delay vs.
Junction Temperature
55
ILATCH(clamp), LATCH CLAMP
CURRENT (mA)
VLATCH(lhigh), LATCH PULL−UP
VOLTAGE THRESHOLD (V)
7.3
54
53
52
51
50
−50
−25
0
25
50
75
100
TJ, JUNCTION TEMPERATURE (°C)
125
Figure 48. Latch Clamp Current vs. Junction
Temperature
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150
150
NCP1652, NCP1652A
100
VLATCH(shdn), LATCH−OFF CURRENT
SHUTDOWN (mA)
VLATCH(clamp), LATCH CLAMP
VOLTAGE (V)
3.5
3.4
3.3
3.2
3.1
3.0
−50
−25
0
25
50
75
100
125
150
98
96
94
92
90
−50
−25
0
25
50
75
100
125
TJ, JUNCTION TEMPERATURE (°C)
TJ, JUNCTION TEMPERATURE (°C)
Figure 49. Latch Clamp Voltage vs. Junction
Temperature
Figure 50. Latch−Off Current Shutdown vs.
Junction Temperature
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NCP1652, NCP1652A
DETAILED DEVICE DESCRIPTION
Introduction
designer familiarity and a vast range of available
components. But, because it processes the power twice, the
search is always on for a more compact and power efficient
solution.
The NCP1652 controller offers the convenience of
shrinking the front−end converter (PFC preregulator) and
the dc−dc converter into a single power processing stage as
shown in Figure 52.
The NCP1652 is a highly integrated controller combining
PFC and an isolated step down ac−dc power conversion in
a single stage, resulting in a lower cost and reduced part
count solution. This controller is ideal for notebook
adapters, battery chargers and other off−line applications
with power requirements between 75 W and 150 W with an
output voltage greater than 12 V. The single stage is based
on the flyback converter and it is designed to operate in CCM
or DCM modes.
AC
Input
Power Factor Correction (PFC) Introduction
Power factor correction shapes the input current of
off−line power supplies to maximize the real power
available from the mains. Ideally, the electrical appliance
should present a load that emulates a pure resistor, in which
case the reactive power drawn by the device is zero. Inherent
in this scenario is the freedom from input current harmonics.
The current is a perfect replica of the input voltage (usually
a sine wave) and is exactly in phase with it. In this case the
current drawn from the mains is at a minimum for the real
power required to perform the needed work, and this
minimizes losses and costs associated not only with the
distribution of the power, but also with the generation of the
power and the capital equipment involved in the process.
The freedom from harmonics also minimizes interference
with other devices being powered from the same source.
Another reason to employ PFC in many of today’s power
supplies is to comply with regulatory requirements. Today,
electrical equipment in Europe must comply with the
European Norm EN61000−3−2. This requirement applies to
most electrical appliances with input power of 75 W or
greater, and it specifies the maximum amplitude of
line−frequency harmonics up to and including the 39th
harmonic. While this requirement is not yet in place in the
US, power supply manufacturers attempting to sell products
worldwide are designing for compliance with this
requirement.
PFC
Preregulator
DC−DC
Converter
with isolator
Vout
This approach significantly reduces the component count.
The NCP1652 based solution requires only one each of
MOSFET, magnetic element, output rectifier (low voltage)
and output capacitor (low voltage). In contrast, the 2−stage
solution requires two or more of the above−listed
components. Elimination of certain high−voltage
components (e.g. high voltage capacitor and high voltage
PFC diode) has significant impact on the system design. The
resultant cost savings and reliability improvement are often
worth the effort of designing a new converter.
Single PFC Stage
While the single stage offers certain benefits, it is
important to recognize that it is not a recommended solution
for all requirements. The following three limitations apply
to the single stage approach:
• The output voltage ripple will have a 2x line frequency
component (120 Hz for North American applications)
that can not be eliminated easily. The cause of this
ripple is the elimination of the energy storage element
that is typically the boost output capacitor in the
2−stage solution. The only way to reduce the ripple is to
increase the output filter capacitance. The required
value of capacitance is inversely proportional to the
output voltage – hence this approach is not
recommended for low voltage outputs such as 3.3 V or
5 V. However, if there is a follow−on dc−dc converter
stage or a battery after the single stage converter, the
low frequency ripple should not cause any concerns.
• The hold−up time will not be as good as the 2−stage
approach – again due to the lack of an intermediate
energy storage element.
• In a single stage converter, one FET processes all the
power – that is both a benefit and a limitation as the
stress on that main MOSFET is relatively higher.
Similarly, the magnetic component (flyback
transformer/inductor) can not be optimized as well as in
A typical power supply consists of a boost PFC
preregulator creating an intermediate X400 V bus and an
isolated dc−dc converter producing the desired output
voltage as shown in Figure 51. This architecture has two
power stages.
Rectifier
&
Filter
NCP1652 Based
Single−Stage
Flyback Converter
Figure 52. Single Stage Power Converter
Typical Power Supply with PFC
AC
Input
Rectifier
&
Filter
Vout
Figure 51. Typical Two Stage Power Converter
A two stage architecture allows optimization of each
individual power stage. It is commonly used because of
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NCP1652, NCP1652A
the 2−stage solution. As a result, potentially higher
leakage inductance induces higher voltage spikes (like
the one shown in Figure 53) on the MOSFET drain.
This may require a MOSFET with a higher voltage
rating compared to similar dc−input flyback
applications.
Vin
Active
Clamp
Vout
Figure 56. Active Clamp
The first two methods result in dissipation of the leakage
energy in the clamping circuits – the dissipation is
proportional to LI2 where L is the leakage inductance of the
transformer and I is the peak of the switch current at
turn−off. An RDC snubber is simple and has the lowest cost,
but constantly dissipates power. A TVS provides good
voltage clamping at a slightly higher cost and dissipates
power only when the drain voltage exceeds the voltage
rating of the TVS.
The active clamp circuit provides an intriguing alternative
to the other methods. It requires addition of a MOSFET and
a high voltage capacitor as part of the active clamp circuit,
thus adding complexity, but it results in a complete reuse of
the leakage inductance energy. As a result, the transformer
construction is no longer critical and one can use cheaper
cost solution. Also, the active clamp circuit reduces the
voltage stress on the primary switch and that can lead to
usage of lower cost or lower on resistance (RDS(on))
MOSFET. Finally, the turn−on switching losses are
eliminated because the active clamp circuit allows the
discharge of the MOSFET COSS capacitance prior to the
turn−on. The energy stored in the leakage inductance is
utilized for this transition.
In many applications, the added complexity of the active
clamp circuit may not be justified. However, the OUTB of
the NCP1652 is also usable for another purpose,
synchronous
rectification
control.
Synchronous
rectification for flyback converters is an emerging
requirement for flyback converters. The OUTB signal from
NCP1652 is ideal for interfacing with a secondary side
synchronous rectifier controller such as NCP4303 as shown
in Figure 57. As shown in Figure 57, using the OUTB
(coupled through pulse transformer or Y−capacitor) as a
trigger for the NCP4303 allows guaranteed turn−off of the
secondary side synchronous MOSFET prior to turn−on of
the primary switch. In any CCM flyback converter, this is a
critical requirement to prevent cross−conduction and
NCP1652 and NCP4303 combination is the first such
chipset that guarantees the operation without
cross−conduction.
Figure 53. Typical Drain Voltage Waveform of a
Flyback Main Switch
There are a few methods to clamp the voltage spike on the
main switch, a resistor−capacitor−diode (RCD) clamp, a
transient voltage suppressor (TVS) or an active clamp using
a MOSFET and capacitor can be used as shown in
Figures 54 to 56.
RCD
Clamp
Vin
R
C
Vout
D
Figure 54. RCD Clamp
TVS
Clamp
Vin
Vout
TVS
Figure 55. TVS Clamp
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NCP1652, NCP1652A
VIN
VOUT
DRV
TRIG
NCP4303
OUTB
NCP1652
OUTA
Figure 57. NCP1652 and NCP4302 based single stage PFC with synchronous rectification.
compensation is also added to the input signal to allow CCM
operation above 50% duty cycle.
The NCP1652 incorporates a secondary driver, OUTB,
with adjustable non overlap delay for controlling a
synchronous rectifier switch in the secondary side, an active
clamp switch in the primary or both. In addition, the
controller features a proprietary Soft−Skip™ to reduce
acoustic noise at light loads. Other features found in the
NCP1652 include a high voltage startup circuit, voltage
feedforward, brown out detector, internal overload timer,
latch input and a high accuracy multiplier.
High Voltage Startup Circuit
The NCP1652 internal high voltage startup circuit
eliminates the need for external startup components and
provides a faster startup time compared to an external
startup resistor. The startup circuit consists of a constant
current source that supplies current from the HV pin to the
supply capacitor on the VCC pin (CCC). The startup current
(Istart) is typically 5.5 mA.
The OUTA and OUTB drivers are enabled and the startup
current source is disabled once the VCC voltage reaches
VCC(on), typically 15.3 V. The controller is then biased by
the VCC capacitor. The drivers are disabled if VCC decays to
its minimum operating threshold (VCC(off)) typically 10.3 V.
Upon reaching VCC(off) the gate drivers are disabled. The
VCC capacitor should be sized such VCC is kept above
VCC(off) while the auxiliary voltage is building up.
Otherwise, the system will not start.
The controller operates in double hiccup mode while in
overload or VCC(off). A double hiccup fault disables the
drivers, sets the controller in a low current mode and allows
VCC to discharge to VCC(off). This cycle is repeated twice to
minimize power dissipation in external components during
a fault event. Figure 58 shows double hiccup mode
operation. A soft−start sequence is initiated the second time
VCC reaches VCC(on). If the controller is latched upon
reaching VCC(on), the controller stays in hiccup mode.
During this mode, VCC never drops below VCC(reset), the
controller logic reset level. This prevents latched faults to be
cleared unless power to the controller is completely
removed (i.e. unplugging the supply from the AC line).
NCP1652 PFC Loop
The NCP1652 incorporates a modified version of average
current mode control used for achieving the unity power
factor. The PFC section includes a variable reference
generator, a low frequency voltage regulation error
amplifier (AC error AMP), ramp compensation (Ramp
Comp) and current shaping network. These blocks are
shown in the lower portion of the bock diagram (Figure 51).
The inputs to the reference generator include feedback
signal (FB), scaled AC input signal (AC_IN) and
feedforward input (VFF). The output of the reference
generator is a rectified version of the input sine−wave scaled
by the FB and VFF values. The reference amplitude is
proportional to the FB and inversely proportional to the
square of the VFF. This, for higher load levels and/or lower
input voltage, the signal would be higher.
The function of the AC error amp is to force the average
current output of the current sense amplifier to match the
reference generator output. The output of the AC error
amplifier is compensated to prevent response to fast events.
This output (Verror) is fed into the PWM comparator through
a reference buffer. The PWM comparator sums the Verror and
the instantaneous current and compares it to a 4.0 V
threshold to provide the desired duty cycle control. Ramp
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NCP1652, NCP1652A
VCC
VCC(on)
VCC(off)
t
OUTA
t
Fault Timer
(internal)
Overload
applied
t
tOVLD
Figure 58. VCC Double Hiccup Operation with a Fault Occurring while the Startup Circuit is Disabled
typically 0.85 V. Once VCC exceeds Vinhibit, the startup
current source is enabled. This behavior is illustrated in
Figure 59. This slightly increases the total time to charge
VCC, but it is generally not noticeable.
An internal supervisory circuit monitors the VCC voltage
to prevent the controller from dissipating excessive power
if the VCC pin is accidentally grounded. A lower level
current source (Iinhibit) charges CCC from 0 V to Vinhibit,
Figure 59. Startup Current at Various VCC Levels
the HV pin as shown in Figure 60. Otherwise, the HV pin
follows the ac line and the startup circuit is disabled every
time the ac line voltage approaches 0 V. The VCC capacitor
is sized to bias the controller during power up.
The rectified ac line voltage is provided to the power stage
to achieve accurate PFC. Filtering the rectified ac line
voltage with a large bulk capacitor distorts the PFC in a
single stage PFC converter. A peak charger is needed to bias
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NCP1652, NCP1652A
Peak Charger
VOUT
VIN
HV
OUTA
NCP1652
Figure 60. Peak charger
Adjustable Dead Time
The startup circuit is rated at a maximum voltage of 500 V.
Power dissipation should be controlled to avoid exceeding
the maximum power dissipation of the controller. If
dissipation on the controller is excessive, a resistor can be
placed in series with the HV pin. This will reduce power
dissipation on the controller and transfer it to the series
resistor.
OUTA and OUTB have an adjustable dead time between
transitions to prevent simultaneous conduction of the main
and synchronous rectifier or active clamp MOSFETs. The
delay is also used to optimize the turn−off transition of the
active clamp switch to achieve zero−volt switching of the
main switch in an active clamp topology. Figure 61 shows
the timing relationship between OUTA and OUTB.
Drive Outputs
The NCP1652 has out off phase output drivers with an
adjustable non−overlap delay (tD). The main output, OUTA,
drives the primary MOSFET. The secondary output, OUTB,
is designed to provide a logic signal used to control a
synchronous rectification switch in the secondary side, an
active clamp switch in the primary or both. The outputs are
biased directly from VCC and their high state voltage is
approximately VCC.
OUTA has a source resistance of 13 W (typical) and a sink
resistance of 8.0 W (typical) OUTB has a source resistance
22 W (typical) and a sink resistance of 10 W (typical). OUTB
is a purposely sized smaller than OUTA because the gate
charge of an active switch or logic used with synchronous
rectification is usually less than that of the primary
MOSFET. If a higher drive capability is required, an external
discrete driver can be used.
The drivers are enabled once VCC reaches VCC(on) and
there are no faults present. They are disabled once VCC
discharges to VCC(off). OUTB is always the last pulse
generated when the outputs are disabled due to a fault
(latch−off, VCC(off), overload, or brown−out). The last pulse
terminates at the end of the clock cycle. This ensures the
active clamp capacitor is reset.
The high current drive capability of OUTA and OUTB
may generate voltage spikes during switch transitions due to
parasitic board inductance. Shortening the connection
length between the drivers and their loads and using wider
connections will reduce inductance−induce spikes.
tdelay(lead)
tdelay(trail)
OUTA
OUTB
Figure 61. Timing relationship between OUTA and
OUTB.
The dead time between OUTA and OUTB is adjusted by
connecting a resistor, RD, from the RD pin to ground. The
overlap delay is proportional to RD. The delay time can be
set between 80 ns and 1.8 ms using the formula:
t delay(in ns) + 8.0
R delay(in kW) with
R delay varying between 10 kW and 230 kW
AC Error Amplifier and Buffer
The AC error amplifier (EA) shapes the input current into
a high quality sine wave by forcing the filtered input current
to follow the output of the reference generator. The output
of the reference generator is a full wave rectified ac signal
and it is applied to the non inverting input of the EA. The
filtered input current, Iin, is the current sense signal at the
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NCP1652, NCP1652A
ISpos pin multiplied by the current sense amplifier gain. It
is applied to the inverting input of the AC EA.
The AC EA is a transconductance amplifier. A
transconductance amplifier generates an output current
proportional to its differential input voltage. This amplifier
has a nominal gain of 100 mS (or 0.0001 A/V). That is, an
input voltage difference of 10 mV causes the output current
to change by 1.0 mA. The AC EA has typical source and sink
currents of 70 mA.
The filtered input current is a high frequency signal. A low
frequency pole forces the average input current to follow the
reference generator output. A pole-zero pair is created by
placing a (RCOMP) and capacitor (CCOMP) series
combination at the output of the AC EA. The AC COMP pin
provides access to the AC EA output.
The output of the AC EA is inverted and converted into a
current using a second transconductance amplifier. The
output of the inverting transconductance amplifier is
VACEA(buffer). Figure 62 shows the circuit schematic of the
AC EA buffer. The AC EA buffer output current, IACEA(out),
is given by Equation 1.
VDD
x4
IACEA(out)
+
+
−
2.8V
VAC_REF
21.33kW
+
IAVG
To PWM
comparator
37.33kW
gm = 100mS
gm
+
−
−
AC error
amplifier
RIAVG
AC COMP
RAC_COMP
Figure 62. AC EA Buffer Amplifier
I ACEA(out) +
ǒ
Ǔ
2.8 * V ACEA
37.33k
@4
amplifier is a wide bandwidth amplifier with a differential
input. The current sense amplifier has two outputs, PWM
Output and IAVG Output. The PWM Output is the
instantaneous switch current which is filtered by the internal
leading edge blanking (LEB) circuitry prior to applying it to
the PWM Comparator non inverting input. The second
output is a filtered current signal resembling the average
value of the input current. Figure 63 shows the internal
architecture of the current sense amplifier.
(eq. 1)
The voltage at the PWN non-inverting input is determined
by IACEA(out), the instantaneous switch current along and the
ramp compensation current. OUTA is terminated once the
voltage at the PWM non-inverting input reaches 4 V.
Current Sense Amplifier
A voltage proportional to the main switch current is
applied to the current sense input, ISPOS. The current sense
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NCP1652, NCP1652A
Ip
Ispos
gm = 250mS
+
−
RCS
blanking
gm
Current sense
amplifier
IAVG
Inst. current A
To PWM
tLEB
blanking
tLEB
VIAVG
comparator
Inst. current B
To PWM skip
comparator
To AC error
amplifier
RIAVG
Figure 63. Current Sense Amplifier
Caution should be exercised when designing a filter
between the current sense resistor and the ISPOS input, due
to the low impedance of this amplifier. Any series resistance
due to a filter creates a voltage offset (VOS) due to its input
bias current, CAIbias. The input bias current is typically
60 mA. The voltage offset is given by Equation 2.
V OS + CA Ibias @ R external
I CS + I IN +
V ISPOS
4k
(eq. 3)
The PWM Output delivers current to the positive input of
the PWM input where it is added to the AC EA and ramp
compensation signal.
The IAVG Output generates a voltage signal to a buffer
amplifier. This voltage signal is the product of IAVG and an
external RIAVG resistor filtered by the capacitor on the IAVG
pin, CIAVG. The pole frequency, fP, set by CIAVG should be
significantly below the switching frequency to remove the
high frequency content. But, high enough to not to cause
significant distortion to the input full wave rectified
sinewave waveform. A properly filtered average current
signal has twice the line frequency. Equation 4 shows the
relationship between CIAVG (in nF) and fP (in kHz).
(eq. 2)
The offset adds a positive offset to the current sense signal.
The ac error amplifier will then try to compensate for the
average output current which appears never to go to zero and
cause additional zero crossing distortion.
A voltage proportional to the main switch current is
applied to the ISPOS pin. The ISPOS pin voltage is converted
into a current, i1, and internally mirrored. Two internal
currents are generated, ICS and IAVG. ICS is a high frequency
signal which is a replica of the instantaneous switch current.
IAVG is a low frequency signal. The relationship between
VISPOS and ICS and IAVG is given by Equation 3.
C IAVG +
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1
2 @ p @ R IAVG @ f P
(eq. 4)
NCP1652, NCP1652A
Oscillator
The gain of the low frequency current buffer is set by the
resistor at the IAVG pin, RIAVG. RIAVG sets the scaling factor
between the primary peak and primary average currents.
The gain of the current sense amplifier, ACA, is given by
Equation 5.
A CA +
RI AVG
The oscillator controls the switching frequency, f, the jitter
frequency and the gain of the multiplier. The oscillator ramp
is generated by charging the timing capacitor on the CT Pin,
CT, with a 200 mA current source. This current source is
tightly controlled during manufacturing to achieve a
controlled and repeatable oscillator frequency. The current
source turns off and CT is immediately discharged with a
pull down transistor once the oscillator ramp reaches its peak
voltage, VCT(peak), typically 4.0 V. The pull down transistor
turns off and the charging current source turns on once the
oscillator ramp reaches its valley voltage, VCT(valley).
Figure 64 shows the resulting oscillator ramp and control
circuitry.
(eq. 5)
4k
The current sense signal is prone to leading edge spikes
during the main switch turn on due to parasitic capacitance
and inductance. This spike may cause incorrect operation of
the PWM Comparator. Filtering the current sense signal will
inevitably change the shape of the current pulse. The
NCP1652 incorporates LEB circuitry to block the first
200 ns (typical) of each current pulse. This removes the
leading edge spikes without altering the current signal
waveform.
VDD
x 1.2
To PWM
comparator
IAVG
To PWM skip
−
+
comparator
RIAVG
VDD
CT
+
CT
−
+
4.0 V / 0.1 V
Oscillator
Figure 64. Oscillator Ramp and Control Circuitry
The relationship between the oscillator frequency in kHz
and timing capacitor in pF is given by Equation 6.
CT +
47000
f
A low frequency oscillator modulates the switching
frequency, reducing the controller EMI signature and
allowing the use of a smaller EMI filter. The frequency
modulation or jitter is typically ±5% of the oscillator
frequency.
(eq. 6)
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NCP1652, NCP1652A
Output Overload
260 mV. A new Soft−Skip™ period starts once the voltage
on the AC−IN pin increases to 260 mV.
An increase in output load current terminates a
Soft−Skip™ event. A transient load detector terminates a
Soft−Skip™ period once VFB voltage exceeds VSSKIP by
more than 550 mV. This ensures the required output power
is delivered during a load transient and the output voltage
does not fall out of regulation. Figure 66 shows the
relationship between Soft−Skip™ and the transient load
detector.
The Feedback Voltage, VFB, is directly proportional to the
output power of the converter. An internal 6.7 kW resistor
pulls−up the FB voltage to the internal 6.5 V reference. An
external optocoupler pulls down the FB voltage to regulate
the output voltage of the system. The optocoupler is off
during power up and output overload conditions allowing
the FB voltage to reach its maximum level.
The NCP1652 monitors the FB voltage to detect an
overload condition. A typical startup time of a single PFC
stage converter is around 100 ms. If the converter is out of
regulation (FB voltage exceeds 5.0 V) for more that 150 ms
(typical) the drivers are disabled and the controller enters the
double hiccup mode to reduce the average power
dissipation. A new startup sequence is initiated after the
double hiccup is complete. This protection feature is critical
to reduce power during an output short condition.
Soft−Skip™ Cycle Mode
The FB voltage reduces as the output power demand of the
converter reduces. Once VFB drops below the skip
threshold, VSSKIP, 1.30 V (typical) the drivers are disabled.
The skip comparator hysteresis is typically 180 mV.
The converter output voltage starts to decay because no
additional output power is delivered. As the output voltage
decreases the feedback voltage increases to maintain the
output voltage in regulation. This mode of operation is
known as skip mode. The skip mode frequency is dependent
of load loop gain and output capacitance and can create
audible noise due to mechanical resonance in the
transformer and snubber capacitor. A proprietary
Soft−Skip™ mode reduces audible noise by slowly
increasing the primary peak current until it reaches its
maximum value. The minimum skip ramp period, tSSKIP, is
2.5 ms. Figure 65 shows the relationship between VFB,
VSSKIP and the primary current.
VSSKIP
VFB
Figure 66. Load transient during Soft−Skip]
The output of the Soft−Skip™ Comparator is or−ed with
the PWM Comparator output to control the duty ratio. The
Soft−Skip™ Comparator controls the duty ratio in skip
mode and the PWM Comparator controls the duty cycle
during normal operation. In skip mode, the non−inverting
input of the Soft−Skip™ Comparator exceeds 4 V, disabling
the drivers. As the FB voltage increases, the voltage at the
non−inverting input is ramp down from 4 V to 0.2 V to
enable the drivers.
Multiplier and Reference Generator
The NCP1652 uses a multiplier to regulate the average
output power of the converter. This controller uses a
proprietary concept for the multiplier used within the
reference generator. This innovative design allows greatly
improved accuracy compared to a conventional linear
analog multiplier. The multiplier uses a PWM switching
circuit to create a scalable output signal, with a very well
defined gain.
The output of the multiplier is the ac-reference signal. The
ac-reference signal is used to shape the input current. The
multiplier has three inputs, the error signal from an external
error amplifier (VFB), the full wave rectified ac input
(AC_IN) and the feedforward input (VFF).
The FB signal from an external error amplifier circuit is
applied to the VFB pin via an optocoupler or other isolation
circuit. The FB voltage is converted to a current with a V-I
Figure 65. Soft−Skip] operation.
Skip mode operation is synchronous of the ac line voltage.
The NCP1652 disables Soft−Skip™ when the rectified ac
line voltage drops to its valley level. This ensures the
primary current always ramp up reducing audible noise. A
skip event occurring as the ac line voltage is decreasing,
causes the primary peak current to ramp down instead of
ramp up. Once the skip period is over the primary current is
only determined by the ac line voltage. A Soft−Skip™ event
terminates once the AC−IN pin voltage decreases below
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NCP1652, NCP1652A
factored by the AC_IN comparator output. The resulting
signal is filtered by the low pass R-C filter on the CM pin.
The low pass filter removes the high frequency content. The
gain of the multiplier is determined by the V-I converter, the
resistor on the CM pin, and the peak and valley voltages of
the oscillator sawtooth ramp.
converter. There is no error in the output signal due to the
series rectifier as shown in Figure 67.
The scaled version of the full wave rectified input ac wave
is applied to the AC_IN pin by means of a resistive voltage
divider. The multiplier ramp is generated by comparing the
scaled line voltage to the oscillator ramp with the AC_IN
Comparator. The current signal from the V-I converter is
FB
Multiplier
V−to−I
+
AC IN
V
−
V
AC_REF
+k@
Oscillator
CM
FB
@V
V
AC_IN
FF
2
AC_REF
Divide
VFF2
VFF
Square
Figure 67. Reference Generator
The third input to the reference generator is the VFF signal.
The VFF signal is a dc voltage proportional to the ac line
voltage. A resistive voltage divider attenuates the full wave
rectified line voltage between 0.7 and 5.0 V. The full wave
rectified line is then averaged with a capacitor. The ac
average voltage must be constant over each half cycle of the
line. Line voltage ripple (120 Hz or 100 Hz) ripple on the
VFF signal adds ripple to the output of the multiplier. This
will distort the ac reference signal and reduce the power
factor and increase the line current distortion. Excessive
filtering delays the feedforward signal reducing the line
transient response. A good starting point is to set the filter
time constant to one cycle of the line voltage. The user can
then optimize the filter for line transient response versus
power factor. The average voltage on the VFF pin is:
V FF +
2
Vac Ǹ2a
p
V AC_REF +
V FB @ V AC_IN
V FF
2
@k
(eq. 8)
The multiplier transfer function is given by Equation 8.
The output of the multiplier is the AC_REF. It connects to
the AC Error Amplifier.
where, k is the reference generator gain, typically 0.55. The
output of the reference generator is clamped at 4.5 V to limit
the maximum output power.
Feedforward maintains a constant input power
independent of the line voltage. That is, for a given FB
voltage, if the line voltage doubles (AC_IN), the
feedforward term quadruples and reduces the output of the
error amplifier in half to maintain the same input power.
AC Error Amplifier Compensation
A pole-zero pair is created by placing a series combination
of RCOMP and CCOMP at the output of the AC error amplifier
(EA). The value of the compensation components is
(eq. 7)
Where, a is the voltage divider ratio, normally 0.01.
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NCP1652, NCP1652A
dependent of the average input current and the instantaneous
switch current. The gain of the average input current or slow
loop is given by Equation 9.
A LF +
ǒ Ǔ
R IAVG
4k
@ ǒgm @ R AC_COMPǓ @ (2.286)
where, Vin(LL) is the low line ac input voltage, D is the duty
ratio, Pout is the output power, Pin is the input power, h is the
efficiency, LP is the primary inductance and ton is the on
time. Typical efficiency for this topology is around 88%.
The current sense resistor is selected to achieve maximum
signal resolution at the input of the ac reference amplifier.
The maximum voltage input of the ac reference amplifier to
prevent saturation is 4.5 V. This together with the
instantaneous peak current is used to calculate the current
sense resistor, RCS, using Equation 16.
(eq. 9)
The low frequency gain is the product of the current sense
averaging circuit, the transconductance amplifier and the
gain of the AC error amplifier.
A current proportional to the instantaneous current is
generated using a 4 kW resistor in the current sense amplifier
input. This proportional current is applied to a 21.33 kW at
the PWM comparator input to generate a current sense
voltage signal. The high frequency or fast loop gain, AHF, is
calculated using Equation 10.
A HF +
21.33k
4k
+ 5.333
R CS + 4.5
R IAVG
4k
@ ǒgm @ R AC_COMPǓ @ (2.286) t
Subharmonic oscillations are observed in peak
current-mode controllers operating in continuous
conduction mode with a duty ratio greater than 50%.
Injecting a compensation ramp on the current sense signal
eliminates the subharmonic oscillations. The amount of
compensation is system dependent and it is determined by
the inductor falling di/dt.
The NCP1652 has built in ramp compensation to facilitate
system design. The amount of ramp compensation is set by
the user with a resistor, RRCOMP, between the Ramp Comp
pin and ground. The Ramp Comp pin buffers the oscillator
ramp generated on the CT pin. The current across RRCOMP
is internally mirrored with a 1:1.2 ratio. The inverted ac error
amplifier and the instantaneous switch current signals are
added to the ramp compensation mirrored current. The
resulting current signal is applied to an internal 21.33 kW
between the PWM Comparator non inverting input and
ground as shown in Figure 64.
The maximum voltage contribution of the ramp
compensation signal to the error signal, VRCOMP, is given by
Equation 17.
(eq. 10)
5.333
(eq. 11)
2
Equation 12 is obtained by re-arranging Equation 11 for
RAC_COMP. This equation provides the maximum value for
RAC_COMP.
R AC_COMP t
4666
R IAVG @ gm
(eq. 12)
The control loop zero, fZ, is calculated using Equation 13.
The control loop zero should be set at approximately at
1/10th of the oscillator frequency, fOSC. The compensation
capacitor is calculated using Equation 14.
fz +
1
2p @ C AC_COMP @ R AC_COMP
C AC_COMP +
1
2p @
f
OSC
10
(eq. 13)
(eq. 14)
@ R AC_COMP
V RCOMP +
Current Sense Resistor
Ǹ2 @ P
out
h @ V in(LL) @ D
)
V in(LL) @ t on
0.88 @ 2 @ L P
(1.2) @ ǒV CT(peak)Ǔ @ (21.33k)
R RCOMP
(eq. 17)
+
102.38k
R RCOMP
where, VCT(peak) is the oscillator ramp peak voltage,
typically 4.0 V.
For proper ramp compensation, the ramp signal should
match the falling di/dt (which has been converted to a dv/dt)
of the inductor at 50% duty cycle. Both the falling di/dt and
output voltage need to be reflected by the transformer turns
ratio to the primary side. Equations 18 through 23 assist in
the derivation of equations for RCS and RCOMP.
The PFC stage has two control loops. The first loop
controls the average input current and the second loop
controls the instantaneous current across the main switch.
The current sense signal affects both loops. The current
sense signal is fed into the positive input of the error
amplifier to control the average input current. In addition,
the current sense information together with the ramp
compensation and error amplifier signal control the
instantaneous primary peak current.
The primary peak current, IPK, is calculated using
Equation 15,
I PK +
(eq. 16)
R IAVG @ P in @ Ǹ2
Ramp Compensation
Equation 11 shows system stability requirements. That is,
the low frequency gain has to be less than one half of the high
frequency gain.
ǒ Ǔ
4k @ ǒV in(LL) @ DǓ
di
dt secondary
di
(eq. 15)
dt primary
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29
+
+
V out
LS
di
dt secondary
+
@
V out
LP
NS
NP
+
@
ǒ Ǔ
NP
NS
V out N P
LP NS
2
(eq. 18)
(eq. 19)
NCP1652, NCP1652A
di
V RCOMP +
NS
R CS +
NP
dt primary
@
@ T @ R CS @ A HF
L P @ 102.38k
T @ A HF @ V out @ R RCOMP
latch is Set dominant which means that if both R and S are
high the S signal will dominate and Q will be high, which
will hold the power switch off.
The NCP1652 uses a pulse width modulation scheme
based on a fixed frequency oscillator. The oscillator
generates a voltage ramp as well as a pulse in sync with the
falling edge of the ramp. The pulse is an input to the PWM
Logic and Driver block. While the oscillator pulse is present,
the latch is reset, and the output drive is in its low state. On
the falling edge of the pulse, the OUTA goes high and the
power switch begins conduction.
The instantaneous inductor current is summed with a
current proportional to the ac error amplifier output voltage.
This complex waveform is compared to the 4 V reference
signal on the PWM comparator inverting input. When the
signal at the non-inverting input to the PWM comparator
exceeds 4 V, the output of the PWM comparator toggles to
a high state which drives the Set input of the latch and turns
the power switch off until the next clock cycle.
(eq. 20)
(eq. 21)
At low line and full load, the output of the ac error
amplifier output is nearly saturated in a low state. While the
ac error amplifier output is saturated, IACEA is zero and does
not contribute to the voltage across the internal 21.33 kW
resistor on the PWM comparator non-inverting input. In this
operation mode, the voltage across the 21.33 kW resistor is
determined solely by the ramp compensation and the
instantaneous switch current as given by Equation 22.
ǒ
V ref(PWM) + V RCOMP @
Ǔ)V
t on
T
INST
(eq. 22)
The voltage reference of the PWM Comparator,
VREF(PWM), is 4 V. For these calculations, 3.8 V is used to
provide some margin. The maximum instantaneous switch
current voltage contribution, VINST, is given by
Equation 23.
V INST + I PK @ R CS @ A HF
Brown−Out
The NCP1652 incorporates a brown−out detection circuit
to prevent the controller operate at low ac line voltages and
reduce stress in power components. A scaled version of the
rectified line voltage is applied to the VFF Pin by means of
a resistor divider. This voltage is used by the brown out
detector.
A brown−out condition exists if the feedforward voltage
is below the brown−out exit threshold, VBO(high), typically
0.45 V. The brown−out detector has 180 mV hysteresis. The
controller is enabled once VFF is above 0.63 V and VCC
reaches VCC(on). OUTB is the last drive pulse. Figure 68
shows the relationship between the brown−out, VCC, OUTA
and OUTB signals.
(eq. 23)
Substituting Equation 23 in Equation 22, setting
VREF(PWM) at 3.8 V (provides margin) and solving for
RRCOMP, Equation 24 is obtained.
R RCOMP +
102.38k
ǒ3.8 * 5.333 @ IPK @ R CSǓ
@
t on
T
(eq. 24)
Replacing Equation 24 in Equation 21 we obtain:
R CS +
ǒ
3.8
N
P
N
S
@
A
@V
HF
L
Ǔ ) 5.333 I
out@ton
P
(eq. 25)
PK
PWM Logic
The PWM and logic circuits are comprised of a PWM
comparator, an RS flip-flop (latch) and an OR gate. The
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NCP1652, NCP1652A
VCC
VCC(on)
VCC(off)
t
OUTA
t
Last OUTB Pulase
OUTB
t
VFF
VBO(low)
VBO(high)
Brown−Out
t
Figure 68. Relationship Between the Brown−Out, VCC, OUTA and OUTB
Vaux or VCC
VDD
OVP comparator
+
−
+
Vlatch(high)
Ilatch(clamp)
blanking
tlatch(delay)
Latch−Off
OTP comparator
−
I latch(shdn)
S
Q
+
+
Latch
R
Vlatch(low)
NTC
Vlatch(clamp)
Reset
Figure 69.
Latch Input
Once the controller is latched, OUTA is disabled and OUTB
generates a final pulse that ends with the oscillator period.
No more pulses are generated after OUTB is terminated.
Figure 70 shows the relationship between the Latch−Off,
VCC, OUTA and OUTB signals.
The NCP1652 has a dedicated latch input to easily latch
the controller during overtemperature and overvoltage
faults (See Figure 69). The controller is latched if the
Latch−Off pin voltage is pulled below 1 V or above 6.5 V.
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NCP1652, NCP1652A
VCC
VCC(on)
VCC(off)
t
OUTA
t
Last OUTB Pulase
OUTB
t
Latch−Off
Vlatch(high)
Latch−Off
Vlatch(low)
Latch−Off
t
Figure 70. Relationship Between the Latch−Off, VCC, OUTA and OUTB
The Latch−Off pin is clamped at 3.5 V. A 50 mA (typical)
pull−up current source is always on and a 100 mA (typical)
pull−down current source is enabled once the Latch−Off pin
voltage reaches 3.5 V (typical). This effectively clamps the
Latch−Off pin voltage at 3.5 V. A minimum pull−up or
pull−down current of 50 mA is required to overcome the
internal current sources and latch the controller. The
Latch−Off input features a 50 ms (typical) filter to prevent
latching the controller due to noise or a line surge event.
The startup circuit continues to cycle VCC between
VCC(on) and VCC(off) while the controller is in latch mode.
The controller exits the latch mode once power to the system
is removed and VCC drops below VCC(reset).
APPLICATION INFORMATION
The electronic design tool allows the user to easily
determine most of the system parameters of a single PFC
stage The tool evaluates the power stage as well as the
frequency response of the system.
ON Semiconductor provides an electronic design tool,
facilitate design of the NCP1652 and reduce development
cycle time. The design tool can be downloaded at
www.onsemi.com.
ORDERING INFORMATION
Package
Shipping†
NCP1652DWR2G
SO−20 WB
(Pb−Free)
1000 / Tape & Reel
NCP1652DR2G
SO−16
(Pb−Free)
2500 / Tape & Reel
NCP1652ADR2G
SO−16
(Pb−Free)
2500 / Tape & Reel
Device
†For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging
Specifications Brochure, BRD8011/D.
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32
NCP1652, NCP1652A
PACKAGE DIMENSIONS
SO−20 WB
CASE 751D−05
ISSUE G
A
20
q
X 45 _
E
h
1
10
20X
B
B
0.25
M
T A
S
B
S
A
L
H
M
10X
0.25
NOTES:
1. DIMENSIONS ARE IN MILLIMETERS.
2. INTERPRET DIMENSIONS AND TOLERANCES
PER ASME Y14.5M, 1994.
3. DIMENSIONS D AND E DO NOT INCLUDE MOLD
PROTRUSION.
4. MAXIMUM MOLD PROTRUSION 0.15 PER SIDE.
5. DIMENSION B DOES NOT INCLUDE DAMBAR
PROTRUSION. ALLOWABLE PROTRUSION
SHALL BE 0.13 TOTAL IN EXCESS OF B
DIMENSION AT MAXIMUM MATERIAL
CONDITION.
11
B
M
D
18X
e
A1
SEATING
PLANE
C
T
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33
DIM
A
A1
B
C
D
E
e
H
h
L
q
MILLIMETERS
MIN
MAX
2.35
2.65
0.10
0.25
0.35
0.49
0.23
0.32
12.65
12.95
7.40
7.60
1.27 BSC
10.05
10.55
0.25
0.75
0.50
0.90
0_
7_
NCP1652, NCP1652A
PACKAGE DIMENSIONS
SOIC−16
CASE 751B−05
ISSUE K
−A−
16
NOTES:
1. DIMENSIONING AND TOLERANCING PER ANSI
Y14.5M, 1982.
2. CONTROLLING DIMENSION: MILLIMETER.
3. DIMENSIONS A AND B DO NOT INCLUDE MOLD
PROTRUSION.
4. MAXIMUM MOLD PROTRUSION 0.15 (0.006) PER SIDE.
5. DIMENSION D DOES NOT INCLUDE DAMBAR
PROTRUSION. ALLOWABLE DAMBAR PROTRUSION
SHALL BE 0.127 (0.005) TOTAL IN EXCESS OF THE D
DIMENSION AT MAXIMUM MATERIAL CONDITION.
9
−B−
1
P
8 PL
0.25 (0.010)
8
B
M
S
G
R
K
F
X 45 _
C
−T−
SEATING
PLANE
J
M
D
DIM
A
B
C
D
F
G
J
K
M
P
R
MILLIMETERS
MIN
MAX
9.80
10.00
3.80
4.00
1.35
1.75
0.35
0.49
0.40
1.25
1.27 BSC
0.19
0.25
0.10
0.25
0_
7_
5.80
6.20
0.25
0.50
INCHES
MIN
MAX
0.386
0.393
0.150
0.157
0.054
0.068
0.014
0.019
0.016
0.049
0.050 BSC
0.008
0.009
0.004
0.009
0_
7_
0.229
0.244
0.010
0.019
16 PL
0.25 (0.010)
M
T B
S
A
S
SOLDERING FOOTPRINT
8X
6.40
16X
1.12
1
16
16X
0.58
1.27
PITCH
8
9
DIMENSIONS: MILLIMETERS
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NCP1652/D