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Электронный компонент: FAN7528N

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2005 Fairchild Semiconductor Corporation
1
www.fairchildsemi.com
December 2005
FAN7528 Rev. 1.0.1
F
A
N7528 Dual Output Critical
Condu
ction Mode PF
C Contro
ller
FAN7528
Dual Output Critical Conduction Mode PFC Controller
Features
Low Total Harmonic Distortion (THD)
Dual Output Voltage Control
Precise Adjustable Output Over Voltage Protection
Open-feedback Protection and Disable Function
Zero Current Detector
160us Internal Start-up Timer
MOSFET Over Current Protection
Under Voltage Lock Out with 3.5V Hysteresis
Low Start-up (40uA) and Operating Current (1.5mA)
Totem Pole Output with High State Clamp
400mA Peak Gate Drive Current
8-pin DIP or 8-pin SOP
Applications
Adapter
Related Application Notes
AN6012 - Design of Power Factor Correction Circuit Using
FAN7528
Description
The FAN7528 is an active power factor correction (PFC) con-
troller for boost PFC applications which operates in the critical
conduction mode (CRM). It uses the voltage mode PWM that
compares an internal ramp signal with the error amplifier output
to generate MOSFET turn-off signal. Because the voltage mode
CRM PFC controller does not need the rectified AC line voltage
information, it can save the power loss of the input voltage sens-
ing network that is necessary for the current mode CRM PFC
controller.
The FAN7528 provides the dual output voltage control function
without the AC line voltage sensing for adapter applications. It
changes the PFC output voltage according to the AC line volt-
age.
It provides many protection functions such as over voltage pro-
tection, open-feedback protection, over current protection and
under voltage lock out protection. The FAN7528 can be dis-
abled if the INV pin voltage is lower than 0.45V and then the
operating current decreases to 65uA. Using a new variable on-
time control method, THD is lower than the conventional CRM
boost PFC ICs.
Ordering Information
Part Number
Operating Temp.
Range
Pb-Free
Package Packing
Method
Marking
Code
FAN7528N
-40
C to +125
C
Yes
8-DIP
Rail
FAN7528
FAN7528M
-40
C to +125
C
Yes
8-SOP
Rail
FAN7528
FAN7528MX
-40
C to +125
C
Yes
8-SOP
Tape & Reel
FAN7528
2
www.fairchildsemi.com
FAN7528 Rev. 1.0.1
F
A
N7528 Dual Outp
ut Critical
Co
nduction Mode PFC Con
t
roller
Typical Application Diagrams
Figure 1. Typical Boost PFC Application
Internal Block Diagram
Figure 2. Functional Block Diagram of FAN7528
GND
ZCD
INV
Vcc
AC
In
Vo
COMP
FAN7528
CS
MOT
R1
R2
L
D
Co
N
AUX
V
AUX
R
ZCD
INV
Error
Amp
OVP
COMP
8pF
40k
2.5V
Ref
Internal
Bias
160us
Timer
Vcc
ZCD
CS
UVLO
6.7V
12V
8.5V
2.66V
2.55V
OCP
Comparator
1V
MOT
GND
Saw Tooth
Generator
Zero Current
Detector
R
S
Q
3
6
4
5
2
1
8
Dual Output Reference
Generator
1.5V/2.5V
Gm
Vref
0.8V
Disable
0.45V 0.35V
Disable
1.5V
1.4V
7
Vcc
OUT
Drive
Output
3
www.fairchildsemi.com
FAN7528 Rev. 1.0.1
F
A
N7528 Dual Outp
ut Critical
Co
nduction Mode PFC Con
t
roller
Pin Assignments
Figure 3. Pin Configuration (Top View)
Pin Definitions
Pin Number Pin Name
Pin Function Description
1
INV
This pin is the inverting input of the error amplifier. The output voltage of the boost PFC converter
should be resistively divided to 2.5V at the high line condition and connected to this pin. If this
pin voltage is controlled to be lower than 0.45V, the device is disabled.
2
COMP
This pin is the output of the transconductance error amplifier. Some components for the output
voltage compensation should be connected between this pin and GND.
3
MOT
This pin is used to set the slope of the internal ramp. The voltage of this pin is maintained to be
1V. If a resistor is connected between this pin and GND, current flows out of the pin and the slope
of the internal ramp is proportional to this current.
4
CS
This pin is the input of the over current protection comparator. The MOSFET current is sensed
using a sensing resistor and the resulting voltage is applied to this pin. An internal RC filter is
included to filter switching noise. This pin is sensitive to the negative voltage below -0.3V. For
proper operation, the stray inductance in the sensing path and the inductance of the sensing re-
sistor must be minimized.
5
ZCD
This pin is the input of the zero current detection block. If the voltage of this pin goes higher than
1.5V and then goes lower than 1.4V, the MOSFET is turned on.
6
GND
This pin is used for the ground potential of all the pins. For proper operation, the signal ground
and the power ground should be separated.
7
OUT
This pin is the gate drive output. The peak sourcing and sinking current level is 400mA. For prop-
er operation, the stray inductance in the gate driving path must be minimized.
8
Vcc
This pin is the IC supply pin. IC current and MOSFET drive current are supplied using this pin.
F A N
7 5 2 8
6
5
8
7
Vcc
OUT
GND
ZCD
1
2
3
4
COMP
CS
MOT
INV
W W W
4
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FAN7528 Rev. 1.0.1
F
A
N7528 Dual Outp
ut Critical
Co
nduction Mode PFC Con
t
roller
Absolute Maximum Ratings
(Ta=25
C, unless otherwise specified)
Thermal Impedance
Note:
1. Regarding the test environment and PCB type, please refer to JESD51-2 and JESD51-10.
Parameter
Symbol
Value
Unit
Supply Voltage
Vcc
23
V
Peak Drive Output Current
I
OH
, I
OL
400
mA
Driver Output Clamping Diodes Vo>Vcc or Vo<-0.3V
Iclamp
10
mA
Detector Clamping Diodes
Idet
10
mA
Error Amp, MOT, CS Input Voltages
Vin
-0.3 to 6
V
Operating Junction Temperature
Tj
150
C
Operating Temperature Range
Topr
-40 to 125
C
Storage Temperature Range
Tstg
-65 to 150
C
ESD Capability, HBM Model
(All pins except Vcc)
-
2.0
kV
ESD Capability, Machine Model
-
300
V
Parameter
Symbol
Value
Unit
Thermal Resistance, Junction to Ambient
8-DIP
R
ja
110
C/W
8-SOP
150
C/W
5
www.fairchildsemi.com
FAN7528 Rev. 1.0.1
F
A
N7528 Dual Outp
ut Critical
Co
nduction Mode PFC Con
t
roller
Electrical Characteristics
(Vcc = 14V, Ta = -40
C~125
C, unless otherwise specified)
Parameter Symbol
Condition
Min.
Typ.
Max.
Unit
UNDER VOLTAGE LOCK OUT SECTION
Start Threshold Voltage
Vth(start)
Vcc increasing
11
12
13
V
Stop Threshold Voltage
Vth(stop)
Vcc decreasing
8
8.5
9
V
UVLO Hysteresis
HY(uvlo)
-
3
3.5
4
V
SUPPLY CURRENT SECTION
Start-up Supply Current
Ist
Vcc = Vth(start) - 0.2V
-
40
70
A
Operating Supply Current
Icc
Output no switching
-
1.5
3
mA
Dynamic Operating Supply Current
Idcc
50kHz, Cl=1nF
-
2.5
4
mA
Operating Current at Disable
Icc(dis)
Vinv = 0V
40
65
90
A
ERROR AMPLIFIER SECTION
Voltage Feedback Input Threshold1
Vref1
Ta = 25
C
2.465
2.5
2.535
V
-
2.435
2.5
2.565
V
Voltage Feedback Input Threshold2
Vref2
-
1.45
1.5
1.55
V
Line Regulation
V
ref1
Vcc = 14V ~ 23V
-
0.1
10
mV
Temperature Stability of Vref1
(1)
V
ref3
-
-
20
-
mV
Input Bias Current
Ib(ea)
Vinv = 1V ~ 4V
-0.5
-
0.5
A
Output Source Current
Isource
Vinv = 2.4V
-
-12
-
A
Output Sink Current
Isink
Vinv = 2.6V
-
12
-
A
Output Upper Clamp Voltage
Veao(H)
-
4.5
5.5
6.5
V
Zero Duty Cycle Output Voltage
Veao(Z)
-
0.7
1
1.3
V
Transconductance
(1)
gm
-
90
115
140
mho
Output Voltage Selection Threshold
Vth(in)
Ta = 25
C
1.24
1.3
1.36
V
Output Voltage Reset Threshold
(1)
Vth(reset)
-
3
4.5
6
V
MAXIMUM ON-TIME SECTION
Maximum On-time Voltage
Vmot
Rmot = 13.7k
0.95
1
1.05
V
Maximum On-time Programming
Ton-max
Rmot = 13.7k, Ta = 25
C
18
22.5
27
A
CURRENT SENSE SECTION
Current Sense Input Threshold Voltage
Limit
Vcs(limit)
-
0.7
0.8
0.9
V
Input Bias Current
Ib(cs)
Vcs = 0V ~ 1V
-1
-0.1
1
A
Current Sense Delay to Output
(1)
Td(cs)
-
-
350
500
ns
6
www.fairchildsemi.com
FAN7528 Rev. 1.0.1
F
A
N7528 Dual Outp
ut Critical
Co
nduction Mode PFC Con
t
roller
Electrical Characteristics (Continued)
(Vcc = 14V, Ta = -40
C~125
C, unless otherwise specified)
Note:
1. These parameters, although guaranteed by design, are not tested in mass production.
Parameter Symbol
Condition
Min.
Typ.
Max.
Unit
ZERO CURRENT DETECT SECTION
Input Voltage Threshold
(1)
Vth
(ZCD)
-
1.35
1.5
1.65
V
Detect Hysteresis
(1)
HY
(ZCD)
-
0.05
0.1
0.15
V
Input High Clamp Voltage
Vclamp(h)
Idet = 3mA
6
6.7
7.4
V
Input Low Clamp Voltage
Vclamp(l)
Idet = -3mA
0
0.6
1
V
Input Bias Current
Ib
(ZCD)
V
ZCD
= 1V ~ 5V
-1
-0.1
1
A
Source Current Capability
(1)
Isource(zcd)
-
-
-
-10
mA
Sink Current Capability
(1)
Isink(zcd)
-
-
-
10
mA
Maximum Delay from ZCD to Output
Turn-on
(1)
Tdead
-
100
-
200
ns
OUTPUT SECTION
Output Voltage High
Voh
Io = -100mA
9.2
11
12.8
V
Output Voltage Low
Vol
Io = 100mA
-
1
2.5
V
Rising Time
(1)
Tr
Cl = 1nF
-
50
100
ns
Falling Time
(1)
Tf
Cl = 1nF
-
50
100
ns
Maximum Output Voltage
Vo(max)
Vcc = 20V, Io = 100
A
11.5
13
14.5
V
Output Voltage with UVLO Activated
Vo(uvlo)
Vcc = 5V, Io = 100
A
-
-
1
V
RESTART TIMER SECTION
Restart Timer Delay
td(rst)
-
40
160
360
s
OVER VOLTAGE PROTECTION SECTION
OVP Threshold Voltage
Vovp
Ta = 25
C
2.6
2.66
2.72
V
OVP Hysteresis
HY(ovp)
-
0.06
0.11
0.16
V
ENABLE SECTION
Enable Threshold Voltage
Vth(en)
-
0.4
0.45
0.5
V
Enable Hysteresis
HY(en)
-
0.05
0.1
0.15
V
7
www.fairchildsemi.com
FAN7528 Rev. 1.0.1
F
A
N7528 Dual Outp
ut Critical
Co
nduction Mode PFC Con
t
roller
Typical Performance Characteristics
Figure 4. Start Threshold Voltage vs. Temp.
Figure 6. UVLO Hysteresis vs. Temp.
Figure 8. Operating Supply Current vs. Temp.
Figure 5. Stop Threshold Voltage vs. Temp.
Figure 7. Start-up Supply Current vs. Temp.
Figure 9. Dynamic Operating Current vs. Temp.
-60
-40
-20
0
20
40
60
80
100
120
140
11.2
11.6
12.0
12.4
12.8
V
t
h
(
s
t
a
r
t)[V
]
Temperature[
]
Start Threshold Voltage
-60
-40
-20
0
20
40
60
80
100
120
140
3.0
3.2
3.4
3.6
3.8
4.0
HY
(uvl
o
)
[
V
]
Temperature[
]
UVLO Hysteresis
-60
-40
-20
0
20
40
60
80
100
120
140
0.0
0.5
1.0
1.5
2.0
2.5
3.0
Icc[mA]
Temperature[
]
Operating Supply Current
-60
-40
-20
0
20
40
60
80
100
120
140
7.6
8.0
8.4
8.8
9.2
Vt
h(
stop)[
V
]
Temperature[
]
Stop Threshold Voltage
-60
-40
-20
0
20
40
60
80
100
120
140
0
10
20
30
40
50
60
70
Is
t
[
u
A
]
Temperature[
]
Start-up Supply Current
-60
-40
-20
0
20
40
60
80
100
120
140
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
Id
c
c
[mA
]
Temperature[
]
Dynamic Operating Supply Current
8
www.fairchildsemi.com
FAN7528 Rev. 1.0.1
F
A
N7528 Dual Outp
ut Critical
Co
nduction Mode PFC Con
t
roller
Typical Performance Characteristics (Continued)
Figure 10. Icc at Disable vs. Temp.
Figure 12. Vref2 vs. Temp.
Figure 14. Error Amp. Source Current vs. Temp.
Figure 11. Vref1 vs. Temp.
Figure 13. Input Bias Current vs. Temp.
Figure 15. Error Amp. Sink Current vs. Temp.
-60
-40
-20
0
20
40
60
80
100
120
140
40
50
60
70
80
90
Icc(
di
s)
[
u
A
]
Temperature[
]
Operating Current at Disable
-60
-40
-20
0
20
40
60
80
100
120
140
1.46
1.48
1.50
1.52
1.54
Vre
f
2
[
V]
Temperature[
]
Voltage Feedback Input Threshold2
-60
-40
-20
0
20
40
60
80
100
120
140
-18
-15
-12
-9
-6
I
s
ource[
uA]
Temperature[
]
Output Source Current
-60
-40
-20
0
20
40
60
80
100
120
140
2.44
2.46
2.48
2.50
2.52
2.54
2.56
Vr
e
f
1[
V]
Temperature[
]
Voltage Feedback Input Threshold1
-60
-40
-20
0
20
40
60
80
100
120
140
-0.4
-0.2
0.0
0.2
0.4
I
b
(
ea)
[uA]
Temperature[
]
Input Bias Current
-60
-40
-20
0
20
40
60
80
100
120
140
6
9
12
15
18
Is
in
k
[
u
A
]
Temperature[
]
Output Sink Current
9
www.fairchildsemi.com
FAN7528 Rev. 1.0.1
F
A
N7528 Dual Outp
ut Critical
Co
nduction Mode PFC Con
t
roller
Typical Performance Characteristics (Continued)
Figure 16. Error Amp. Clamp Voltage vs. Temp.
Figure 18. Output Select Threshold vs. Temp.
Figure 20. Maximum On-time vs. Temp.
Figure 17. Zero Duty Output Voltage vs. Temp.
Figure 19. MOT pin Voltage vs. Temp.
Figure 21. Current Limit vs. Temp.
-60
-40
-20
0
20
40
60
80
100
120
140
4.5
5.0
5.5
6.0
6.5
Ve
a
o
(H
)[V
]
Temperature[
]
Output Upper Clamp Voltage
-60
-40
-20
0
20
40
60
80
100
120
140
1.24
1.26
1.28
1.30
1.32
1.34
1.36
V
t
h
(
in
)[V
]
Temperature[
]
Output Voltage Selection Threshold
-60
-40
-20
0
20
40
60
80
100
120
140
18
20
22
24
26
To
n-
m
ax[
us]
Temperature[
]
Maximum On-Time Programming
-60
-40
-20
0
20
40
60
80
100
120
140
0.7
0.8
0.9
1.0
1.1
1.2
1.3
Ve
a
o
(Z
)[
V]
Temperature[
]
Zero Duty Cycle Output Voltage
-60
-40
-20
0
20
40
60
80
100
120
140
0.96
0.98
1.00
1.02
1.04
Vm
o
t
[
V
]
Temperature[
]
Maximum On-Time Voltage
-60
-40
-20
0
20
40
60
80
100
120
140
0.72
0.76
0.80
0.84
0.88
V
c
s
(
lim
it)[
V]
Temperature[
]
Current Sense Input Threshold Voltage
10
www.fairchildsemi.com
FAN7528 Rev. 1.0.1
F
A
N7528 Dual Outp
ut Critical
Co
nduction Mode PFC Con
t
roller
Typical Performance Characteristics (Continued)
Figure 22. CS Input Bias Current vs. Temp.
Figure 24. ZCD Input Low Clamp vs. Temp.
Figure 26. Output Voltage High vs. Temp.
Figure 23. ZCD Input High Clamp vs. Temp.
Figure 25. ZCD Input Bias Current vs. Temp.
Figure 27. Output Voltage Low vs. Temp.
-60
-40
-20
0
20
40
60
80
100
120
140
-0.9
-0.6
-0.3
0.0
0.3
0.6
0.9
I
b
(
cs)
[uA]
Temperature[
]
Input Bias Current
-60
-40
-20
0
20
40
60
80
100
120
140
0.0
0.2
0.4
0.6
0.8
1.0
Vc
l
a
mp
(
l
)[V
]
Temperature[
]
Input Low Clamp Voltage
-60
-40
-20
0
20
40
60
80
100
120
140
9.5
10.0
10.5
11.0
11.5
12.0
12.5
Voh
[
V]
Temperature[
]
Output Voltage High
-60
-40
-20
0
20
40
60
80
100
120
140
6.0
6.2
6.4
6.6
6.8
7.0
7.2
7.4
V
c
la
mp
(h
)[V
]
Temperature[
]
Input High Clamp Voltage
-60
-40
-20
0
20
40
60
80
100
120
140
-0.8
-0.4
0.0
0.4
0.8
I
b
(
Z
CD)
[uA]
Temperature[
]
Input Bias Current
-60
-40
-20
0
20
40
60
80
100
120
140
0.0
0.5
1.0
1.5
2.0
2.5
Vo
l[V
]
Temperature[
]
Output Voltage Low
11
www.fairchildsemi.com
FAN7528 Rev. 1.0.1
F
A
N7528 Dual Outp
ut Critical
Co
nduction Mode PFC Con
t
roller
Typical Performance Characteristics (Continued)
Figure 28. Maximum Output Voltage vs. Temp.
Figure 30. Restart Timer Delay vs. Temp.
Figure 32. OVP Hysteresis vs. Temp.
Figure 29. Output Voltage when UVLO vs. Temp.
Figure 31. Over Voltage Protection vs. Temp.
Figure 33. Enable Threshold Voltage vs. Temp.
-60
-40
-20
0
20
40
60
80
100
120
140
11.5
12.0
12.5
13.0
13.5
14.0
14.5
V
o
(
m
a
x
)[V
]
Temperature[
]
Maximum Ouput Voltage
-60
-40
-20
0
20
40
60
80
100
120
140
50
100
150
200
250
300
350
400
Td
(
r
s
t
)
[
u
s
]
Temperature[
]
Restart Time Delay
-60
-40
-20
0
20
40
60
80
100
120
140
0.06
0.08
0.10
0.12
0.14
H
Y
(o
v
p
)[
V]
Temperature[
]
OVP Hysteresis
-60
-40
-20
0
20
40
60
80
100
120
140
0.0
0.2
0.4
0.6
0.8
1.0
V
o
(u
v
l
o
)[V
]
Temperature[
]
Output Voltage with UVLO Activated
-60
-40
-20
0
20
40
60
80
100
120
140
2.60
2.62
2.64
2.66
2.68
2.70
2.72
2.74
Vov
p
[V
]
Temperature[
]
OVP Threshold Voltage
-60
-40
-20
0
20
40
60
80
100
120
140
0.40
0.42
0.44
0.46
0.48
0.50
V
t
h
(
e
n
)[V
]
Temperature[
]
Enable Threshold Voltage
12
www.fairchildsemi.com
FAN7528 Rev. 1.0.1
F
A
N7528 Dual Outp
ut Critical
Co
nduction Mode PFC Con
t
roller
Typical Performance Characteristics (Continued)
Figure 34. Enable Hysteresis vs. Temp.
-60
-40
-20
0
20
40
60
80
100
120
140
0.06
0.08
0.10
0.12
0.14
H
Y
(e
n
)[V
]
Temperature[
]
Enable Hysteresis
13
www.fairchildsemi.com
FAN7528 Rev. 1.0.1
F
A
N7528 Dual Outp
ut Critical
Co
nduction Mode PFC Con
t
roller
Applications Information
1. Error Amplifier Block
The error amplifier block has several functions such as dual out-
put function, over voltage protection function and disable func-
tion.
1.1 Dual Output Function
Unlike conventional CRM PFC controllers, the FAN7528 has the
dual output control function according to the AC line voltage
without sensing the rectified AC line voltage. Because the out-
put voltage of the boost converter is proportional to the peak
voltage of the input AC line voltage before the boost converter
starts switching, the INV pin voltage represents the peak AC line
voltage. When the AC line is connected to the boost converter,
Vcc voltage starts to increase from zero voltage. If the Vcc volt-
age reaches 8.5V, the dual output reference generator com-
pares the INV pin voltage with 1.3V reference and if the INV pin
voltage is lower than 1.3V the dual output reference generator
sets the reference voltage of the error amplifier to be 1.5V. If the
INV pin voltage is higher than 1.3V, the reference voltage is set
to be 2.5V. That means if the output voltage of the boost con-
verter is set to be 400V at high line, the output voltage is
240V(400V*1.5/2.5) at low line. If the output voltage is set to be
390V at high line, the output voltage is 234V at low line.
Because this block does not need the input voltage sensing net-
work, the power loss and cost related with the sensing network
can be saved. The reference voltage of the error amplifier is not
reset until the Vcc voltage goes below 4.5V.
Figure 35. Error amplifier block
1.2 Over Voltage Protection Function
The control speed of the PFC converter is very slow, therefore
the over voltage protection of the output voltage is very impor-
tant. The FAN7528 provides a precise OVP function that shuts
down the drive circuit when the INV pin voltage exceeds 2.66V,.
and there is 0.11V hysteresis.
1.3 Disable Function
If the INV pin voltage is lower than 0.45V, most of the internal
block is disabled and the operating current is reduced to be
65uA, and there is 0.1V hysteresis in the comparator.
1.4 Error Amplifier
The error amplifier is a transconductance type amplifier. The
output current of the amplifier is proportional to the voltage dif-
ference between the inverting input and the non inverting input
of the amplifier. Some resistors and capacitors should be con-
nected to the error amplifier output pin, the COMP pin, for the
output voltage loop compensation.
2. Zero Current Detection Block
The zero current detector(ZCD) generates the turn-on signal of
the MOSFET when the boost inductor current reaches zero
using an auxiliary winding coupled with the inductor. If the volt-
age of the ZCD pin goes higher than 1.5V then the ZCD com-
parator waits until the voltage goes below 1.4V. If the voltage
goes below 1.4V, the zero current detector turns on the MOS-
FET. The ZCD pin is protected internally by two clamps, 6.7V
high clamp and 0.6V low clamp. The 160us timer generates a
MOSFET turn-on signal if the drive output has been low for
more than 160us from the falling edge of the drive output.
Figure 36. Zero current detector block
3. Saw Tooth Generator Block
The output of the error amplifier and the output of the saw tooth
generator are compared to determine the MOSFET turn-off
instance. The slope of the saw tooth is determined by an exter-
nal resistor connected to the MOT pin. The voltage of the MOT
pin is 1V and the slope is proportional to the current flowing out
of the MOT pin. The internal ramp signal has 1V offset, there-
fore the drive output is shut down if the voltage of the COMP pin
is lower than 1V. The MOSFET on-time is maximum when the
COMP pin voltage is 5V. According to the slope of the internal
ramp, the maximum on-time can be programmed. The neces-
sary maximum on-time depends on the boost inductor, lowest
OVP
2.66V
2.55V
0.45V 0.35V
Disable
INV
Error
Amp
COMP
2
1
Gm
Dual Output
Reference
Generator
Vout
1.5V/2.5V
Timer
ZCD
6.7V
Zero Current
Detector
R
S
Q
5
1.5V
1.4V
Turn-on
Signal
Vin
R
ZCD
160us
14
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AC line voltage and maximum output power. The resistor value
should be designed properly.
Figure 37. Zero current detector block
4. Over Current Protection Block
The MOSFET current is sensed using an external sensing
resistor for the over current protection. If the CS pin voltage is
higher than 0.8V, the over current protection comparator gener-
ates a protection signal. An internal RC filter is included to filter
switching noise.
Figure 38. Over current protection block
5. Switch Drive Block
The FAN7528 contains a single totem-pole output stage
designed for a direct drive of power MOSFET. The drive output
is capable of up to 400mA peak current with a typical rise and
fall time of 50ns with 1nF load. The output voltage is clamped to
be 13V to protect MOSFET gate even if the Vcc voltage is
higher than 20V.
6. Under Voltage Lock Out Block
If the Vcc voltage reaches 12V, the IC's internal blocks are
enabled and start operation. If the Vcc voltage drops below
8.5V, most of the internal blocks are disabled to reduce the
operating current. Vcc voltage should be higher than 8.5V under
normal conditions.
1V
M O T
Saw T ooth
G enerator
3
E rror A m p
O utput
O ff Signal
1V
8pF
40k
CS
Over Current
Protection
Comparator
4
0.8V
OCP
Signal
15
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Typical application circuit
Features
High efficiency (>90% at 90Vac input)
Low THD(total harmonic distortion) (<10% at 264Vac input)
Dual output control
Key Design Notes
Diode D4 is used to prevent IC malfunction that can happen if the CS pin voltage is lower than -0.3V.
Important Component s for low THD are R2, R5 and C11.
1. Schematic
Figure 39. Schematic
Application
Output power
Input voltage
Output voltage
Adapter
100W
Universal input
(90~264Vac)
389V/232V
F1
AC INPUT
5
6
7
8
OU
T
Vc
c
GND
ZCD
IN
V
CO
MP
MOT
CS
FAN7528
1
2
3
4
V1
C1
C3 C4
LF1
C2
NTC
BD
C5
R1
C6
R3
R4
R5
T1
D1
C7
R7
R10
R6
R8
D2
R9
C8
Q1
V
AUX
R2
R11
C9
ZD1
C10
PFC OUTPUT
D3
D4
C11
16
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2. Inductor Schematic Diagram
Figure 40. Inductor Schematic Diagram
3.Winding Specification
4.Electrical Characteristics
5. Core & Bobbin
Core : EI 3026
Bobbin : EI3026
Ae(mm2) : 111
No
Pin (s
f)
Wire
Turns
Winding Method
N
Vcc
2
1
0.2
1
5
Solenoid Winding
Insulation: Polyester Tape t = 0.050mm, 4Layers
Np
5
3
0.2
10
44
Solenoid Winding
Outer Insulation: Polyester Tape t = 0.050mm, 4Layers
Air Gap: 0.6mm for each leg
Pin
Specification
Remarks
Inductance
3 - 5
400uH 10%
100kHz, 1V
Np
1
2
N
Vcc
5
3
17
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6.Demo Circuit Part List
Part
Value
Note
Part
Value
Note
Fuse
Inductor
F1
3A/250V
T1
400uH
EI3026
NTC
NTC
10D-9
MOSFET
Resistor
Q1
FQPF13N50C
Fairchild
R1
10k
1/4W
R2
300k
1/4W
Diode
R3
330k
1/2W
D1
1N4148
Fairchild
R4
100
1/4W
D2
BYV26C
600V, 1A
R5
20k
1/4W
D3
1N5819
Fairchild
R6
10
1/4W
D4
1N5819
Fairchild
R7
0.22
1/2W
ZD1
1N4746
18V
R8
10k
1/4W
R9
10k
1/4W
Bridge Diode
R10
2M
1/4W
BD
KBL406
600V/4A
R11
12.9k
1/4W
Line Filter
Capacitor
LF1
40mH
Wire 0.4mm
C1
150nF/275VAC
Box Capacitor
C2
330nF/275VAC
Box Capacitor
IC
C3
2.2nF/3kV
Ceramic Capacitor
IC1
FAN7528
Fairchild
C4
2.2nF/3kV Ceramic
Capacitor
C5
100nF/630V
Film Capacitor
TNR
C6
47uF/25V
Electrolytic Capacitor
V1
471
470V
C7
220nF/50V
Ceramic Capacitor
C8
1uF
MLCC
C9
100uF/450V
Electrolytic Capacitor
C10
12nF/100V
Film Capacitor
C11
56pF/50V
Ceramic Capacitor
18
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7. Layout
Figure 41. PCB Layout Considerations for FAN7528
8. Performance Data
90Vac
110Vac
220Vac
264Vac
100W
PF
0.999
0.998
0.992
0.986
THD
3.5%
3.9%
7.0%
7.4%
50W
PF
0.997
0.996
0.989
0.954
THD
5.8%
6.1%
11.9%
12.8%
Power Ground
Signal Ground
Separate the power ground
and the signal ground
Place the output voltage
sensing resistors close to IC
19
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Mechanical Dimensions
Package
Unit : mm
20
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FAN7528 Rev. 1.0.1
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Mechanical Dimensions
Package Unit : mm
21
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FAN7528 Rev. 1.0.1
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DISCLAIMER
FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY
PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. FAIRCHILD DOES NOT ASSUME ANY LIABILITY
ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER DOES IT
CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS.
TRADEMARKS
The following are registered and unregistered trademarks Fairchild Semiconductor owns or is authorized to use and is
not intended to be an exhaustive list of all such trademarks.
LIFE SUPPORT POLICY
FAIRCHILD'S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT
DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF FAIRCHILD SEMICONDUCTOR CORPORATION.
As used herein:
1. Life support devices or systems are devices or
systems which, (a) are intended for surgical implant into
the body, or (b) support or sustain life, or (c) whose
failure to perform when properly used in accordance
with instructions for use provided in the labeling, can be
reasonably expected to result in significant injury to the
user.
2. A critical component is any component of a life
support device or system whose failure to perform can
be reasonably expected to cause the failure of the life
support device or system, or to affect its safety or
effectiveness.
PRODUCT STATUS DEFINITIONS
Definition of Terms
Datasheet Identification
Product Status
Definition
Advance Information
Preliminary
No Identification Needed
Obsolete
This datasheet contains the design specifications for
product development. Specifications may change in
any manner without notice.
This datasheet contains preliminary data, and
supplementary data will be published at a later date.
Fairchild Semiconductor reserves the right to make
changes at any time without notice in order to improve
design.
This datasheet contains final specifications. Fairchild
Semiconductor reserves the right to make changes at
any time without notice in order to improve design.
This datasheet contains specifications on a product
that has been discontinued by Fairchild semiconductor.
The datasheet is printed for reference information only.
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In Design
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Full Production
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