FAIRCHILD FSBH0170NY_F116

FSBH0F70A _F116, FSBH0170_F116,
FSBH0270_F116, FSBH0370_F116
Green Mode Fairchild Power Switch (FPS™)
Features
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Description
Brownout Protection with Hysteresis
The highly integrated FSBH-series consists of an
integrated current-mode Pulse Width Modulator (PWM)
and an avalanche-rugged 700V SenseFET. It is
specifically designed for high-performance offline
Switched-Mode Power Supplies (SMPS) with minimal
external components.
Built-In 5ms Soft-Start Function
Internal Avalanche-Rugged 700V SenseFET
Low Acoustic Noise During Light-Load Operation
High-Voltage Startup
The integrated PWM controller features include a
proprietary green-mode function that provides off-time
modulation to linearly decrease the switching frequency
at light-load conditions to minimize standby power
consumption. To avoid acoustic-noise problems, the
minimum PWM frequency is set above 18kHz. This
green-mode function enables the power supply to meet
international power conservation requirements. The
PWM controller is manufactured using the BiCMOS
process to further reduce power consumption. The
FSBH-series turns off some internal circuits to improve
power saving when VFB is lower than 1.6V, which allows
an operating current of only 2.5mA.
Linearly Decreasing PWM Frequency to 18KHz
Peak-Current-Mode Control
Cycle-by-Cycle Current Limiting
Leading-Edge Blanking (LEB)
Synchronized Slope Compensation
Internal Open-Loop Protection
VDD Under-Voltage Lockout (UVLO)
VDD Over-Voltage Protection (OVP)
Internal Auto-Restart Circuit (OVP, OTP)
The FSBH-series has built-in synchronized slope
compensation to achieve stable peak-current-mode
control. The proprietary external line compensation
ensures constant output power limit over a wide AC
input voltage range, from 90VAC to 264VAC.
Constant Power Limit (Full AC Input Range)
Internal OTP Sensor with Hysteresis
VIN Pin for Pull-HIGH Latch Function and
Pull-LOW Auto-Recovery Protection
The FSBH-series provides many protection functions. In
addition to cycle-by-cycle current limiting, the internal
open-loop protection circuit ensures safety when an
open-loop or output short occurs. PWM output is
disabled until VDD drops below the VTH-OLP, then the
controller starts up again. As long as VDD exceeds 28V,
the internal OVP circuit is triggered.
Applications
General-purpose switched-mode power supplies and
flyback power converters, including:


Auxiliary Power Supply for PC and Server

Adapter for Camcorder
SMPS for VCR, SVR, STB, DVD & DVCD Player,
Printer, Facsimile, and Scanner
© 2010 Fairchild Semiconductor Corporation
FSBH0F70A_F116, FSBH0170/0270/0370_F116 • Rev. 1.0.1
Compared with a discrete MOSFET and controller or
RCC switching converter solution, the FSBH-series
reduces component count, design size, and weight;
while increasing efficiency, productivity, and system
reliability. These devices provide a basic platform that is
well suited for the design of cost-effective flyback
converters, such as in PC auxiliary power supplies.
www.fairchildsemi.com
1
FSBH0F70A_F116, FSBH0170/0270/0370_F116 — Green Mode Fairchild Power Switch (FPS™)
April 2011
Part Number
SenseFET
VIN Pin
(PIN #4)
FSBH0F70ANY_F116
0.5A 700V
Not Available
FSBH0170NY_F116
1.0A 700V
FSBH0270NY_F116
2.0A 700V
FSBH0370NY_F116
3.0A 700V
Operating
Temperature Range
Package
Packing
Method
-40°C to +105°C
8-Pin, Dual In-Line
Package (DIP)
Tube
Enabled
Typical Application Diagram
HV
Drain
VIN
FB
Figure 1.
VDD
GND
Typical Flyback Application
Output Power Table(1)
Product
FSBH0F70A_F116
230VAC ± 15%(2)
Adapter
(3)
7W
85-265VAC
Open Frame
10W
(4)
Adapter
6W
(3)
Open Frame(4)
8W
FSBH0170_F116
10W
15W
9W
13W
FSBH0270_F116
14W
20W
11W
16W
FSBH0370_F116
17.5W
25W
13W
19W
Notes:
1. The maximum output power can be limited by junction temperature.
2. 230 VAC or 100/115 VAC with doublers.
3. Typical continuous power in a non-ventilated enclosed adapter with sufficient drain pattern as a heat sink at 50C
ambient.
4. Maximum practical continuous power in an open-frame design with sufficient drain pattern as a heat sink at 50C
ambient.
© 2010 Fairchild Semiconductor Corporation
FSBH0F70A_F116, FSBH0170/0270/0370_F116 • Rev. 1.0.1
www.fairchildsemi.com
2
FSBH0F70A_F116, FSBH0170/0270/0370_F116 — Green Mode Fairchild Power Switch (FPS™)
Ordering Information
FSBH0F70A_F116, FSBH0170/0270/0370_F116 — Green Mode Fairchild Power Switch (FPS™)
Block Diagram
Figure 2.
FSBH0170/0270/0370_F116 Internal Block Diagram
Figure 3.
FSBH0F70A_F116 Internal Block Diagram
© 2010 Fairchild Semiconductor Corporation
FSBH0F70A_F116, FSBH0170/0270/0370_F116 • Rev. 1.0.1
www.fairchildsemi.com
3
F – Fairchild Logo
Z – Plant Code
X – 1-Digit Year Code
Y – 1-Digit Week Code
TT – 2-Digit Die-Run Code
T – Package Type (N:DIP)
P – Y: Green Package
M – Manufacture Flow Code
Figure 4.
Pin Configuration and Top Mark Information
Pin Definitions
Pin #
Name
1
GND
Ground. SenseFET source terminal on primary side and internal controller ground.
2
VDD
Power Supply. The internal protection circuit disables PWM output as long as VDD exceeds the
OVP trigger point.
3
FB
Feedback. The signal from the external compensation circuit is fed into this pin. The PWM duty
cycle is determined in response to the signal on this pin and the internal current-sense signal.
VIN
Line-Voltage Detection. The line-voltage detection is used for brownout protection with
hysteresis and constant output power limit over universal AC input range. This pin has additional
protections that are pull-HIGH latch and pull-LOW auto recovery, depending on the application.
4
Description
NC
No Connection. FSBH0F70A_F116
5
HV
Startup. For startup, this pin is pulled HIGH to the line input or bulk capacitor via resistors.
6
Drain
SenseFET Drain. High-voltage power SenseFET drain connection.
7
Drain
SenseFET Drain. High-voltage power SenseFET drain connection.
8
Drain
SenseFET Drain. High-voltage power SenseFET drain connection.
© 2010 Fairchild Semiconductor Corporation
FSBH0F70A_F116, FSBH0170/0270/0370_F116 • Rev. 1.0.1
www.fairchildsemi.com
4
FSBH0F70A_F116, FSBH0170/0270/0370_F116 — Green Mode Fairchild Power Switch (FPS™)
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.
Symbol
VDRAIN
IDM
EAS
Parameter
Min.
(5,6)
Drain Pin Voltage
Drain Current Pulsed(7)
Single Pulsed Avalanche Energy(8)
Max.
Unit
V
FSBH0x70/A_F116
700
FSBH0F70A_F116
1.5
FSBH0170_F116
4.0
FSBH0270_F116
8.0
FSBH0370_F116
12.0
A
FSBH0F70A_F116
10
FSBH0170_F116
50
FSBH0270_F116
140
FSBH0370_F116
230
VDD
DC Supply Voltage
VFB
FB Pin Input Voltage
-0.3
-0.3
mJ
30
V
7.0
V
VIN
VIN Pin Input Voltage
7.0
V
VHV
HV Pin Input Voltage
700
V
PD
Power Dissipation (TA＜50°C)
1.5
W
ΘJA
Junction-to-Air Thermal Resistance
80
C/W
ψJT
TJ
TSTG
TL
Junction-to-Top Thermal Resistance
(9)
C/W
20
Operating Junction Temperature
Internally limited
Storage Temperature Range
-55
Lead Temperature (Wave Soldering or IR, 10 Seconds)
Human Body Model
(All Pins Except HV pin): JESD22-A114
ESD
Charged Device Model
(All Pins Except HV pin): JESD22-C101
FSBH0F70A_F116
5.0
FSBH0170_F116
5.0
FSBH0270_F116
5.0
FSBH0370_F116
5.0
FSBH0F70A_F116
2.0
FSBH0170_F116
2.0
FSBH0270_F116
2.0
FSBH0370_F116
1.5
(10)
C
+150
C
+260
C
kV
Notes:
5. All voltage values, except differential voltages, are given with respect to the network ground terminal.
6. Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device.
7. Non-repetitive rating: pulse width is limited by maximum junction temperature.
8. L = 51mH, starting TJ = 25C.
9. Measured on the package top surface.
10. Internally Limited of TJ refers to TOTP
Recommended Operating Conditions
The Recommended Operating Conditions table defines the conditions for actual device operation. Recommended
operating conditions are specified to ensure optimal performance to the datasheet specifications. Fairchild does not
recommend exceeding them or designing to Absolute Maximum Ratings.
Symbol
TA
Parameter
Operating Ambient Temperature
© 2010 Fairchild Semiconductor Corporation
FSBH0F70A_F116, FSBH0170/0270/0370_F116 • Rev. 1.0.1
Min.
Max.
Unit
-40
+105
°C
www.fairchildsemi.com
5
FSBH0F70A_F116, FSBH0170/0270/0370_F116 — Green Mode Fairchild Power Switch (FPS™)
Absolute Maximum Ratings
VDD=15V and TA=25C unless otherwise specified.
Symbol
Parameter
Condition
Min.
Typ.
Max.
Unit
SenseFET Section
BVDSS
Drain-Source
Breakdown Voltage
IDSS
Zero-Gate-Voltage
Drain Current
RDS(ON)
CISS
COSS
CRSS
tD(ON)
tR
tD(OFF)
tF
Drain-Source OnState Resistance(12)
Input Capacitance
Output Capacitance
Reverse Transfer
Capacitance
Turn-On Delay
Rise Time
Turn-Off Delay
Fall Time
VDS=700V, VGS=0V
700
V
VDS=700V, VGS=0V
50
VDS=560V, VGS=0V, TC=125C
200
VGS=10V, ID=0.5A
VGS=0V, VDS=25V,
f=1MHz
VGS=0V, VDS=25V,
f=1MHz
VGS=0V, VDS=25V,
f=1MHz
VDS=350V, ID=1.0A
VDS=350V, ID=1.0A
VDS=350V, ID=1.0A
VDS=350V, ID=1.0A
FSBH0F70A_F116
14.00
19.00
FSBH0170_F116
8.80
11.00
FSBH0270_F116
6.00
7.20
FSBH0370_F116
4.00
4.75
FSBH0F70A_F116
162
211
FSBH0170_F116
250
325
FSBH0270_F116
550
715
FSBH0370_F116
315
410
FSBH0F70A_F116
18
24
FSBH0170_F116
25
33
FSBH0270_F116
38
50
FSBH0370_F116
47
61
FSBH0F70A_F116
3.8
5.7
FSBH0170_F116
10.0
15.0
FSBH0270_F116
17.0
26.0
FSBH0370_F116
9.0
24.0
FSBH0F70A_F116
9.5
29.0
FSBH0170_F116
12.0
34.0
FSBH0270_F116
20.0
50.0
FSBH0370_F116
11.2
33.0
FSBH0F70A_F116
19
48
FSBH0170_F116
4
18
FSBH0270_F116
15
40
FSBH0370_F116
34
78
FSBH0F70A_F116
33.0
76.0
FSBH0170_F116
30.0
70.0
FSBH0270_F116
55.0
120.0
FSBH0370_F116
28.2
67.0
FSBH0F70A_F116
42
94
FSBH0170_F116
10
30
FSBH0270_F116
25
60
FSBH0370_F116
32
74
μA
Ω
pF
pF
pF
ns
ns
ns
ns
Continued on the following page…
© 2010 Fairchild Semiconductor Corporation
FSBH0F70A_F116, FSBH0170/0270/0370_F116 • Rev. 1.0.1
www.fairchildsemi.com
6
FSBH0F70A_F116, FSBH0170/0270/0370_F116 — Green Mode Fairchild Power Switch (FPS™)
Electrical Characteristics
VDD=15V and TA=25C unless otherwise specified.
Symbol
Parameter
Condition
Min.
Typ.
Max.
Unit
Control Section
VDD Section
VDD-ON
Start Threshold Voltage
11
12
13
V
VDD-OFF
Minimum Operating Voltage
7
8
9
V
FSBH0170_F116
IDD-ST
Startup Current
FSBH0270_F116
VDD-ON – 0.16V
30
FSBH0370_F116
FSBH0F70A_F116
VDD-ON – 0.16V
240
320
400
µA
IDD-OP
Operating Supply Current
VDD=15V, VFB=3V
3.0
3.5
4.0
mA
IDD-ZDC
Operating Current for VFB<VFB-ZDC
VDD=12V, VFB=1.6V
1.5
2.5
3.5
mA
IDD-OLP
Internal Sink Current
VTH-OLP+0.1V
30
70
90
µA
VTH-OLP
IDD-OLP Off Voltage
5
6
7
V
VDD-OVP
VDD Over-Voltage Protection
27
28
29
V
VDD Over-Voltage Protection Debounce Time
75
130
200
µs
1.5
3.5
5.0
mA
1
20
µA
94
100
106
kHz
14
18
22
kHz
tD-VDD-OVP
HV Section
IHV
IHV-LC
Maximum Current Drawn from HV Pin
HV 120VDC,
VDD=0V with 10µF
Leakage Current after Startup
HV=700V,
VDD=VDD-OFF+1V
Oscillator Section
fOSC
Frequency in Nominal Mode
fOSC-G
Green-Mode Frequency
DMAX
Maximum Duty Cycle
Center Frequency
85
%
fDV
Frequency Variation vs. VDD Deviation
VDD=11V to 22V
5
%
fDT
Frequency Variation vs. Temperature
Deviation(11)
TA=-25 to 85C
5
%
VIN Section
VIN-ON
PWM Turn-On Threshold Voltage
1.08
1.13
1.18
V
VIN-OFF
PWM Turn-Off Threshold Voltage
0.50
0.55
0.60
V
tIN-OFF
PWM Turn-Off Debounce Time
VIN-H
Pull-HIGH Latch Trigger Level
tIN-H
Pull-HIGH Latch Debounce Time
VIN-L
Pull-LOW Auto-Recovery Trigger Level
500
4.4
4.7
ms
5.0
100
V
µs
0.2
0.3
0.4
V
1/4.5
1/4.0
1/3.5
V/V
7
kΩ
Feedback Input Section
AV
FB Voltage to Current-Sense Attenuation
ZFB
Input Impedance
VFB-OPEN
Output High Voltage
4
FB Pin Open
5.5
V
Continued on the following page…
© 2010 Fairchild Semiconductor Corporation
FSBH0F70A_F116, FSBH0170/0270/0370_F116 • Rev. 1.0.1
www.fairchildsemi.com
7
FSBH0F70A_F116, FSBH0170/0270/0370_F116 — Green Mode Fairchild Power Switch (FPS™)
Electrical Characteristics (Continued)
VDD=15V and TA=25C unless otherwise specified.
Symbol
Parameter
Condition
Min.
Typ.
Max.
Unit
VFB-N
Green-Mode Entry FB Voltage
2.3
2.5
2.7
V
VFB-G
Green-Mode Ending FB Voltage
1.9
2.0
2.1
V
VFB-ZDC
Zero Duty Cycle FB Voltage
VFB-OLP
FB Open-Loop
Trigger Level
tD-OLP
1.6
V
FSBH0F70A_F116
5.2
5.4
5.6
FSBH0x70_F116
4.4
4.6
4.8
50
56
59
FB Open-Loop Protection Delay
V
ms
(15)
Current-Sense Section
ILIM
tSS
Peak Current
Limit
FSBH0F70A_F116
VIN Open
0.63
0.73
0.83
FSBH0170_F116
VIN=1.2V
0.70
0.80
0.90
FSBH0270_F116
VIN=1.2V
0.90
1.00
1.10
FSBH0370_F116
VIN=1.2V
1.10
1.20
1.30
4.5
5.0
5.5
(11)
Period During Soft-Start Time
A
ms
Constant Power Limit (FSBH0170, FSBH0270, FSBH0370)
VLMT1
Threshold Voltage 1 for Current Limit
VIN=1.2V
0.73
0.80
0.87
V
VLMT2
Threshold Voltage 2 for Current Limit
VIN=3.6V
0.56
0.63
0.70
V
0.97
1.00
1.03
V
+135
+142
+150
°C
Constant Power Limit (FSBH0F70A)
VLMT
Threshold Voltage for Current Limit
Over-Temperature Protection Section (OTP)
TOTP
TRESTART
Protection Junction Temperature(11,13)
(11,14)
Restart Junction Temperature
TOTP-25
°C
Notes:
11. These parameters, although guaranteed, are not 100% tested in production.
12. Pulse test: pulse width ≤ 300µs, duty ≤ 2%.
13. When activated, the output is disabled and the latch is turned off.
14. The threshold temperature for enabling the output again and resetting the latch after over-temperature protection
has been activated.
15. These parameters, although guaranteed, are tested in wafer process.
Figure 5.
© 2010 Fairchild Semiconductor Corporation
FSBH0F70A_F116, FSBH0170/0270/0370_F116 • Rev. 1.0.1
VFB vs. PWM Frequency
www.fairchildsemi.com
8
FSBH0F70A_F116, FSBH0170/0270/0370_F116 — Green Mode Fairchild Power Switch (FPS™)
Electrical Characteristics (Continued)
FSBH0F70A_F116, FSBH0170/0270/0370_F116 — Green Mode Fairchild Power Switch (FPS™)
Typical Characteristics
14
3.02
12
3.00
2.98
2.96
IDD-OP(µA)
ID D-ST(µA)
10
8
6
2.94
2.92
4
2.90
2
2.88
0
2.86
-40
-25
-10
5
20
35
50
65
80
95
110
125
-40
-25
-10
5
20
Temperature(°C)
IDD-ST vs. Temperature
Figure 7.
12.4
8.3
12.2
8.2
12.0
8.1
V DD-OFF (V)
V DD-ON (V)
Figure 6.
11.8
11.6
11.4
65
80
95
110
125
110
125
110
125
IDD-OP vs. Temperature
8.0
7.9
7.7
-40
-25
-10
5
20
35
50
65
80
95
110
125
-40
-25
-10
5
20
Temperature(°C)
Figure 8.
35
50
65
80
95
Temperature(°C)
VDD-ON vs. Temperature
Figure 9.
6.6
28.42
6.4
28.41
6.2
VDD-OFF vs. Temperature
28.40
V D D-OVP(V)
V TH-OLP(V)
50
7.8
11.2
6.0
5.8
5.6
28.39
28.38
28.37
5.4
28.36
5.2
5.0
28.35
-40
-25
-10
5
20
35
50
65
80
95
110
125
-40
-25
-10
5
Temperature(°C)
Figure 10.
20
35
50
65
80
95
Temperature(°C)
VTH-OLP vs. Temperature
Figure 11.
4.0
7
3.5
6
VDD-OVP vs. Temperature
5
IHV-LC(µA)
3.0
IHV(mA)
35
Temperature(°C)
2.5
2.0
4
3
2
1.5
1
1.0
0
-40
-25
-10
5
20
35
50
65
80
95
110
125
-40
-25
-10
Temperature(°C)
Figure 12.
20
35
50
65
80
95
110
125
Temperature(°C)
IHV vs. Temperature
© 2010 Fairchild Semiconductor Corporation
FSBH0F70A_F116, FSBH0170/0270/0370_F116 • Rev. 1.0.1
5
Figure 13.
IHV-LC vs. Temperature
www.fairchildsemi.com
9
101.5
19.2
101.0
19.1
F OSC -G (kHz)
FOSC (kHz)
100.5
100.0
99.5
99.0
19.0
18.9
18.8
98.5
18.7
98.0
18.6
97.5
-40
-25
-10
5
20
35
50
65
80
95
110
-40
125
-25
-10
5
20
fOSC vs. Temperature
Figure 15.
0.64
1.17
0.63
1.16
0.62
1.15
V IN-ON (V)
V IN-OFF (V)
Figure 14.
0.61
0.60
50
65
80
95
110
125
110
125
110
125
110
125
fOSC-G vs. Temperature
1.14
1.13
1.12
0.59
1.11
0.58
-40
-25
-10
5
20
35
50
65
80
95
110
-40
125
-25
-10
5
20
Figure 16.
35
50
65
80
95
Temperature(°C)
Temperature(°C)
VIN-OFF vs. Temperature
Figure 17.
4.63
0.34
4.62
0.33
4.61
0.32
V IN-L(V)
V IN-H (V)
35
Temperature(°C)
Temperature(°C)
4.60
0.31
4.59
0.30
4.58
0.29
4.57
VIN-ON vs. Temperature
0.28
-40
-25
-10
5
20
35
50
65
80
95
110
125
-40
-25
-10
5
20
Temperature(°C)
VIN-H vs. Temperature
Figure 18.
35
50
65
80
95
Temperature(°C)
Figure 19.
VIN-L vs. Temperature
2.60
4.75
4.70
2.55
2.50
4.60
V FB-N (V)
V FB-OLP(V)
4.65
4.55
4.50
2.45
2.40
4.45
2.35
4.40
4.35
2.30
-40
-25
-10
5
20
35
50
65
80
95
110
125
-40
-25
-10
Temperature(°C)
Figure 20.
20
35
50
65
80
95
Temperature(°C)
VFB-OLP vs. Temperature
© 2010 Fairchild Semiconductor Corporation
FSBH0F70A_F116, FSBH0170/0270/0370_F116 • Rev. 1.0.1
5
Figure 21.
VFB-N vs. Temperature
www.fairchildsemi.com
10
FSBH0F70A_F116, FSBH0170/0270/0370_F116 — Green Mode Fairchild Power Switch (FPS™)
Typical Characteristics
2.20
1.800
2.15
1.700
2.05
V FB-ZD C (V)
V FB-G(V)
2.10
2.00
1.95
1.600
1.500
1.400
1.90
1.300
1.85
1.80
1.200
-40
-25
-10
5
20
35
50
65
80
95
110
125
-40
-25
-10
5
20
Temperature(°C)
VFB-G vs. Temperature
Figure 23.
2.56
55.0
2.54
54.5
2.52
54.0
t D -OLP(ms)
IDD-ZDC (mA)
Figure 22.
35
50
65
80
95
110
125
110
125
Temperature(°C)
2.50
2.48
53.5
53.0
2.46
52.5
2.44
52.0
2.42
VFB-ZDC vs. Temperature
51.5
-40
-25
-10
5
20
35
50
65
80
95
110
125
-40
-25
-10
Temperature(°C)
Figure 24.
20
35
50
65
80
95
Temperature(°C)
IDD-ZDC vs. Temperature
© 2010 Fairchild Semiconductor Corporation
FSBH0F70A_F116, FSBH0170/0270/0370_F116 • Rev. 1.0.1
5
Figure 25.
tD-OLP vs. Temperature
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11
FSBH0F70A_F116, FSBH0170/0270/0370_F116 — Green Mode Fairchild Power Switch (FPS™)
Typical Characteristics
Startup Operation
Brown-In/Out Function
The HV pin is connected to bulk voltage through an
external resistor, RHV, as shown in Figure 26. When AC
voltage is applied to the power system, an internal HV
startup circuit provides a high current (around 3.5mA) to
charge an external VDD capacitor until VDD voltage
exceeds the turn-on threshold voltage (VDD-ON). For
lower power consumption, the HV startup circuit shuts
down during normal operation. The external VDD
capacitor and auxiliary winding maintain the VDD voltage
and provide operating current to controller.
FSBH0x70 has a built-in internal brown-in/out protection
comparator monitoring voltage of VIN pin. Figure 28
shows a resistive divider with low-pass filtering for linevoltage detection on the VIN pin.
Figure 28.
Figure 26.
Once the VIN pin voltage is lower than 0.6V and lasts
for 500ms, the PWM gate is disabled to protect the
system from over current. FSBH0x70 starts up as VIN
increases above 1.1V. Because the divider resistors of
the VIN pin are connected behind the bridge, the ratio
calculations for brownout in PFC and non-PFC system
are different, as shown in Figure 29. The formulas are
provided in the following equations:
Startup Circuit
Slope Compensation
The FSBH-series is designed for flyback power
converters. The peak-current-mode control is used to
optimize system performance. Slope compensation is
added to reduce current loop gain and improve power
system stability. The FSBH-series has a built-in,
synchronized, positive slope for each switching cycle.
Brownout with PFC:
RC
2
 2VAC _ OUT   0.6
RA  RB  RC

Soft-Start
(1)
Brownout with non-PFC:
The FSBH-series has an internal soft-start circuit that
reduces the SenseFET switching current during power
system startup. The characteristic curve of soft-start
time versus VLMT level is shown in Figure 27. The VLMT
level rises in six steps. By doing so, the power system
can smoothly build up the rated output voltage and
effectively reduce voltage stress on the PWM switch
and output diode.
Figure 27.
Brown-In/Out Function on VIN Pin
RC
 2VAC _ OUT  0.6
RA  RB  RC
(2)
Brown-in level is determined by:
VAC _ IN 
1.1 R A  RB  RC

RC
2
(3)
Soft-Start Function
Figure 29.
© 2010 Fairchild Semiconductor Corporation
FSBH0F70A_F116, FSBH0170/0270/0370_F116 • Rev. 1.0.1
VIN Level According to PFC Operation
www.fairchildsemi.com
12
FSBH0F70A_F116, FSBH0170/0270/0370_F116 — Green Mode Fairchild Power Switch (FPS™)
Functional Description
H/L Line Over-Power Compensation
The VIN pin functions are disabled in FSBH0F70A, but
FSBH0F70A has brown-in protection in the VDD pin.
There is a discharge current internal from VDD to ground
during startup. The HV source current must be larger
than IDD-ST to charge the capacitor of VDD. Therefore, the
brown-in level can be determined by RHV according to
the equation:
To limit the output power of the converter constantly,
high/low line over-power compensation is included.
Sensing the converter input voltage through the VIN pin,
the high/low line compensation function generates a
relative peak-current-limit threshold voltage for constant
power control, as shown in Figure 32.
RHV 
2VAC  12
IDD ST
(4)
Green-Mode Operation
The FSBH-series uses feedback voltage (VFB) as an
indicator of the output load and modulates the PWM
frequency, as shown in Figure 30, such that the
switching frequency decreases as load decreases. In
heavy-load conditions, the switching frequency is
100kHz. Once VFB decreases below VFB-N (2.5V), the
PWM frequency starts to linearly decrease from 100kHz
to 18kHz to reduce switching losses. As VFB decreases
below VFB-G (2.0V), the switching frequency is fixed at
18kHz and the FSBH-series enters “deep” green mode to
reduce the standby power consumption.
Figure 32.
Constant Power Control
Protections
The FSBH-series provides full protection functions to
prevent the power supply and the load from being
damaged. The protection features include:
Latch/Auto-Recovery Function
Besides the brownout protection and high/low line overpower compensation, the FSBH0X70_F116 has
additional protections via the VIN pin, such as pull-HIGH
latch and pull-LOW auto-recovery that depends on the
application. As shown in Figure 33, when VIN level is
higher than 4.7V, FSBH-series is latched until the VDD is
discharged. FSBH-series is auto-recovery when the VIN
level is lower than 0.3V.
Figure 30.
PWM Frequency
As VFB decreases below VFB-ZDC (1.6V), the FSBHseries enters burst-mode operation. When VFB drops
below VFB-ZDC, FSBH-series stops switching and the
output voltage starts to drop, which causes the feedback
voltage to rise. Once VFB rises above VFB-ZDC, switching
resumes. Burst mode alternately enables and disables
switching, thereby reducing switching loss to improve
power saving, as shown in Figure 31.
Figure 33.
VIN Pin Function
Open-Loop / Overload Protection (OLP)
When the upper branch of the voltage divider for the
shunt regulator (KA431 shown) is broken, as shown in
Figure 34, or over current or output short occurs, there
is no current flowing through the opto-coupler transistor,
which pulls the feedback voltage up to 6V.
When feedback voltage is above 4.6V for longer than
56ms, OLP is triggered. This protection is also triggered
when the SMPS output drops below the nominal value
longer than 56ms due to the overload condition.
Figure 31.
Burst-Mode Operation
© 2010 Fairchild Semiconductor Corporation
FSBH0F70A_F116, FSBH0170/0270/0370_F116 • Rev. 1.0.1
www.fairchildsemi.com
13
FSBH0F70A_F116, FSBH0170/0270/0370_F116 — Green Mode Fairchild Power Switch (FPS™)
Brown-In Function of FSBH0F70A
Over-Temperature Protection (OTP)
The SenseFET and the control IC are integrated,
making it easier to detect the temperature of the
SenseFET. As the temperature exceeds approximately
142°C, thermal shutdown is activated.
Figure 34.
OLP Operation
© 2010 Fairchild Semiconductor Corporation
FSBH0F70A_F116, FSBH0170/0270/0370_F116 • Rev. 1.0.1
www.fairchildsemi.com
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FSBH0F70A_F116, FSBH0170/0270/0370_F116 — Green Mode Fairchild Power Switch (FPS™)
VDD Over-Voltage Protection (OVP)
VDD over-voltage protection prevents IC damage caused
by over voltage on the VDD pin. The OVP is triggered
when VDD voltage reaches 28V. Debounce time (typically
130µs) prevents false trigger by switching noise.
FSBH0F70A_F116, FSBH0170/0270/0370_F116 — Green Mode Fairchild Power Switch (FPS™)
Physical Dimensions
Figure 35.
8-Pin Dual In-Line Package (DIP)
Package drawings are provided as a service to customers considering Fairchild components. Drawings may change in any manner
without notice. Please note the revision and/or date on the drawing and contact a Fairchild Semiconductor representative to verify or
obtain the most recent revision. Package specifications do not expand the terms of Fairchild’s worldwide terms and conditions, specifically the
warranty therein, which covers Fairchild products.
Always visit Fairchild Semiconductor’s online packaging area for the most recent package drawings:
http://www.fairchildsemi.com/packaging/.
© 2010 Fairchild Semiconductor Corporation
FSBH0F70A_F116, FSBH0170/0270/0370_F116 • Rev. 1.0.1
www.fairchildsemi.com
15
FSBH0F70A_F116, FSBH0170/0270/0370_F116 — Green Mode Fairchild Power Switch (FPS™)
© 2010 Fairchild Semiconductor Corporation
FSBH0F70A_F116, FSBH0170/0270/0370_F116 • Rev. 1.0.1
www.fairchildsemi.com
16