Fairchild FAN7528MX Dual-output, critical conduction mode pfc controller Datasheet

FAN7528
Dual-Output, Critical Conduction Mode PFC Controller
Features
Description
„ Low Total Harmonic Distortion (THD)
The FAN7528 is an active power factor correction (PFC)
controller for boost PFC applications that operates in
critical conduction mode (CRM). It uses 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 sensing network
necessary for the current mode CRM PFC controller.
„ Dual Output Voltage Control
„ Precise Adjustable Output Over-Voltage Protection
„ Open-Feedback Protection and Disable Function
„ Zero Current Detector
„ 160µs Internal Start-up Timer
„ MOSFET Over-Current Protection
„ Under-Voltage Lockout with 3.5V Hysteresis
„ Low Start-up (40µA) 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
„ AN-6012: Design of Power Factor Correction Circuit
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 voltage.
It provides protection functions such as over-voltage protection, open-feedback protection, over-current protection, and under-voltage lockout protection. The FAN7528
can be disabled if the INV pin voltage is lower than 0.45V
and the operating current decreases to 65µA. Using a
new variable on-time control method, THD is lower than
the conventional CRM boost PFC ICs.
Using FAN7528
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
© 2005 Fairchild Semiconductor Corporation
FAN7528 Rev. 1.0.6
www.fairchildsemi.com
FAN7528 Dual-Output, Critical Conduction Mode PFC Controller
February 2007
FAN7528 Dual-Output, Critical Conduction Mode PFC Controller
Typical Application Diagrams
L
D
VO
AC IN
NAUX
VAUX
R2
RZCD
ZCD
CO
VCC
MOT
FAN7528
INV
CS
COMP
R1
GND
FAN7528 Rev. 1.01
Figure 1. Typical Boost PFC Application
Internal Block Diagram
2.5V
Ref
V CC 8
UVLO
8.5V
12V
V ref
Vcc
Internal
Bias
Drive
Output
Disable
160μs
Timer
ZCD 5
7 OUT
13V
S
6.7V
1.4V
Q
1.5V
R
Zero Current
Detector
CS 4
Disable
40k
8pF
0.8V
Ramp
Signal
MOT 3
OVP
OCP
Comparator
2.66V
2.55V
0.45V 0.35V
V CC =8.5V Reference Set
V CC =4.5V Reference Reset
Dual-Output Reference
Generator
1.5V/2.5V
1V Offset
Sawtooth
Generator
Error
Amplifier
Gm
1V ~ 5V
Range
6
2
GND
COMP
1 INV
FAN7528 Rev. 1.00
Figure 2. Functional Block Diagram of FAN7528
© 2005 Fairchild Semiconductor Corporation
FAN7528 Rev. 1.0.6
www.fairchildsemi.com
2
VCC
OUT
GND
ZCD
8
7
6
5
WWW
FAN7528
1
2
3
INV
COMP
MOT
4
CS
FAN7528 Rev. 1.00
Figure 3. Pin Configuration (Top View)
Pin Definitions
Pin #
Name
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 resistor 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, then 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 proper 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.
© 2005 Fairchild Semiconductor Corporation
FAN7528 Rev. 1.0.6
www.fairchildsemi.com
3
FAN7528 Dual-Output, Critical Conduction Mode PFC Controller
Pin Assignments
Stresses exceeding the absolute maximum ratings may damage the device. The device may not function or be operable above the recommended operating conditions and stressing the parts to these levels is not recommended. In addition, extended exposure to stresses above the recommended operating conditions may affect device reliability. The
absolute maximum ratings are stress ratings only. TA = 25°C unless otherwise specified.
Symbol
VCC
IOH, IOL
Iclamp
Parameter
Value
Unit
23
V
Peak Drive Output Current
±400
mA
Driver Output Clamping Diodes VO > VCC or VO < -0.3V
±10
mA
Supply Voltage
±10
mA
-0.3 to 6
V
150
°C
Operating Temperature Range
-40 to 125
°C
Storage Temperature Range
Idet
Detector Clamping Diodes
VIN
Error Amp, MOT, CS Input Voltages
TJ
Operating Junction Temperature
TA
TSTG
ESD
-65 to 150
°C
Human Body Model
2.0
kV
Machine Model
300
V
Value
Unit
8-DIP
110
°C/W
8-SOP
150
°C/W
Thermal Impedance
Symbol
θJA
Parameter
Thermal Resistance, Junction-to-Ambient
Note:
1. Regarding the test environment and PCB type, please refer to JESD51-2 and JESD51-10.
© 2005 Fairchild Semiconductor Corporation
FAN7528 Rev. 1.0.6
www.fairchildsemi.com
4
FAN7528 Dual-Output, Critical Conduction Mode PFC Controller
Absolute Maximum Ratings
VCC = 14V, TA = -40°C~125°C, unless otherwise specified.
Symbol
Parameter
Condition
Min.
Typ.
Max.
Unit
11
12
13
V
Under-Voltage Lockout Section
Start Threshold Voltage
VCC increasing
VTH(stop)
Stop Threshold Voltage
VCC decreasing
HY(uvlo)
UVLO Hysteresis
VTH(start)
8.0
8.5
9.0
V
3.0
3.5
4.0
V
VCC = VTH(start) – 0.2V
40
70
μA
Supply Current Section
IST
Start-up Supply Current
ICC
Operating Supply Current
Output no switching
1.5
3.0
mA
IDCC
Dynamic Operating Supply Current
50kHz, CL=1nF
2.5
4.0
mA
Operating Current at Disable
Vinv = 0V
40
65
90
μA
TA = 25°C
2.465
2.500
2.535
V
2.435
2.500
2.565
V
1.45
1.50
1.55
V
0.1
10.0
mV
ICC(dis)
Error Amplifier Section
Vref1
Voltage Feedback Input Threshold1
Vref2
Voltage Feedback Input Threshold2
ΔVref1
Line Regulation
VCC = 14V~23V
Vref1(1)
ΔVref3
Temperature Stability of
Ib(ea)
Input Bias Current
Vinv = 1V~4V
Isource
Output Source Current
Vinv = 2.4V
-12
μA
Output Sink Current
Vinv = 2.6V
12
μA
Isink
20
-0.5
mV
0.5
μA
Veao(H)
Output Upper Clamp Voltage
4.5
5.5
6.5
V
Veao(Z)
Zero Duty Cycle Output Voltage
0.7
1.0
1.3
V
Transconductance(1)
90
115
140
μmho
1.24
1.30
1.36
V
3.0
4.5
6.0
V
gm
VTH(in)
VTH(reset)
Output Voltage Selection Threshold
Output Voltage Reset
TA = 25°C
Threshold(1)
Maximum On-Time Section
Vmot
tON-max
Maximum On-time Voltage
Rmot = 13.7k
0.95
1.00
1.05
V
Maximum On-time Programming
Rmot = 13.7k, TA = 25°C
18.0
22.5
27.0
μs
0.7
0.8
0.9
V
-1.0
-0.1
1.0
μA
350
500
ns
Current Sense Section
VCS(limit)
Ib(cs)
td(cs)
Current Sense Input Threshold
Voltage Limit
Input Bias Current
VCS = 0V~1V
(1)
Current Sense Delay to Output
© 2005 Fairchild Semiconductor Corporation
FAN7528 Rev. 1.0.6
www.fairchildsemi.com
5
FAN7528 Dual-Output, Critical Conduction Mode PFC Controller
Electrical Characteristics
VCC = 14V, TA = -40°C~125°C, unless otherwise specified.
Symbol
Parameter
Condition
Min.
Typ.
Max.
Unit
1.35
1.50
1.65
V
Zero Current Detection Section
VTH(ZCD)
Input Voltage Threshold(1)
(1)
HY(ZCD)
Detect Hysteresis
0.05
0.10
0.15
V
Vclamp(h)
Input High Clamp Voltage
Idet = 3mA
6.0
6.7
7.4
V
Vclamp(l)
Input Low Clamp Voltage
Idet = -3mA
0
0.6
1.0
V
-1.0
-0.1
1.0
μA
Ib(ZCD)
Input Bias Current
VZCD = 1V~5V
(1)
Isource(zcd)
Source Current Capability
-10
mA
Isink(zcd)
Sink Current Capability(1)
10
mA
200
ns
11.0
12.8
V
tdead
Maximum Delay from ZCD to Output
Turn-on(1)
100
Output Section
VOH
Output Voltage High
IO = -100mA
VOL
Output Voltage Low
IO = 100mA
1.0
2.5
V
tr
Rising
Time(1)
CL = 1nF
50
100
ns
Falling
Time(1)
50
100
ns
13.0
14.5
V
1
V
tf
9.2
CL = 1nF
VO(max)
Maximum Output Voltage
VCC = 20V, IO = 100μA
VO(uvlo)
Output Voltage with UVLO Activated
VCC = 5V, IO = 100μA
11.5
Restart Timer Section
td(rst)
Restart Timer Delay
40
160
360
μs
2.60
2.66
2.72
V
0.06
0.11
0.16
V
Over-Voltage Protection Section
VOVP
HY(ovp)
OVP Threshold Voltage
TA = 25°C
OVP Hysteresis
Enable Section
VTH(en)
Enable Threshold Voltage
0.40
0.45
0.50
V
HY(en)
Enable Hysteresis
0.05
0.10
0.15
V
Note:
1. These parameters, although guaranteed by design, are not tested in production.
© 2005 Fairchild Semiconductor Corporation
FAN7528 Rev. 1.0.6
www.fairchildsemi.com
6
FAN7528 Dual-Output, Critical Conduction Mode PFC Controller
Electrical Characteristics (Continued)
12.8
9.2
VTH(stop) [V]
VTH(start) [V]
12.4
12.0
11.6
11.2
8.8
8.4
8.0
7.6
-60 -40 -20
0
20 40 60 80 100 120 140
-60 -40 -20
0
Temperature [°C]
Temperature [°C]
Figure 4. Start Threshold Voltage vs. Temp.
Figure 5. Stop Threshold Voltage vs. Temp.
70
4.0
60
3.8
50
3.6
IST [μA]
HY(uvlo) [V]
20 40 60 80 100 120 140
3.4
3.2
40
30
20
10
0
3.0
-60 -40 -20
0
-60 -40 -20
20 40 60 80 100 120 140
0
20 40 60 80 100 120 140
Temperature [°C]
Temperature [°C]
Figure 6. UVLO Hysteresis vs. Temp.
Figure 7. Start-up Supply Current vs. Temp.
3.0
4.0
3.5
2.5
3.0
IDCC [mA]
ICC [mA]
2.0
1.5
1.0
0.5
2.5
2.0
1.5
1.0
0.5
0.0
0.0
-60 -40 -20
0
-60 -40 -20
20 40 60 80 100 120 140
Temperature [°C]
20 40 60 80 100 120 140
Temperature [°C]
Figure 8. Operating Supply Current vs. Temp.
Figure 9. Dynamic Operating Current vs. Temp.
© 2005 Fairchild Semiconductor Corporation
FAN7528 Rev. 1.0.6
0
www.fairchildsemi.com
7
FAN7528 Dual-Output, Critical Conduction Mode PFC Controller
Typical Performance Characteristics
2.56
80
2.54
2.52
70
Vref1 [V]
ICC(dis) [μA]
90
2.50
60
2.48
50
2.46
2.44
40
-60 -40 -20
0
-60 -40 -20
20 40 60 80 100 120 140
0
Figure 11. Vref1 vs. Temp.
1.54
0.4
1.52
0.2
Ib(ea) [μA]
Vref2 [V]
Figure 10. ICC at Disable vs. Temp.
1.50
1.48
0.0
-0.2
-0.4
1.46
-60 -40 -20
0
-60 -40 -20
20 40 60 80 100 120 140
0
20 40 60 80 100 120 140
Temperature [°C]
Temperature [°C]
Figure 12. Vref2 vs. Temp.
Figure 13. Input Bias Current vs. Temp.
-6
18
-9
15
-12
Isink [μA]
Isource [μA]
20 40 60 80 100 120 140
Temperature [°C]
Temperature [°C]
-15
-18
12
9
6
-60 -40 -20
0
-60 -40 -20
20 40 60 80 100 120 140
Temperature [°C]
20 40 60 80 100 120 140
Temperature [°C]
Figure 14. Error Amp. Source Current vs. Temp.
Figure 15. Error Amp. Sink Current vs. Temp.
© 2005 Fairchild Semiconductor Corporation
FAN7528 Rev. 1.0.6
0
www.fairchildsemi.com
8
FAN7528 Dual-Output, Critical Conduction Mode PFC Controller
Typical Performance Characteristics (Continued)
6.5
1.3
1.2
6.0
Veao(Z) [V]
Veao(H) [V]
1.1
5.5
5.0
1.0
0.9
0.8
4.5
0.7
-60 -40 -20
0
20 40 60 80 100 120 140
-60 -40 -20
Temperature [°C]
0
20 40 60 80 100 120 140
Temperature [°C]
Figure 16. Error Amp. Clamp Voltage vs. Temp.
Figure 17. Zero Duty Output Voltage vs. Temp.
1.36
1.04
1.34
1.02
Vmot [V]
VTH(IN) [V]
1.32
1.30
1.28
1.26
1.00
0.98
0.96
1.24
-60 -40 -20
0
20 40 60 80 100 120 140
-60 -40 -20
0
Temperature [°C]
Figure 18. Output Select Threshold vs. Temp.
Figure 19. MOT Pin Voltage vs. Temp.
26
0.88
24
0.84
VCS(limit) [V]
tON(max) [μs]
20 40 60 80 100 120 140
Temperature [°C]
22
20
0.80
0.76
0.72
18
-60 -40 -20
0
20 40 60 80 100 120 140
-60 -40 -20
Temperature [°C]
20 40 60 80 100 120 140
Temperature [°C]
Figure 20. Maximum On-Time vs. Temp.
Figure 21. Current Limit vs. Temp.
© 2005 Fairchild Semiconductor Corporation
FAN7528 Rev. 1.0.6
0
www.fairchildsemi.com
9
FAN7528 Dual-Output, Critical Conduction Mode PFC Controller
Typical Performance Characteristics (Continued)
7.4
0.9
7.2
0.6
7.0
Vclamp(H) [V]
Ib(CS) [μA]
0.3
0.0
-0.3
-0.6
6.8
6.6
6.4
6.2
-0.9
6.0
-60 -40 -20
0
20 40 60 80 100 120 140
-60 -40 -20
Temperature [°C]
0
20 40 60 80 100 120 140
Temperature [°C]
Figure 22. CS Input Bias Current vs. Temp.
Figure 23. ZCD Input High Clamp vs. Temp.
1.0
0.8
0.8
Ib(ZCD) [μA]
Vclamp(L) [V]
0.4
0.6
0.4
0.0
-0.4
0.2
-0.8
0.0
-60 -40 -20
0
20 40 60 80 100 120 140
-60 -40 -20
0
Temperature [°C]
Figure 24. ZCD Input Low Clamp vs. Temp.
Figure 25. ZCD Input Bias Current vs. Temp.
2.5
12.5
2.0
12.0
11.5
1.5
VOL [V]
VOH [V]
20 40 60 80 100 120 140
Temperature [°C]
11.0
10.5
10.0
1.0
0.5
9.5
0.0
-60 -40 -20
0
20 40 60 80 100 120 140
-60 -40 -20
Temperature [°C]
20 40 60 80 100 120 140
Temperature [°C]
Figure 26. Output Voltage High vs. Temp.
Figure 27. Output Voltage Low vs. Temp.
© 2005 Fairchild Semiconductor Corporation
FAN7528 Rev. 1.0.6
0
www.fairchildsemi.com
10
FAN7528 Dual-Output, Critical Conduction Mode PFC Controller
Typical Performance Characteristics (Continued)
14.5
1.0
14.0
0.8
VO(uvlo) [V]
VO(max) [V]
13.5
13.0
12.5
0.6
0.4
0.2
12.0
11.5
0.0
-60 -40 -20
0
20 40 60 80 100 120 140
-60 -40 -20
0
Temperature [°C]
Figure 28. Maximum Output Voltage vs. Temp.
Figure 29. Output Voltage when UVLO vs. Temp.
400
2.74
350
2.72
2.70
250
VOVP [V]
td(rst) [μs]
300
200
150
100
2.68
2.66
2.64
2.62
50
2.60
-60 -40 -20
0
20 40 60 80 100 120 140
-60 -40 -20
0
Temperature [°C]
20 40 60 80 100 120 140
Temperature [°C]
Figure 30. Restart Timer Delay vs. Temp.
Figure 31. Over-Voltage Protection vs. Temp.
0.14
0.50
0.48
VTH(en) [V]
0.12
HY(OVP) [V]
20 40 60 80 100 120 140
Temperature [°C]
0.10
0.08
0.46
0.44
0.42
0.06
0.40
-60 -40 -20
0
20 40 60 80 100 120 140
-60 -40 -20
Temperature [°C]
20 40 60 80 100 120 140
Temperature [°C]
Figure 32. OVP Hysteresis vs. Temp.
Figure 33. Enable Threshold Voltage vs. Temp.
© 2005 Fairchild Semiconductor Corporation
FAN7528 Rev. 1.0.6
0
www.fairchildsemi.com
11
FAN7528 Dual-Output, Critical Conduction Mode PFC Controller
Typical Performance Characteristics (Continued)
FAN7528 Dual-Output, Critical Conduction Mode PFC Controller
Typical Performance Characteristics (Continued)
0.14
HY(en) [V]
0.12
0.10
0.08
0.06
-60 -40 -20
0
20 40 60 80 100 120 140
Temperature [°C]
Figure 34. Enable Hysteresis vs. Temp.
© 2005 Fairchild Semiconductor Corporation
FAN7528 Rev. 1.0.6
www.fairchildsemi.com
12
1. Error Amplifier Block
1.2 Over-Voltage Protection Function
The error amplifier block has several functions, such as
dual output function, over-voltage protection function,
and disable function.
The control speed of the PFC converter is very slow;
therefore, the over-voltage protection (OVP) of the output voltage is very important. 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.
1.1 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 output 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 voltage
reaches 8.5V, the dual-output reference generator compares 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 1.5V. If the INV pin voltage is higher than
1.3V, the reference voltage is set to 2.5V. That means if
the output voltage of the boost converter is set to 400V at
high line, the output voltage is 240V (400V*1.5/2.5) at
low line. If the output voltage is set to 390V at high line,
the output voltage is 234V at low line. Because this block
does not need the input voltage sensing network, the
power loss and cost related with the sensing network
can be saved. The reference voltage of the error amplifier is not reset until VCC goes below 4.5V.
2.66V
1.3 Disable Function
If the INV pin voltage is lower than 0.45V, most of the
internal block is disabled, the operating current is
reduced to be 65µA, 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 difference between the inverting input and the
non-inverting input of the amplifier. Some resistors and
capacitors should be connected 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 voltage of the ZCD pin goes higher than
1.5V, the ZCD comparator waits until the voltage goes
below 1.4V. If the voltage goes below 1.4V, the zero current detector turns on the MOSFET. The ZCD pin is protected internally by two clamps, 6.7V high clamp and
0.6V low clamp. The 160µs timer generates a MOSFET
turn-on signal if the drive output has been low for more
than 160µs from the falling edge of the drive output.
2.55V
OVP
Disable
0.45V
0.35V
Dual-Output
Reference
Generator
Error Amp
VOUT
1.5V/2.5V
Gm
160μs
Timer
VIN
INV
ZCD
1
RZCD
2
Turn-on
Signal
COMP
5
S
6.7V
Q
1.4V
1.5V
Zero Current
Detector
R
FAN7528 Rev. 1.00
Figure 36. Zero Current Detector Block
FAN7528 Rev. 1.00
Figure 35. Error Amplifier Block
© 2005 Fairchild Semiconductor Corporation
FAN7528 Rev. 1.0.6
www.fairchildsemi.com
13
FAN7528 Dual-Output, Critical Conduction Mode PFC Controller
Applications Information
4. Over-Current Protection Block
The output of the error amplifier and the output of the
sawtooth generator are compared to determine the
MOSFET turn-off instance. The slope of the sawtooth is
determined by an external 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; therefore, 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 necessary maximum on-time depends on
the boost inductor, lowest AC line voltage, and maximum
output power. The resistor value should be designed
properly.
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 generates a protection signal. An internal RC
filter is included to filter switching noise.
0.8V
Over-Current
Protection
Comparator
FAN7528 Rev. 1.00
Figure 38. Over-Current Protection Block
Off Signal
3
4
8pF
5. Switch Drive Block
1V
MOT
OCP
Signal
40k
CS
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 13V.
Sawtooth
Generator
1V
Error Amp
Output
FAN7528 Rev. 1.00
6. Under-Voltage Lockout Block
Figure 37. Sawtooth Generator 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.
© 2005 Fairchild Semiconductor Corporation
FAN7528 Rev. 1.0.6
www.fairchildsemi.com
14
FAN7528 Dual-Output, Critical Conduction Mode PFC Controller
3. Sawtooth Generator Block
Application
Output power
Input voltage
Output voltage
Adapter
100W
Universal input
(90~264 Vac)
389V/232V
Features
„ High efficiency (>90% at 90 Vac input)
„ Low THD (total harmonic distortion) (<10% at 264 Vac 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 components for low THD are R2, R5, and C11.
1. Schematic
T1
PFC OUTPUT
VAUX
BD
D2
C5
R4
R3
R5
NTC
Q1
R6
ZD1
7
C2
R9
1
2
3
C7
R1
CS
C1
MOT
INV
R2
V1
C9
5
FAN7528
COMP
LF1
6
GND
VCC
8
C11
OUT
C4
ZCD
D1
C3
R11
4
R8
F1
C6
R10
D3
C10
C8
R7
D4
FAN7528 Rev. 1.00
AC INPUT
Figure 39. Schematic
© 2005 Fairchild Semiconductor Corporation
FAN7528 Rev. 1.0.6
www.fairchildsemi.com
15
FAN7528 Dual-Output, Critical Conduction Mode PFC Controller
Typical Application Circuit
1
NVcc
2
3
Np
5
FAN7528 Rev. 1.00
Figure 40. Inductor Schematic Diagram
3. Winding Specification
No
Pin (s→f)
5→3
Np
Wire
0.2φ
× 10
Turns
Winding Method
44
Solenoid Winding
6
Solenoid Winding
Insulation: Polyester Tape t = 0.050mm, 4 Layers
2→1
NVcc
0.2φ × 1
Outer Insulation: Polyester Tape t = 0.050mm, 4 Layers
Air Gap: 0.6mm for each leg
4. Electrical Characteristics
Inductance
Pin
Specification
Remarks
3–5
400µH ± 10%
100kHz, 1V
5. Core & Bobbin
„ Core: EI 3026
„ Bobbin: EI3026
„ Ae(mm2): 111
© 2005 Fairchild Semiconductor Corporation
FAN7528 Rev. 1.0.6
www.fairchildsemi.com
16
FAN7528 Dual-Output, Critical Conduction Mode PFC Controller
2. Inductor Schematic Diagram
Part
Value
Note
Part
Value
Fuse
F1
Note
Inductor
3A/250V
T1
400µH
EI3026
NTC
NTC
10D-9
MOSFET
Resistor
Q1
FQPF13N50C
Fairchild
R1
10kΩ
1/4W
R2
370kΩ
1/4W
R3
330kΩ
1/2W
D1
1N4148
Fairchild
R4
150Ω
1/2W
D2
BYV26C
600V, 1A
R5
20kΩ
1/4W
D3
1N5819
Fairchild
R6
10Ω
1/4W
D4
1N5819
Fairchild
R7
0.22Ω
1/2W
ZD1
1N4746
18V
R8
10kΩ
1/4W
BD
KBL06
R9
10kΩ
1/4W
R10
2MΩ
1/4W
R11
12.9kΩ
1/4W
Diode
Bridge Diode
Capacitor
Line Filter
C1
150nF/275VAC
Box Capacitor
C2
330nF/275VAC
Box Capacitor
C3
2.2nF/3kV
Ceramic Capacitor
C4
2.2nF/3kV
Ceramic Capacitor
C5
150nF/630V
Film Capacitor
C6
47uF/25V
Electrolytic Capacitor
C7
47nF/50V
Ceramic Capacitor
C8
220nF
MLCC
C9
100µF/450V
Electrolytic Capacitor
C10
12nF/100V
Film Capacitor
C11
47pF/50V
Ceramic Capacitor
LF1
40mH
Wire 0.4mm
IC
IC1
FAN7528
Fairchild
TNR
V1
© 2005 Fairchild Semiconductor Corporation
FAN7528 Rev. 1.0.6
600V/4A
471
470V
www.fairchildsemi.com
17
FAN7528 Dual-Output, Critical Conduction Mode PFC Controller
6. Demo Circuit Part List
FAN7528 Dual-Output, Critical Conduction Mode PFC Controller
7. Layout
Power Ground
Signal Ground
Separate the power ground and the
signal ground
Place the output voltage sensing resistors
close to IC
Figure 41. PCB Layout Considerations for FAN7528
8. Performance Data
100W
50W
90 Vac
110 Vac
220 Vac
264 Vac
PF
0.999
0.998
0.991
0.983
THD
3.5%
3.6%
6.1%
7.3%
PF
0.997
0.996
0.971
0.947
THD
5.1%
5.5%
11.1%
13.0%
© 2005 Fairchild Semiconductor Corporation
FAN7528 Rev. 1.0.6
www.fairchildsemi.com
18
FAN7528 Dual-Output, Critical Conduction Mode PFC Controller
Mechanical Dimensions
8-DIP
Dimensions are in millimeters unless otherwise noted.
Figure 42. 8-Lead Dual In-Line Package (DIP)
© 2005 Fairchild Semiconductor Corporation
FAN7528 Rev. 1.0.6
www.fairchildsemi.com
19
FAN7528 Dual-Output, Critical Conduction Mode PFC Controller
Mechanical Dimensions
8-SOP
Dimensions are in millimeters unless otherwise noted.
Figure 43. 8-Lead Small Outline Package (SOP)
© 2005 Fairchild Semiconductor Corporation
FAN7528 Rev. 1.0.6
www.fairchildsemi.com
20
FAN7528 Dual-Output, Critical Conduction Mode PFC Controller
© 2005 Fairchild Semiconductor Corporation
FAN7528 Rev. 1.0.6
www.fairchildsemi.com
21
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