FAIRCHILD FSBH0270W

FSBH0F70WA, FSBH0170W, FSBH0270W
Green Mode Fairchild Power Switch (FPS™)
Features
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Brownout Protection with Hysteresis
Built-In 5ms Soft-Start Function
Internal Avalanche-Rugged 700V SenseFET
Low Acoustic Noise During Light-Load Operation
High-Voltage Startup
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)
Constant Power Limit (Full AC Input Range)
Internal OTP Sensor with Hysteresis
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
© 2011 Fairchild Semiconductor Corporation
FSBH0F70WA/0170W/0270W • Rev. 1.0.2
Description
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.
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.
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.
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.
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
FSBH0F70WA/0170W/0270W — Green Mode Fairchild Power Switch (FPS™)
June 2012
Part Number
SenseFET
VIN Pin
(PIN #4)
FSBH0F70WANY
0.5A 700V
Not
Available
FSBH0170WNY
1.0A 700V
FSBH0270WNY
2.0A 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
Table 1. Output Power Table(1)
Product
230VAC ± 15%(2)
85-265VAC
Adapter(3)
Open Frame(4)
Adapter(3)
Open Frame(4)
FSBH0F70WA
7W
10W
6W
8W
FSBH0170W
10W
15W
9W
13W
FSBH0270W
14W
20W
11W
16W
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.
© 2011 Fairchild Semiconductor Corporation
FSBH0F70WA/0170W/0270W • Rev. 1.0.2
www.fairchildsemi.com
2
FSBH0F70WA/0170W/0270W — Green Mode Fairchild Power Switch (FPS™)
Ordering Information
HV
Drain
5
6,7,8
HV
Startup
Debounce
Auto-ReStart
Protection
OVP
OVP
OLP
OTP
OSC
VPWM
S
VDD
Internal
BIAS
2
PWM
Soft
Driver
VDD-OVP
…
Q
R
VRESET
UVLO
Pattern
Generator
12V/8V
Soft-Start
Comparator
Soft-Start
VRESET
Current-Limit
Comparator
Green
Mode
VLimit
1
GND
3
FB
1
GND
3
FB
PWM
Comparator
VIN
6V
Max.
Duty
4
Slope
Compensation
VPWM
ZFB
3R
1.13V/0.59V
R
High/Low Line
Compensation
VLimit
OLP
Delay
OLP
Figure 2.
OLP
Comparator
FSBH0170W/0270W Internal Block Diagram
HV
Drain
5
6,7,8
HV
Startup
Debounce
Auto-ReStart
Protection
OVP
OVP
OLP
OTP
OSC
VPWM
S
Internal
BIAS
2
…
Q
R
VRESET
UVLO
Pattern
Generator
12V/8V
PWM
Soft
Driver
VDD-OVP
VDD
4.6V
Soft-Start
Comparator
Soft-Start
VRESET
Current-Limit
Comparator
Green
Mode
VLimit
PWM
Comparator
NC
Max.
Duty
4
6V
Slope
Compensation
VPWM
3R
ZFB
R
OLP
Figure 3.
© 2011 Fairchild Semiconductor Corporation
FSBH0F70WA/0170W/0270W • Rev. 1.0.2
OLP
Delay
OLP
Comparator
4.6V
FSBH0F70WA Internal Block Diagram
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3
FSBH0F70WA/0170W/0270W — Green Mode Fairchild Power Switch (FPS™)
Block Diagram
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.
NC
No Connection for FSBH0F70WA
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.
4
Description
© 2011 Fairchild Semiconductor Corporation
FSBH0F70WA/0170W/0270W • Rev. 1.0.2
www.fairchildsemi.com
4
FSBH0F70WA/0170W/0270W — 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
Parameter
Min.
Max.
Unit
700
V
FSBH0F70WA
VDRAIN
Drain Pin Voltage(5,6)
FSBH0170W
FSBH0270W
IDM
EAS
Drain Current Pulsed(7)
(8)
Single Pulsed Avalanche Energy
FSBH0F70WA
1.5
FSBH0170W
4.0
FSBH0270W
8.0
FSBH0F70WA
10
A
FSBH0170W
50
FSBH0270W
140
mJ
VDD
DC Supply Voltage
VFB
FB Pin Input Voltage
-0.3
7.0
V
VIN
VIN Pin Input Voltage
-0.3
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
30
Junction-to-Top Thermal Resistance
(9)
V
°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 Pn): JESD22-A114
ESD
Charged Device Model
(All Pins Except HV Pin): JESD22-C101
FSBH0F70WA
5.0
FSBH0170W
5.0
FSBH0270W
5.0
FSBH0F70WA
2.0
FSBH0170W
2.0
FSBH0270W
2.0
(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
© 2011 Fairchild Semiconductor Corporation
FSBH0F70WA/0170W/0270W • Rev. 1.0.2
Min.
Max.
Unit
-40
+105
°C
www.fairchildsemi.com
5
FSBH0F70WA/0170W/0270W — 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)
Drain-Source OnState Resistance(12)
VGS=10V, ID=0.5A
Input Capacitance
VGS=0V, VDS=25V,
f=1MHz
CISS
COSS
CRSS
tD(ON)
tR
tD(OFF)
tF
Output Capacitance
VDS=700V, VGS=0V
50
VDS=560V, VGS=0V, TC=125°C
200
VGS=0V, VDS=25V,
f=1MHz
VGS=0V, VDS=25V,
f=1MHz
Turn-On Delay
VDS=350V, ID=1.0A
Turn-Off Delay
Fall Time
V
VDS=700V, VGS=0V
Reverse Transfer
Capacitance
Rise Time
700
VDS=350V, ID=1.0A
VDS=350V, ID=1.0A
VDS=350V, ID=1.0A
FSBH0F70WA
14.00
19.00
FSBH0170W
8.80
11.00
FSBH0270W
6.00
7.20
FSBH0F70WA
162
211
FSBH0170W
250
325
FSBH0270W
550
715
FSBH0F70WA
18
24
FSBH0170W
25
33
FSBH0270W
38
50
FSBH0F70WA
3.8
5.7
FSBH0170W
10
15
FSBH0270W
17
26
FSBH0F70WA
9.5
29.0
FSBH0170W
12.0
34.0
FSBH0270W
20.0
50.0
FSBH0F70WA
19
48
FSBH0170W
4
18
FSBH0270W
15
40
FSBH0F70WA
33.0
76.0
FSBH0170W
30.0
70.0
FSBH0270W
55.0
120.0
FSBH0F70WA
42
94
FSBH0170W
10
30
FSBH0270W
25
60
μA
Ω
pF
pF
pF
ns
ns
ns
ns
Continued on the following page…
© 2011 Fairchild Semiconductor Corporation
FSBH0F70WA/0170W/0270W • Rev. 1.0.2
www.fairchildsemi.com
6
FSBH0F70WA/0170W/0270W — 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
FSBH0170W
FSBH0270W
VDD-ON – 0.16V
30
IDD-ST
Startup Current
VDD-ON – 0.16V
240
320
400
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
VTH-OLP+0.1V
FSBH0F70WA
µA
IDD-OLP
Internal Sink Current
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
(11)
Deviation
TA=-25 to 85°C
5
%
VIN Section (FSBH0170W & FSBH0270W)
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
500
ms
Feedback Input Section
AV
FB Voltage to Current-Sense Attenuation
ZFB
Input Impedance
VFB-OPEN
Output High Voltage
1/4.5
4
FB Pin Open
5.5
1/4.0
1/3.5
V/V
7
kΩ
V
Continued on the following page…
© 2011 Fairchild Semiconductor Corporation
FSBH0F70WA/0170W/0270W • Rev. 1.0.2
www.fairchildsemi.com
7
FSBH0F70WA/0170W/0270W — 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
FSBH0F70WA
5.2
5.4
5.6
FSBH0x7W
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
FSBH0F70WA
VIN Open
0.63
0.73
0.83
FSBH0170W
VIN=1.2V
0.70
0.80
0.90
FSBH0270W
VIN=1.2V
0.90
1.00
1.10
4.5
5.0
5.5
ms
(11)
Period During Soft-Start Time
A
Constant Power Limit (FSBH0170W & FSBH0270W)
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
+142
+150
Constant Power Limit (FSBH0F70WA)
VLMT
Threshold Voltage for Current Limit
Over-Temperature Protection Section (OTP)
TOTP
TRESTART
Protection Junction Temperature(11,13)
+135
Restart Junction Temperature(11,14)
TOTP-25
°C
°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.
© 2011 Fairchild Semiconductor Corporation
FSBH0F70WA/0170W/0270W • Rev. 1.0.2
VFB vs. PWM Frequency
www.fairchildsemi.com
8
FSBH0F70WA/0170W/0270W — Green Mode Fairchild Power Switch (FPS™)
Electrical Characteristics (Continued)
14
3.02
12
3.00
2.98
2.96
ID D -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 D D -OF F (V)
V D D -ON (V)
Figure 6.
11.8
11.6
11.4
65
80
95
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
110
125
Temperature(°C)
VDD-ON vs. Temperature
Figure 9.
6.6
28.42
6.4
28.41
6.2
VDD-OFF vs. Temperature
28.40
6.0
V D D -OVP (V)
V T H -OLP(V)
50
7.8
11.2
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
20
Temperature(°C)
Figure 10.
35
50
65
80
95
110
125
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
5
Temperature(°C)
Figure 12.
35
50
65
80
95
110
125
Temperature(°C)
IHV vs. Temperature
© 2011 Fairchild Semiconductor Corporation
FSBH0F70WA/0170W/0270W • Rev. 1.0.2
20
Figure 13.
IHV-LC vs. Temperature
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9
FSBH0F70WA/0170W/0270W — Green Mode Fairchild Power Switch (FPS™)
Typical Characteristics (Continued)
101.5
19.2
101.0
19.1
F OSC -G (kHz)
F OSC (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 -OF F (V)
Figure 14.
0.61
0.60
50
65
80
95
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
110
125
Temperature(°C)
Temperature(°C)
VIN-OFF vs. Temperature
Figure 17.
2.56
2.60
2.54
2.55
2.52
VIN-ON vs. Temperature
2.50
V F B-N (V)
ID D -Z D C (mA)
35
Temperature(°C)
Temperature(°C)
2.50
2.48
2.46
2.45
2.40
2.35
2.44
2.30
2.42
-40
-25
-10
5
20
35
50
65
80
95
110
-40
125
-25
-10
5
Figure 18.
20
35
50
65
80
95
110
125
110
125
Temperature(°C)
Temperature(°C)
IDD-ZDC vs. Temperature
Figure 19.
VFB-N vs. Temperature
1.800
2.20
2.15
1.700
2.05
V F B-Z D C (V)
V F B-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
-40
125
-25
-10
Figure 20.
VFB-G vs. Temperature
© 2011 Fairchild Semiconductor Corporation
FSBH0F70WA/0170W/0270W • Rev. 1.0.2
5
20
35
50
65
80
95
Temperature(°C)
Temperature(°C)
Figure 21.
VFB-ZDC vs. Temperature
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10
FSBH0F70WA/0170W/0270W — Green Mode Fairchild Power Switch (FPS™)
Typical Characteristics (Continued)
Startup Operation
The HV pin is connected to bulk voltage through an
external resistor, RHV, as shown in Figure 22. 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.
Figure 24.
Figure 22.
Brown-In/Out Function on VIN Pin
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. FSBH0170W/0270W 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 1.
The formulas are provided in the following equations:
Brownout with PFC:
Startup Circuit
RC
2
⋅ 2VAC _ OUT ⋅ = 0.6
+
+
π
RA RB RC
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.
(1)
Brownout with non-PFC:
RC
⋅ 2VAC _ OUT = 0.6
RA + RB + RC
(2)
Brown-in level is determined by:
Soft-Start
VAC _ IN =
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 1. 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 25.
1.1 R A + RB + RC
⋅
RC
2
(3)
VIN Level According to PFC Operation
Brown-In Function of FSBH0F70WA
Figure 23.
The VIN pin functions are disabled from FSBH0F70WA
which still exist brown-in protection in VDD pin. There is
a discharge current internal from VDD to ground during
startup. The HV source current must be larger than IDDST to charge the capacitor of VDD. The brown-in level can
be determined by RHV according to the equation:
Soft-Start Function
Brown-In/Out Function
FSBH0170W/0270W has a built-in internal brown-in/out
protection comparator monitoring voltage of the VIN pin.
Figure 24 shows a resistive divider with low-pass
filtering for line-voltage detection on the VIN pin.
© 2011 Fairchild Semiconductor Corporation
FSBH0F70WA/0170W/0270W • Rev. 1.0.2
RHV =
2VAC − 12
IDD −ST
(4)
www.fairchildsemi.com
11
FSBH0F70WA/0170W/0270W — Green Mode Fairchild Power Switch (FPS™)
Functional Description
The FSBH-series uses feedback voltage (VFB) as an
indicator of the output load and modulates the PWM
frequency, as shown in Figure 26, 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 28.
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:
Figure 26.
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 29, 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.
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 1.
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.
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.
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 27.
Burst-Mode Operation
H/L Line Over-Power Compensation
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 28.
Figure 29.
© 2011 Fairchild Semiconductor Corporation
FSBH0F70WA/0170W/0270W • Rev. 1.0.2
OLP Operation
www.fairchildsemi.com
12
FSBH0F70WA/0170W/0270W — Green Mode Fairchild Power Switch (FPS™)
Green-Mode Operation
[
]
0.400 10.160
0.355 9.017
8
5
PIN 1 INDICATOR
1
]
0.015 [0.389] GAGE PLANE
[
0.280 7.112
0.240 6.096
4
HALF LEAD 4X
0.005 [0.126]
FULL LEAD 4X
0.005 [0.126] MIN
[
0.195 4.965
0.115 2.933
MAX 0.210 [5.334]
]
[
0.325 8.263
0.300 7.628
]
SEATING PLANE
[
]
0.150 3.811
0.115 2.922
C
MIN 0.015 [0.381]
0.100 [2.540]
[
0.022 0.562
0.014 0.358
0.300 [7.618]
[
] 4X
0.045 1.144
0.030 0.763
]
[
0.070 1.778
0.045 1.143
0.10
C
] 4X
0.430 [10.922]
MAX
NOTES:
A) THIS PACKAGE CONFORMS TO
JEDEC MS-001 VARIATION BA
B) CONTROLING DIMS ARE IN INCHES
C) DIMENSIONS ARE EXCLUSIVE OF BURRS,
MOLD FLASH, AND TIE BAR EXTRUSIONS.
D) DIMENSIONS AND TOLERANCES PER ASME
Y14.5M -1982
E) DRAWING FILENAME AND REVSION: MKT-N08MREV1.
Figure 30.
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/.
© 2011 Fairchild Semiconductor Corporation
FSBH0F70WA/0170W/0270W • Rev. 1.0.2
www.fairchildsemi.com
13
FSBH0F70WA/0170W/0270W — Green Mode Fairchild Power Switch (FPS™)
Physical Dimensions
FSBH0F70WA/0170W/0270W — Green Mode Fairchild Power Switch (FPS™)
© 2011 Fairchild Semiconductor Corporation
FSBH0F70WA/0170W/0270W • Rev. 1.0.2
www.fairchildsemi.com
14