FAIRCHILD FSDM0565RB

FSQ0565R, FSQ0765R
Green-Mode Fairchild Power Switch (FPS™) for
Quasi-Resonant Operation - Low EMI and High Efficiency
Features
Description
„ Optimized for Quasi-Resonant Converter (QRC)
A Quasi-Resonant Converter (QRC) generally shows
lower EMI and higher power conversion efficiency than a
conventional hard-switched converter with a fixed
switching frequency. The FSQ-series is an integrated
Pulse-Width Modulation (PWM) controller and
SenseFET specifically designed for quasi-resonant
operation and Alternating Valley Switching (AVS). The
PWM controller includes an integrated fixed-frequency
oscillator, Under-Voltage Lockout (UVLO), LeadingEdge Blanking (LEB), optimized gate driver, internal softstart, temperature-compensated precise current sources
for a loop compensation, and self-protection circuitry.
Compared with a discrete MOSFET and PWM controller
solution, the FSQ-series can reduce total cost,
component count, size, and weight; while simultaneously
increasing efficiency, productivity, and system reliability.
This device provides a basic platform that is well suited
for cost-effective designs of quasi-resonant switching
flyback converters.
„ Low EMI through Variable Frequency Control and AVS
(Alternating Valley Switching)
„ High-Efficiency through Minimum Voltage Switching
„ Narrow Frequency Variation Range over Wide Load
and Input Voltage Variation
„ Advanced Burst-Mode Operation for Low Standby
Power Consumption
„ Simple Scheme for Sync Voltage Detection
„ Pulse-by-Pulse Current Limit
„ Various Protection functions: Overload Protection
„
„
„
„
(OLP), Over-Voltage Protection (OVP), Abnormal
Over-Current Protection (AOCP), Internal Thermal
Shutdown (TSD) with Hysteresis, Output Short
Protection (OSP)
Under-Voltage Lockout (UVLO) with Hysteresis
Internal Start-up Circuit
Internal High-Voltage Sense FET (650V)
Built-in Soft-Start (15ms)
Applications
„ Power Supply for LCD TV and Monitor, VCR, SVR,
STB, and DVD & DVD Recorder
„ Adapter
Related Resourses
Visit: http://www.fairchildsemi.com/apnotes/ for:
„ AN-4134: Design Guidelines for Offline Forward
„
„
„
„
„
„
„
Converters Using Fairchild Power Switch (FPS™)
AN-4137: Design Guidelines for Offline Flyback
Converters Using Fairchild Power Switch (FPS™)
AN-4140: Transformer Design Consideration for
Offline Flyback Converters Using Fairchild Power
Switch (FPS™)
AN-4141: Troubleshooting and Design Tips for
Fairchild Power Switch (FPS™) Flyback Applications
AN-4145: Electromagnetic Compatibility for Power
Converters
AN-4147: Design Guidelines for RCD Snubber of
Flyback
AN-4148: Audible Noise Reduction Techniques for
Fairchild Power Switch Fairchild Power Switch(FPS™)
Applications
AN-4150: Design Guidelines for Flyback Converters
Using FSQ-Series Fairchild Power Switch (FPS™)
© 2007 Fairchild Semiconductor Corporation
FSQ0565R, FSQ0765R Rev. 1.0.0
www.fairchildsemi.com
FSQ0565R, FSQ0765R — Green-Mode Farichild Power Switch (FPS™) for Quasi-Resonant Operation
October 2007
Maximum Output Power(1)
Product
Number
PKG.(5)
Operating Current RDS(ON)
Temp.
Limit
Max.
230VAC±15%(2)
85-265VAC
Adapter(3)
Open
Frame(4)
Adapter(3)
Open
Frame(4)
Replaces
Devices
FSQ0565R TO-220F-6L -25 to +85°C
3.0A
2.2Ω
70W
80W
41W
60W
FSCM0565R
FSDM0565RB
FSQ0765R TO-220F-6L -25 to +85°C
3.5A
1.6Ω
80W
90W
48W
70W
FSCM0765R
FSDM0765RB
Notes:
1. The junction temperature can limit the maximum output power.
2. 230VAC or 100/115VAC with doubler.
3. Typical continuous power in a non-ventilated enclosed adapter measured at 50°C ambient temperature.
4. Maximum practical continuous power in an open-frame design at 50°C ambient.
5. Pb-free package per JEDEC J-STD-020B.
© 2007 Fairchild Semiconductor Corporation
FSQ0565R, FSQ0765R Rev. 1.0.0
www.fairchildsemi.com
2
FSQ0565R, FSQ0765R — Green-Mode Farichild Power Switch (FPS™) for Quasi-Resonant Operation
Ordering Information
VO
AC
IN
Vstr
PWM
Sync
Drain
GND
VCC
FB
FSQ0765R Rev.00
Figure 1. Typical Flyback Application
Internal Block Diagram
Sync
5
AVS
VCC
Idelay
FB
4
VCC
Drain
6
3
1
OSC
Vref
0.35/0.55
VBurst
Vref
Vstr
VCC good
8V/12V
IFB
PWM
3R
R
SoftStart
S Q
LEB
250ns
Gate
driver
R Q
tON < tOSP
after SS
VOSP
LPF
AOCP
VSD
S
TSD
Q
2
VOCP
(1.1V)
GND
R Q
LPF
VOVP
VCC good
FSQ0765R Rev.00
Figure 2. Internal Block Diagram
© 2007 Fairchild Semiconductor Corporation
FSQ0565R, FSQ0765R Rev. 1.0.0
www.fairchildsemi.com
3
FSQ0565R, FSQ0765R — Green-Mode Farichild Power Switch (FPS™) for Quasi-Resonant Operation
Application Diagram
6. Vstr
5. Sync
4. FB
3. VCC
2. GND
1. Drain
FSQ0765R Rev.00
Figure 3. Pin Configuration (Top View)
Pin Definitions
Pin #
Name
1
Drain
SenseFET drain. High-voltage power SenseFET drain connection.
2
GND
Ground. This pin is the control ground and the SenseFET source.
3
VCC
Power Supply. This pin is the positive supply input. This pin provides internal operating current for both start-up and steady-state operation.
4
FB
Feedback. This pin is internally connected to the inverting input of the PWM comparator. The
collector of an opto-coupler is typically tied to this pin. For stable operation, a capacitor should
be placed between this pin and GND. If the voltage of this pin reaches 6V, the overload protection triggers, which shuts down the FPS.
5
Sync
Sync. This pin is internally connected to the sync-detect comparator for quasi-resonant switching. In normal quasi-resonant operation, the threshold of the sync comparator is 1.2V/1.0V.
Vstr
Start-up. This pin is connected directly, or through a resistor, to the high-voltage DC link. At
start-up, the internal high-voltage current source supplies internal bias and charges the external capacitor connected to the VCC pin. Once VCC reaches 12V, the internal current source is
disabled. It is not recommended to connect Vstr and Drain together.
6
Description
© 2007 Fairchild Semiconductor Corporation
FSQ0565R, FSQ0765R Rev. 1.0.0
www.fairchildsemi.com
4
FSQ0565R, FSQ0765R — Green-Mode Farichild Power Switch (FPS™) for Quasi-Resonant Operation
Pin Configuration
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
Parameter
Min.
Max.
Unit
Vstr
Vstr Pin Voltage
500
V
VDS
Drain Pin Voltage
650
V
VCC
Supply Voltage
VFB
Feedback Voltage Range
VSync
IDM
-0.3
Sync Pin Voltage
-0.3
Drain Current Pulsed
Continuous Drain
V
11
V
A
FSQ0765R
15
A
Current(6)
TC = 25°C
2.8
TC = 100°C
1.7
TC = 25°C
3.8
TC = 100°C
2.4
A
A
FSQ0565R
190
mJ
FSQ0765R
370
mJ
45
W
Operating Junction Temperature
Internally limited
°C
Operating Ambient Temperature
-25
°C
Storage Temperature
-55
EAS
Single Pulsed Avalanche
Energy(7)
PD
Total Power Dissipation(Tc=25oC)
TJ
TA
ESD
13
11
FSQ0765R
TSTG
V
FSQ0565R
FSQ0565R
ID
20
+85
+150
°C
Electrostatic Discharge Capability, Human Body Model
2.0
kV
Electrostatic Discharge Capability, Charged Device Model
2.0
kV
Notes:
6. Repetitive rating: Pulse width limited by maximum junction temperature.
7. L=14mH, starting TJ=25°C.
Thermal Impedance
TA = 25°C unless otherwise specified.
Symbol
θJA
θJC
Parameter
Junction-to-Ambient Thermal
Junction-to-Case Thermal
Package
Resistance(8)
Resistance(9)
TO-220F-6L
Value
Unit
50
°C/W
2.8
°C/W
Notes:
8. Free standing with no heat-sink under natural convection.
9. Infinite cooling condition - refer to the SEMI G30-88.
© 2007 Fairchild Semiconductor Corporation
FSQ0565R, FSQ0765R Rev. 1.0.0
www.fairchildsemi.com
5
FSQ0565R, FSQ0765R — Green-Mode Farichild Power Switch (FPS™) for Quasi-Resonant Operation
Absolute Maximum Ratings
TA = 25°C unless otherwise specified.
Symbol
Parameter
Condition
Min. Typ. Max. Unit
SENSEFET SECTION
BVDSS
Drain Source Breakdown Voltage
VCC = 0V, ID = 100µA
IDSS
Zero-Gate-Voltage Drain Current
VDS = 560V
RDS(ON)
Drain-Source On-State
Resistance
COSS
Output Capacitance
td(on)
Turn-On Delay Time
tr
td(off)
tf
TJ = 25°C, ID = 0.5A
1.76
2.20
FSQ0765R
TJ = 25°C, ID = 0.5A
1.4
1.6
FSQ0565R
FSQ0565R
FSQ0765R
FSQ0565R
FSQ0765R
FSQ0565R
Turn-Off Delay Time
FSQ0765R
FSQ0565R
Fall Time
V
250
FSQ0565R
FSQ0765R
Rise Time
650
FSQ0765R
78
VGS = 0V, VDS = 25V, f = 1MHz
22
ns
25
52
VDD = 350V, ID = 25mA
ns
60
95
VDD = 350V, ID = 25mA
ns
115
50
VDD = 350V, ID = 25mA
Ω
pF
100
VDD = 350V, ID = 25mA
µA
ns
65
CONTROL SECTION
tON.MAX
Maximum On Time
TJ = 25°C
8.8
10.0
11.2
µs
13.2
15.0
16.8
µs
tB
Blanking Time
TJ = 25°C, Vsync = 5V
tW
Detection Time Window
TJ = 25°C, Vsync = 0V
fS
Initial Switching Frequency
ΔfS
tAVS
Switching Frequency
Variation(9)
On Time
6.0
59.6
66.7
75.8
kHz
-25°C < TJ < 85°C
±5
±10
%
at VIN = 240VDC, Lm = 360μH
(AVS triggered when VAVS>spec
& tAVS<spec.)
4.0
µs
1.2
V
VAVS
AVS Triggering
Threshold(9)
tSW
Switching Time Variance by AVS(9)
Sync = 500kHz sine input
VFB = 1.2V, tON = 4.0µs
13.5
IFB
Feedback Source Current
VFB = 0V
700
Minimum Duty Cycle
VFB = 0V
DMIN
VSTART
VSTOP
tS/S
UVLO Threshold Voltage
Internal Soft-Start Time
Feedback
Voltage
µs
11
After turn-on
7
With free-running frequency
20.5
µs
1100
µA
0
%
12
13
V
8
9
900
17.5
V
ms
BURST-MODE SECTION
TJ = 25°C, tPD = 200ns(8)
VBURH
VBURL
Burst-Mode Voltages
Hysteresis
0.45
0.55
0.65
0.25
0.35
0.45
200
V
V
mV
Continued on the following page...
© 2007 Fairchild Semiconductor Corporation
FSQ0565R, FSQ0765R Rev. 1.0.0
www.fairchildsemi.com
6
FSQ0565R, FSQ0765R — Green-Mode Farichild Power Switch (FPS™) for Quasi-Resonant Operation
Electrical Characteristics
TA = 25°C unless otherwise specified.
Symbol
Parameter
Condition
Min. Typ. Max. Unit
PROTECTION SECTION
FSQ0565R
TJ = 25°C, di/dt = 370mA/µs
2.64
3.00
3.36
FSQ0765R
TJ = 25°C, di/dt = 460mA/µs
3.08
3.50
3.92
Shutdown Feedback Voltage
VCC = 15V
5.5
6.0
6.5
V
Shutdown Delay Current
VFB = 5V
4
5
6
µA
1.4
µs
ILIMIT
Peak Current
Limit
VSD
IDELAY
tLEB
Hys
1.2
ns
Output Short
Protection(9)
Threshold Feedback
Voltage
TJ = 25°C
OSP triggered when tON<tOSP ,
VFB>VOSP & lasts longer than
t
Feedback Blanking Time OSP_FB
1.8
2
2.5
3.0
Thermal
Shutdown(9)
Shutdown Temperature
125
140
155
tOSP_FB
TSD
250
Threshold Time
Leading-Edge Blanking
tOSP
VOSP
Time(9)
Hysteresis
A
2.0
V
60
µs
°C
SYNC SECTION
VSH1
VSL1
tsync
VSH2
VSL2
VCLAMP
VOVP
tOVP
Sync Threshold Voltage 1
VCC = 15V, VFB = 2V
1.0
1.2
1.4
0.8
1.0
1.2
Sync Delay Time(9)(10)
230
Sync Threshold Voltage 2
VCC = 15V, VFB = 2V
Low Clamp Voltage
ISYNC_MAX = 800µA
ISYNC_MIN = 50µA
Over-Voltage Threshold Voltage
Protection
Blanking Time(9)
VCC = 15V, VFB = 2V
V
ns
4.3
4.7
5.1
4.0
4.4
4.8
0.0
0.4
0.8
V
7
8
9
V
1.0
1.7
2.4
µs
1
3
5
mA
V
TOTAL DEVICE SECTION
IOP
ISTART
ICH
VSTR
Operating Supply Current
(Control Part Only)
VCC = 13V
Start Current
VCC = 10V
(before VCC reaches VSTART)
350
450
550
µA
Start-up Charging Current
VCC = 0V, VSTR = mininmum
50V
0.65
0.85
1.00
mA
Minimum VSTR Supply Voltage
26
V
Notes:
8. Propagation delay in the control IC.
9. Guaranteed by design; not tested in production.
10. Includes gate turn-on time.
© 2007 Fairchild Semiconductor Corporation
FSQ0565R, FSQ0765R Rev. 1.0.0
www.fairchildsemi.com
7
FSQ0565R, FSQ0765R — Green-Mode Farichild Power Switch (FPS™) for Quasi-Resonant Operation
Electrical Characteristics (Continued)
Function
Operation Method
EMI Reduction
FSDM0x65RE
Constant
Frequency PWM
Frequency
Modulation
FSQ-Series
Quasi-Resonant
Operation
„ Reduced EMI noise
„ Reduced components to detect valley point
„ Valley Switching
Reduce EMI Noise „ Inherent Frequency Modulation
„ Alternate Valley Switching
CCM or AVS
Based on Load „ Improves efficiency by introducing hybrid control
and Input Condition
Hybrid Control
Burst-Mode
Operation
Burst-Mode
Operation
Advanced
Burst-Mode
Operation
Strong Protections
OLP, OVP
OLP, OVP,
AOCP, OSP
TSD
145°C without
Hysteresis
140°C with 60°C
Hysteresis
© 2007 Fairchild Semiconductor Corporation
FSQ0565R, FSQ0765R Rev. 1.0.0
FSQ-Series Advantages
„ Improved efficiency by valley switching
„ Improved standby power by AVS in burst-mode
„ Improved reliability through precise AOCP
„ Improved reliability through precise OSP
„ Stable and reliable TSD operation
„ Converter temperature range
www.fairchildsemi.com
8
FSQ0565R, FSQ0765R — Green-Mode Farichild Power Switch (FPS™) for Quasi-Resonant Operation
Comparison Between FSDM0x65RNB and FSQ-Series
1.2
Normalized
Normalized
These characteristic graphs are normalized at TA= 25°C.
1.0
0.8
1.2
1.0
0.8
0.6
0.6
0.4
0.4
0.2
0.2
0.0
-25
0
25
50
75
100
0.0
-25
125
0
Temperature [°C]
1.2
1.0
0.8
0.4
0.2
0.2
75
100
0.0
-25
125
0
1.2
1.0
0.8
125
0.8
0.4
0.4
0.2
0.2
75
100
0.0
-25
125
0
25
50
75
100
125
Temperature [°C]
Temperature [°C]
Figure 8. Initial Switching Frequency (fS) vs. TA
Figure 9. Maximum On Time (tON.MAX) vs. TA
© 2007 Fairchild Semiconductor Corporation
FSQ0565R, FSQ0765R Rev. 1.0.0
100
1.0
0.6
50
75
1.2
0.6
25
50
Figure 7. Start-up Charging Current (ICH) vs. TA
Normalized
Normalized
Figure 6. UVLO Stop Threshold Voltage
(VSTOP) vs. TA
0
25
Temperature [°C]
Temperature [°C]
0.0
-25
125
0.8
0.4
50
100
1.0
0.6
25
75
1.2
0.6
0
50
Figure 5. UVLO Start Threshold Voltage
(VSTART) vs. TA
Normalized
Normalized
Figure 4. Operating Supply Current (IOP) vs. TA
0.0
-25
25
Temperature [°C]
www.fairchildsemi.com
9
FSQ0565R, FSQ0765R — Green-Mode Farichild Power Switch (FPS™) for Quasi-Resonant Operation
Typical Performance Characteristics
1.2
Normalized
Normalized
These characteristic graphs are normalized at TA= 25°C.
1.0
0.8
1.2
1.0
0.8
0.6
0.6
0.4
0.4
0.2
0.2
0.0
-25
0
25
50
75
100
0.0
-25
125
0
1.2
1.0
0.8
0.4
0.2
0.2
75
100
0.0
-25
125
0
1.2
1.0
0.8
125
0.8
0.4
0.4
0.2
0.2
75
100
0.0
-25
125
Temperature [°C]
0
25
50
75
100
125
Temperature [°C]
Figure 14. Burst-Mode Low Threshold Voltage
(Vburl) vs. TA
Figure 15. Peak Current Limit (ILIM) vs. TA
© 2007 Fairchild Semiconductor Corporation
FSQ0565R, FSQ0765R Rev. 1.0.0
100
1.0
0.6
50
75
1.2
0.6
25
50
Figure 13. Burst-Mode High Threshold Voltage
(Vburh) vs. TA
Normalized
Normalized
Figure 12. Shutdown Delay Current (IDELAY) vs. TA
0
25
Temperature [°C]
Temperature [°C]
0.0
-25
125
0.8
0.4
50
100
1.0
0.6
25
75
1.2
0.6
0
50
Figure 11. Feedback Source Current (IFB) vs. TA
Normalized
Normalized
Figure 10. Blanking Time (tB) vs. TA
0.0
-25
25
Temperature [°C]
Temperature [°C]
www.fairchildsemi.com
10
FSQ0565R, FSQ0765R — Green-Mode Farichild Power Switch (FPS™) for Quasi-Resonant Operation
Typical Performance Characteristics (Continued)
1.2
Normalized
Normalized
These characteristic graphs are normalized at TA= 25°C.
1.0
0.8
1.2
1.0
0.8
0.6
0.6
0.4
0.4
0.2
0.2
0.0
-25
0
25
50
75
100
0.0
-25
125
0
1.2
1.0
0.8
0.4
0.2
0.2
75
100
0.0
-25
125
0
1.2
1.0
0.8
125
0.8
0.4
0.4
0.2
0.2
75
100
0.0
-25
125
Temperature [°C]
0
25
50
75
100
125
Temperature [°C]
Figure 20. Sync High Threshold Voltage 2
(VSH2) vs. TA
Figure 21. Sync Low Threshold Voltage 2
(VSL2) vs. TA
© 2007 Fairchild Semiconductor Corporation
FSQ0565R, FSQ0765R Rev. 1.0.0
100
1.0
0.6
50
75
1.2
0.6
25
50
Figure 19. Over-Voltage Protection (VOV) vs. TA
Normalized
Normalized
Figure 18. Shutdown Feedback Voltage (VSD) vs. TA
0
25
Temperature [°C]
Temperature [°C]
0.0
-25
125
0.8
0.4
50
100
1.0
0.6
25
75
1.2
0.6
0
50
Figure 17. Sync Low Threshold Voltage 1
(VSL1) vs. TA
Normalized
Normalized
Figure 16. Sync High Threshold Voltage 1
(VSH1) vs. TA
0.0
-25
25
Temperature [°C]
Temperature [°C]
www.fairchildsemi.com
11
FSQ0565R, FSQ0765R — Green-Mode Farichild Power Switch (FPS™) for Quasi-Resonant Operation
Typical Performance Characteristics (Continued)
2.2 Leading-Edge Blanking (LEB): At the instant the
internal SenseFET is turned on, a high-current spike
usually occurs through the SenseFET, caused by
primary-side capacitance and secondary-side rectifier
reverse recovery. Excessive voltage across the Rsense
resistor would lead to incorrect feedback operation in the
current-mode PWM control. To counter this effect, the
FPS employs a leading-edge blanking (LEB) circuit. This
circuit inhibits the PWM comparator for a short time
(tLEB) after the SenseFET is turned on.
1. Start-up: At start-up, an internal high-voltage current
source supplies the internal bias and charges the
external capacitor (Ca) connected to the VCC pin, as
illustrated in Figure 22. When VCC reaches 12V, the
FPS™ begins switching and the internal high-voltage
current source is disabled. The FPS continues its normal
switching operation and the power is supplied from the
auxiliary transformer winding unless VCC goes below the
stop voltage of 8V.
Vref
VCC
VDC
Idelay
VFB
VO
4
FOD817A
Ca
IFB
SenseFET
OSC
D1
CB
D2
3R
+
VFB*
3
VCC
6
Vstr
KA431
-
ICH
8V/12V
VCC good
FSQ0765R Rev.00
Gate
driver
R
OLP
VSD
Rsense
FSQ0765R Rev. 00
Vref
Figure 23. Pulse-Width-Modulation (PWM) Circuit
Internal
Bias
3. Synchronization: The FSQ-series employs a quasiresonant switching technique to minimize the switching
noise and loss. The basic waveforms of the quasiresonant converter are shown in Figure 24. To minimize
the MOSFET's switching loss, the MOSFET should be
turned on when the drain voltage reaches its minimum
value, which is indirectly detected by monitoring the VCC
winding voltage, as shown in Figure 24.
Figure 22. Start-up Circuit
2. Feedback Control: FPS employs current-mode
control, as shown in Figure 23. An opto-coupler (such as
the FOD817A) and shunt regulator (such as the KA431)
are typically used to implement the feedback network.
Comparing the feedback voltage with the voltage across
the Rsense resistor makes it possible to control the
switching duty cycle. When the reference pin voltage of
the shunt regulator exceeds the internal reference
voltage of 2.5V, the opto-coupler LED current increases,
pulling down the feedback voltage and reducing the duty
cycle. This typically happens when the input voltage is
increased or the output load is decreased.
Vds
VRO
VRO
VDC
tF
Vsync
Vovp (8V)
2.1 Pulse-by-Pulse Current Limit: Because currentmode control is employed, the peak current through the
SenseFET is limited by the inverting input of PWM
comparator (VFB*), as shown in Figure 23. Assuming
that the 0.9mA current source flows only through the
internal resistor (3R + R = 2.8k), the cathode voltage of
diode D2 is about 2.5V. Since D1 is blocked when the
feedback voltage (VFB) exceeds 2.5V, the maximum
voltage of the cathode of D2 is clamped at this voltage,
clamping VFB*. Therefore, the peak value of the current
through the SenseFET is limited.
1.2V
1.0V
230ns Delay
MOSFET Gate
ON
FSQ0765R Rev.00
Figure 24. Quasi-Resonant Switching Waveforms
© 2007 Fairchild Semiconductor Corporation
FSQ0565R, FSQ0765R Rev. 1.0.0
ON
www.fairchildsemi.com
12
FSQ0565R, FSQ0765R — Green-Mode Farichild Power Switch (FPS™) for Quasi-Resonant Operation
Functional Description
IDS
IDS
VDS
ingnore
4.4V
Vsync
1.2V
1.0V
internal delay
tX
tB=15μs
tX
tB=15μs
FSQ0765R Rev. 00
Figure 27. After Vsync Finds First Valley
IDS
4. Protection Circuits: The FSQ-series has several
self-protective functions, such as Overload Protection
(OLP), Abnormal Over-Current Protection (AOCP),
Over-Voltage Protection (OVP), and Thermal Shutdown
(TSD). All the protections are implemented as autorestart mode. Once the fault condition is detected,
switching is terminated and the SenseFET remains off.
This causes VCC to fall. When VCC falls down to the
Under-Voltage Lockout (UVLO) stop voltage of 8V, the
protection is reset and the start-up circuit charges the
VCC capacitor. When the VCC reaches the start voltage
of 12V, normal operation resumes. If the fault condition is
not removed, the SenseFET remains off and VCC drops
to stop voltage again. In this manner, the auto-restart can
alternately enable and disable the switching of the power
SenseFET until the fault condition is eliminated.
Because these protection circuits are fully integrated into
the IC without external components, the reliability is
improved without increasing cost.
IDS
VDS
4.4V
Vsync
1.2V
1.0V
internal delay
FSQ0765R Rev. 00
Figure 25. Vsync > 4.4V at tX
tX
tB=15μs
IDS
VDS
IDS
Power
on
Fault
occurs
Fault
removed
VDS
VCC
4.4V
Vsync
internal delay
12V
1.2V
1.0V
8V
FSQ0765R Rev. 00
FSQ0765R Rev. 00
Figure 26. Vsync < 4.4V at tX
Fault
situation
Normal
operation
t
Figure 28. Auto Restart Protection Waveforms
© 2007 Fairchild Semiconductor Corporation
FSQ0565R, FSQ0765R Rev. 1.0.0
Normal
operation
www.fairchildsemi.com
13
FSQ0565R, FSQ0765R — Green-Mode Farichild Power Switch (FPS™) for Quasi-Resonant Operation
The switching frequency is the combination of blank time
(tB) and detection time window (tW). In case of a heavy
load, the sync voltage remains flat after tB and waits for
valley detection during tW. This leads to a low switching
frequency not suitable for heavy loads. To correct this
drawback, additional timing is used. The timing
conditions are described in Figures 25, 26, and 27. When
the Vsync remains flat higher than 4.4V at the end of tB
that is tX, the next switching cycle starts after internal
delay time from tX. In the second case, the next switching
occurs on the valley when the Vsync goes below 4.4V
within tB. Once Vsync detects the first valley within tB, the
other switching cycle follows classical QRC operation.
OSC
PWM
LEB
250ns
S
Q
R
Q
Gate
driver
R
+
AOCP
-
VFB
3R
FSQ0765R Rev.00
R sense
2
GND
VOCP
Figure 30. Abnormal Over-Current Protection
4.3 Output-Short Protection (OSP): If the output is
shorted, steep current with extremely high di/dt can flow
through the SenseFET during the LEB time. Such a
steep current brings high voltage stress on drain of
SenseFET when turned off. To protect the device from
such an abnormal condition, OSP is included in the FSQseries. It is comprised of detecting VFB and SenseFET
turn-on time. When the VFB is higher than 2V and the
SenseFET turn-on time is lower than 1.2µs, the FPS
recognizes this condition as an abnormal error and shuts
down PWM switching until VCC reaches Vstart again. An
abnormal condition output short is shown in Figure 31.
MOSFET
Drain
Current
FSQ0765R Rev.00
Overload protection
6.0V
Rectifier
Diode Current
Turn-off delay
ILIM
VFB
0
2.5V
Minimum turn-on time
Vo
D
1.2us
output short occurs
t12= CFB*(6.0-2.5)/Idelay
0
t1
t2
t
Io
FSQ0765R Rev. 00
Figure 29. Overload Protection
0
Figure 31. Output Short Waveforms
4.2 Abnormal Over-Current Protection (AOCP): When
the secondary rectifier diodes or the transformer pins are
shorted, a steep current with extremely high di/dt can
flow through the SenseFET during the LEB time. Even
though the FSQ-series has overload protection, it is not
enough to protect the FSQ-series in that abnormal case,
since severe current stress is imposed on the SenseFET
until OLP triggers. The FSQ-series has an internal
AOCP circuit shown in Figure 30. When the gate turn-on
signal is applied to the power SenseFET, the AOCP
block is enabled and monitors the current through the
sensing resistor. The voltage across the resistor is
compared with a preset AOCP level. If the sensing
resistor voltage is greater than the AOCP level, the set
signal is applied to the latch, resulting in the shutdown of
the SMPS.
4.4 Over-Voltage Protection (OVP): If the secondaryside feedback circuit malfunctions or a solder defect
causes an opening in the feedback path, the current
through the opto-coupler transistor becomes almost
zero. VFB climbs up in a similar manner to the overload
situation, forcing the preset maximum current to be
supplied to the SMPS until the overload protection
triggers. Because more energy than required is provided
to the output, the output voltage may exceed the rated
voltage before the overload protection triggers, resulting
in the breakdown of the devices in the secondary side.
To prevent this situation, an OVP circuit is employed. In
general, the peak voltage of the sync signal is
proportional to the output voltage and the FSQ-series
© 2007 Fairchild Semiconductor Corporation
FSQ0565R, FSQ0765R Rev. 1.0.0
www.fairchildsemi.com
14
FSQ0565R, FSQ0765R — Green-Mode Farichild Power Switch (FPS™) for Quasi-Resonant Operation
4.1 Overload Protection (OLP): Overload is defined as
the load current exceeding its normal level due to an
unexpected abnormal event. In this situation, the
protection circuit should trigger to protect the SMPS.
However, even when the SMPS is in the normal
operation, the overload protection circuit can be
triggered during the load transition. To avoid this
undesired operation, the overload protection circuit is
designed to trigger only after a specified time to
determine whether it is a transient situation or a true
overload situation. Because of the pulse-by-pulse
current limit capability, the maximum peak current
through the SenseFET is limited, and therefore the
maximum input power is restricted with a given input
voltage. If the output consumes more than this maximum
power, the output voltage (VO) decreases below the set
voltage. This reduces the current through the optocoupler LED, which also reduces the opto-coupler
transistor current, thus increasing the feedback voltage
(VFB). If VFB exceeds 2.5V, D1 is blocked and the 5µA
current source starts to charge CB slowly up to VCC. In
this condition, VFB continues increasing until it reaches
6V, when the switching operation is terminated, as
shown in Figure 29. The delay time for shutdown is the
time required to charge CFB from 2.5V to 6V with 5µA. A
20 ~ 50ms delay time is typical for most applications.
VVcc_coil &VCC
FSQ0765R Rev.00
Absolue max VCC (20V)
VCC
VVcc_coil
VO
VOset
VDC
Npri
VFB
NVcc
0.55V
Improper OVP triggering
Vsync
0.35V
VOVP (8V)
tOVP
IDS
VSH2 (4.8V)
tOVP
VCLAMP
VDS
Figure 32. OVP Triggering
4.5 Thermal Shutdown with Hysteresis (TSD): The
SenseFET and the control IC are built in one package.
This makes it easy for the control IC to detect the
abnormally high temperature of the SenseFET. If the
temperature exceeds approximately 140°C, the thermal
shutdown triggers IC shutdown. The IC recovers its
operation when the junction temperature decreases
60°C from TSD temperature and VCC reaches start-up
voltage (Vstart).
time
FSQ0765R Rev.00
t2 t3
Switching
disabled
t4
Figure 33. Waveforms of Burst Operation
7. Switching Frequency Limit: To minimize switching
loss and Electromagnetic Interference (EMI), the
MOSFET turns on when the drain voltage reaches its
minimum value in quasi-resonant operation. However,
this causes switching frequency to increases at light load
conditions. As the load decreases or input voltage
increases, the peak drain current diminishes and the
switching frequency increases. This results in severe
switching losses at light-load condition, as well as
intermittent switching and audible noise. These problems
create limitations for the quasi-resonant converter
topology in a wide range of applications.
5. Soft-Start: The FPS has an internal soft-start circuit
that increases PWM comparator inverting input voltage
with the SenseFET current slowly after it starts up. The
typical soft-start time is 15ms. The pulse width to the
power switching device is progressively increased to
establish the correct working conditions for transformers,
inductors, and capacitors. The voltage on the output
capacitors is progressively increased with the intention of
smoothly establishing the required output voltage. This
mode helps prevent transformer saturation and reduces
stress on the secondary diode during start-up.
To overcome these problems, FSQ-series employs a
frequency-limit function, as shown in Figures 34 and 35.
Once the SenseFET is turned on, the next turn-on is
prohibited during the blanking time (tB). After the
blanking time, the controller finds the valley within the
detection time window (tW) and turns on the MOSFET, as
shown in Figures 34 and Figure 35 (Cases A, B, and C).
© 2007 Fairchild Semiconductor Corporation
FSQ0565R, FSQ0765R Rev. 1.0.0
t1
Switching
disabled
www.fairchildsemi.com
15
FSQ0565R, FSQ0765R — Green-Mode Farichild Power Switch (FPS™) for Quasi-Resonant Operation
6. Burst Operation: To minimize power dissipation in
standby mode, the FPS enters burst-mode operation. As
the load decreases, the feedback voltage decreases. As
shown in Figure 33, the device automatically enters
burst-mode when the feedback voltage drops below
VBURL (350mV). At this point, switching stops and the
output voltages start to drop at a rate dependent on
standby current load. This causes the feedback voltage
to rise. Once it passes VBURH (550mV), switching
resumes. The feedback voltage then falls and the
process repeats. Burst-mode operation alternately
enables and disables switching of the power SenseFET,
thereby reducing switching loss in standby mode.
uses a sync signal instead of directly monitoring the
output voltage. If the sync signal exceeds 8V, an OVP is
triggered, shutting down the SMPS. To avoid undesired
triggering of OVP during normal operation, there are two
points considered, as depicted in Figure 32. The peak
voltage of the sync signal should be designed below 6V
and the spike of the SYNC pin must be as low as
possible to avoid getting longer than tOVP by decreasing
the leakage inductance shown at VCC winding coil.
Internally, quasi-resonant operation is divided into two
categories; one is first valley switching and the other is
second-valley switching after blanking time. In AVS, two
successive occurrences of first-valley switching and the
other two successive occurrences of second-valley
switching is alternatively selected to maximize frequency
modulation. As depicted in Figure 35, the switching
frequency hops when the input voltage is high. The
internal timing diagram of AVS is described in Figure 36.
Figure 35. Switching Frequency Range
Figure 34. QRC Operation with Limited Frequency
Figure 36. Alternating Valley Switching (AVS)
© 2007 Fairchild Semiconductor Corporation
FSQ0565R, FSQ0765R Rev. 1.0.0
www.fairchildsemi.com
16
FSQ0565R, FSQ0765R — Green-Mode Farichild Power Switch (FPS™) for Quasi-Resonant Operation
8. AVS (Alternating Valley Switching): Due to the
quasi-resonant operation with limited frequency, the
switching frequency varies depending on input voltage,
load transition, and so on. At high input voltage, the
switching on time is relatively small compared to low
input voltage. The input voltage variance is small and the
switching frequency modulation width becomes small. To
improve the EMI performance, AVS is enabled when
input voltage is high and the switching on time is small.
If no valley is found during tW, the internal SenseFET is
forced to turn on at the end of tW (Case D). Therefore,
the devices have a minimum switching frequency of
48kHz and a maximum switching frequency of 67kHz.
Due to the combined scheme, FPS shows better noise
immunity than conventional PWM controller and
MOSFET discrete solution. Further more, internal drain
current sense eliminates the possibility of noise
generation caused by a sensing resistor. There are some
recommendations for PCB layout to enhance noise
immunity and suppress natural noise inevitable in powerhandling components.
There are typically two grounds in the conventional
SMPS: power ground and signal ground. The power
ground is the ground for primary input voltage and
power, while the signal ground is ground for PWM
controller. In FPS, those two grounds share the same
pin, GND. Normally the separate grounds do not share
the same trace and meet only at one point, the GND pin.
More, wider patterns for both grounds are good for large
currents by decreasing resistance.
Capacitors at the VCC and FB pins should be as close
as possible to the corresponding pins to avoid noise from
the switching device. Sometimes Mylar® or ceramic
capacitors with electrolytic for VCC is better for smooth
operation. The ground of these capacitors needs to
connect to the signal ground (not power ground).
Figure 37. Recommended PCB Layout
The cathode of the snubber diode should be close to the
drain pin to minimize stray inductance. The Y-capacitor
between primary and secondary should be directly
connected to the power ground of DC link to maximize
surge immunity.
Because the voltage range of feedback and sync line is
small, it is affected by the noise of the drain pin. Those
traces should not draw across or close to the drain line.
When the heat sink is connected to the ground, it should
be connected to the power ground. If possible, avoid
using jumper wires for power ground and drain.
Mylar® is a registered trademark of DuPont Teijin Films.
© 2007 Fairchild Semiconductor Corporation
FSQ0565R, FSQ0765R Rev. 1.0.0
www.fairchildsemi.com
17
FSQ0565R, FSQ0765R — Green-Mode Farichild Power Switch (FPS™) for Quasi-Resonant Operation
PCB Layout Guide
Application
FPS™ Device
Input Voltage
Range
Rated Output Power
Output Voltage
(Maximum Current)
LCD Monitor
Power Supply
FSQ0565R
85-265VAC
46W
5.1V (2.0A)
12V (3.0A)
Features
„ Average efficiency of 25%, 50%, 75%, and 100% load conditions is higher than 80% at universal input
„ Low standby mode power consumption (<1W at 230VAC input and 0.5W load)
„ Reduce EMI noise through valley switching operation
„ Enhanced system reliability through various protection functions
„ Internal soft-start (15ms)
Key Design Notes
„ The delay time for overload protection is designed to be about 23ms with C105 of 33nF. If faster/slower triggering of
OLP is required, C105 can be changed to a smaller/larger value (e.g. 100nF for 70ms).
„ The input voltage of VSync must be between 4.7V and 8V just after MOSFET turn-off to guarantee hybrid control and
to avoid OVP triggering during normal operation.
„ The SMD-type 100nF capacitor must be placed as close as possible to VCC pin to avoid malfunction by abrupt pul-
sating noises and to improve surge immunity.
1. Schematic
FSQ0765R Rev.00
D201
T1
MBRF10H100
EER3016
BD101
2KBP06M3N257
2
C104
4.7nF
630V
R103
33kΩ
1W
C103
100μF
400V
D101
1N 4007
C202
1000μF
25V
C201
1000μF
25V
8
2
R104
20Ω
0.5W
12V, 3A
10
1
R102
68kΩ
L201
5μH
3
FSQ0565R
1
6
3
C105
33nF
100V
C102
150nF
275VAC
Drain
1
R105 C106 C107
100Ω 100nF 47μF
Vcc 0.5W SMD 50V
4
3
Vfb
GND
D102
UF 4004 R107
2
18kΩ
5
4
Vstr
D202
MBRF1060
Sync
4
LF101
34mH
R108
12kΩ
5V, 2A
7
C204
1000μF
10V
C203
1000μF
10V
6
5
ZD101
1N4745A
L202
5μH
C301
4.7nF
1kV
R201
1kΩ
R101
2MΩ
1W
R202
1.2kΩ
Optional components
RT1
5D-9
C101
150nF
275VAC
IC301
FOD817A
F1
FUSE
250V
2A
IC201
KA431
R204
4kΩ
R203
1.2kΩ
C205
47nF
R205
4kΩ
Figure 38. Demo Circuit of FSQ0565R
© 2007 Fairchild Semiconductor Corporation
FSQ0565R, FSQ0765R Rev. 1.0.0
www.fairchildsemi.com
18
FSQ0565R, FSQ0765R — Green-Mode Farichild Power Switch (FPS™) for Quasi-Resonant Operation
Typical Application Circuit
FSQ0765R Rev.00
EER3016
1
TAPE 4T
FSQ0765R Rev.00
1
10 N /2
12V
Lp/2
L12V/2
Np/2
Np/2
Na
2
3
L5V
7
(TIW 0.5φ,
2parallel)
N5V
8
TAPE 2T
5
7
TAPE 2T
6
6
TAPE 2T
10
(TIW 0.5φ,
2parallel)
10
9
9
TAPE 2T
2
Lp/2
TAPE 1T
3
(0.4φ)
5
8
4
L12V/2
7
9
LVcc(0.2φ)
8
4
TAPE 2T
9
(TIW 0.5φ,
2parallel)
9 N /2
12V
TAPE 1T
2
(0.4φ)
6
Bottom of bobbin
Figure 39. Transformer Schematic Diagram of FSQ0565R
3. Winding Specification
Position
Top
No
Pin (s→f)
Wire
Turns
Winding Method
Insulation: Polyester Tape t = 0.025mm, 4 Layers
Np/2
0.4φ × 1
2→1
20
2-Layer Solenoid Winding
4
Center Solenoid Winding
10
Center Solenoid Winding
4
Center Solenoid Winding
5
Center Solenoid Winding
32
2-Layer Solenoid Winding
Insulation: Polyester Tape t = 0.025mm, 2 Layers
N12V/2
0.5φ × 2(TIW)
9→8
Insulation: Polyester Tape t = 0.025mm, 2 Layers
Na
0.15φ × 1
4→5
Insulation: Polyester Tape t = 0.025mm, 2 Layers
N5V
0.5φ × 2(TIW)
7→6
Insulation: Polyester Tape t = 0.025mm, 2 Layers
N12V/2
0.5φ × 2(TIW)
10 → 9
Insulation: Polyester Tape t = 0.025mm, 2 Layers
Bottom
Np/2
0.4φ × 1
3→2
4. Electrical Characteristics
Pin
Specification
Remarks
Inductance
1-3
360µH ± 10%
100kHz, 1V
Leakage
1-3
15µH Maximum
Short all other pins
5. Core & Bobbin
„ Core: EER3016 (Ae=109.7mm2)
„ Bobbin: EER3016
© 2007 Fairchild Semiconductor Corporation
FSQ0565R, FSQ0765R Rev. 1.0.0
www.fairchildsemi.com
19
FSQ0565R, FSQ0765R — Green-Mode Farichild Power Switch (FPS™) for Quasi-Resonant Operation
2. Transformer
Part
Value
Note
Resistor
Part
Value
Note
C205
47nF/50V
Ceramic Capacitor
C301
4.7nF/1kV
Ceramic Capacitor
R101
2MΩ
1W
R102
68kΩ
1/2W
R103
33kΩ
1W
L201
5µH
5A Rating
R104
20Ω
1W
L202
5µH
5A Rating
R105
100Ω
optional, 1/4W
R107
18kΩ
1/4W
D101
IN4007
1A, 1000V General-Purpose
Rectifier
R108
12kΩ
1/4W
D102
UF4004
1A, 400V Ultrafast Rectifier
R201
1kΩ
1/4W
ZD101
1N4745A
1W 16V Zener Diode
(optional)
R202
1.2kΩ
1/4W
D201
MBRF10H100
10A,100V Schottky Rectifier
R203
1.2kΩ
1/4W
D202
MBRF1060
R204
5.2kΩ
1/4W
R205
4.7kΩ
1/4W
Capacitor
C101
150nF/275VAC
Box Capacitor
C102
150nF/275VAC
Box Capacitor
C103
100µF/400V
Electrolytic Capacitor
C104
4.7nF/630V
Film Capacitor
C105
33nF/50V
Ceramic Capacitor
C106
100nF/50V
SMD (1206)
C107
47µF/50V
Electrolytic Capacitor
C201
1000µF/25V
Low ESR Electrolytic
Capacitor
C202
1000µF/25V
Low ESR Electrolytic
Capacitor
C203
1000µF/10V
Low ESR Electrolytic
Capacitor
C204
1000µF/10V
Low ESR Electrolytic
Capacitor
Inductor
Diode
IC101
FSQ0565R
FPS™
IC201
KA431 (TL431)
Voltage Reference
IC202
FOD817A
Opto-Coupler
Fuse
Fuse
2A/250V
NTC
RT101
5D-9
Bridge Diode
BD101
2KBP06M2N257
Bridge Diode
Line Filter
LF101
34mH
Transformer
T1
© 2007 Fairchild Semiconductor Corporation
FSQ0565R, FSQ0765R Rev. 1.0.0
10A,60V Schottky Rectifier
IC
EER3016
Ae=109.7mm2
www.fairchildsemi.com
20
FSQ0565R, FSQ0765R — Green-Mode Farichild Power Switch (FPS™) for Quasi-Resonant Operation
6. Demo Board Part List
FSQ0565R, FSQ0765R — Green-Mode Farichild Power Switch (FPS™) for Quasi-Resonant Operation
Package Dimensions
TO-220F-6L (Forming)
MKT-TO220A06revB
Figure 40. 6-Lead, TO-220 Package
© 2007 Fairchild Semiconductor Corporation
FSQ0565R, FSQ0765R Rev. 1.0.0
www.fairchildsemi.com
21
®
ACEx
Build it Now¥
CorePLUS¥
CROSSVOLT¥
CTL™
Current Transfer Logic™
®
EcoSPARK
®
®
Fairchild
®
Fairchild Semiconductor
FACT Quiet Series™
®
FACT
®
FAST
FastvCore¥
FPS¥
®
FRFET
SM
Global Power Resource
®
Power247
®
POWEREDGE
Power-SPM¥
®
PowerTrench
Programmable Active Droop¥
®
QFET
QS¥
QT Optoelectronics¥
Quiet Series¥
RapidConfigure¥
SMART START¥
®
SPM
STEALTH™
SuperFET¥
SuperSOT¥-3
SuperSOT¥-6
Green FPS¥
Green FPS¥ e-Series¥
GTO¥
i-Lo¥
IntelliMAX¥
ISOPLANAR¥
MegaBuck™
MICROCOUPLER¥
MicroFET¥
MicroPak¥
MillerDrive™
Motion-SPM™
®
OPTOLOGIC
®
OPTOPLANAR
®
PDP-SPM™
®
Power220
SuperSOT¥-8
SyncFET™
®
The Power Franchise
TinyBoost¥
TinyBuck¥
®
TinyLogic
TINYOPTO¥
TinyPower¥
TinyPWM¥
TinyWire¥
PSerDes¥
®
UHC
UniFET¥
VCX¥
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. THESE SPECIFICATIONS DO NOT EXPAND THE TERMS OF FAIRCHILD’S
WORLDWIDE TERMS AND CONDITIONS, SPECIFICALLY THE WARRANTY THEREIN, WHICH COVERS THESE PRODUCTS.
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, and (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 a significant injury of the user.
2. A critical component in 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
Advance Information
Formative or In Design
This datasheet contains the design specifications for product
development. Specifications may change in any manner without notice.
Definition
Preliminary
First Production
This datasheet contains preliminary data; supplementary data will be
published at a later date. Fairchild Semiconductor reserves the right to
make changes at any time without notice to improve design.
No Identification Needed
Full Production
This datasheet contains final specifications. Fairchild Semiconductor
reserves the right to make changes at any time without notice to improve
design.
Obsolete
Not In Production
This datasheet contains specifications on a product that has been
discontinued by Fairchild Semiconductor. The datasheet is printed for
reference information only.
Rev. I31
© 2007 Fairchild Semiconductor Corporation
FSQ0565R, FSQ0765R Rev. 1.0.0
www.fairchildsemi.com
22
FSQ0565R, FSQ0765R — Green-Mode Farichild Power Switch (FPS™) for Quasi-Resonant Operation
TRADEMARKS
The following are registered and unregistered trademarks and service marks Fairchild Semiconductor owns or is authorized to use and is not
intended to be an exhaustive list of all such trademarks.