FAIRCHILD FSDH0170RNB

FSDH0170RNB/FSDH0270RNB/FSDH0370RNB
Green Mode Fairchild Power Switch (FPS™)
Features
Description
„ Internal Avalanche Rugged 700V Sense FET
The FSDH0170RNB/FSDH0270RNB/FSDH0370RNB
consists of an integrated current mode Pulse Width Modulator (PWM) and an avalanche rugged 700V Sense
FET. It is specifically designed for high performance offline Switch Mode Power Supplies (SMPS) with minimal
external components. The integrated PWM controller
features include : a fixed oscillator with frequency modulation for reduced EMI, Under Voltage Lock Out (UVLO)
protection, Leading Edge Blanking (LEB), an optimized
gate turn-on/ turn-off driver, Thermal Shut Down (TSD)
protection, and temperature compensated precision current sources for loop compensation and fault protection
circuitry. Compared to a discrete MOSFET and controller
or RCC switching converter solution, the FSDH0170RNB/
FSDH0270RNB/FSDH0370RNB reduces total 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, as in PC
auxiliary power supplies.
„ Consumes only 0.8W at 230 VAC & 0.5W load with
Burst-Mode Operation
„ Frequency Modulation for EMI Reduction
„ Precision Fixed Operating Frequency, 100kHz
„ Internal Start-up Circuit and Built-in Soft Start
„ Pulse-by-Pulse Current Limiting and Auto-Restart
Mode
„ Over Voltage Protection (OVP), Over Load Protection
(OLP), Internal Thermal Shutdown Function (TSD)
„ Under Voltage Lockout (UVLO)
„ Low Operating Current (3mA)
„ Adjustable Peak Current Limit
Applications
„ Auxiliary Power Supply for PC and Server
„ SMPS for VCR, SVR, STB, DVD & DVCD Player
„ SMPS for Printer, Facsimile & Scanner
„ Adapter for Camcorder
Related Application Notes
„ AN-4137, AN-4141, AN-4147 (Flyback)
„ AN-4134 (Forward)
Ordering Information
Product Number
Package
Marking Code
BVDSS
fOSC
RDS(ON) (MAX.)
FSDH0170RNB
8DIP
DH0170R
700V
100KHz
11Ω
FSDH0270RNB
8DIP
DH0270R
700V
100KHz
7.2Ω
FSDH0370RNB
8DIP
DH0370R
700V
100KHz
4.75Ω
©2006 Fairchild Semiconductor Corporation
FSDH0170RNB/FSDH0270RNB/FSDH0370RNB Rev. 1.0.2
1
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FSDH0170RNB/FSDH0270RNB/FSDH0370RNB Green Mode Fairchild Power Switch (FPS™)
March 2006
AC
IN
DC
OUT
Vstr
Ipk
Drain
PWM
Vfb
Vcc
Source
Figure 1. Typical Flyback Application
Output Power Table(4)
230VAC ±15%(3)
85–265VAC
Product
Adapter(1)
FSDH0170RNB
14W
20W
9W
13W
FSDH0270RNB
17W
24W
11W
16W
FSDH0370RNB
20W
27W
13W
19W
Open
Frame(2)
Adapter(1)
Open Frame(2)
Notes:
1. Typical continuous power in a non-ventilated enclosed adapter with sufficient drain pattern as a heat sinker, at 50°C ambient.
2. Maximum practical continuous power in an open frame design with sufficient drain pattern as a heat sinker, at 50°C ambient.
3. 230 VAC or 100/115 VAC with doubler.
4. The maximum output power can be limited by junction temperature.
Internal Block Diagram
D rain
6,7,8
Vstr
5
Vcc
2
IC H
8V/12V
Vcc good
Vcc
Internal
Bias
Vref
Freq.
M odulation
V BU R L /V BU RH
Vcc
OSC
I DELA Y
Vfb
I FB
N orm al
3
2.5R
Ipk
PW M
Burst
S
Q
R
Q
G ate
driver
R
4
LEB
V SD
1 GND
Vcc
S
Q
R
Q
Vovp
Vcc good
TSD
Soft Start
Figure 2. Functional Block Diagram of FSDH0170RNB/FSDH0270RNB/FSDH0370RNB
FSDH0170RNB/FSDH0270RNB/FSDH0370RNB Rev. 1.0.2
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FSDH0170RNB/FSDH0270RNB/FSDH0370RNB Green Mode Fairchild Power Switch (FPS™)
Typical Circuit
8DIP
GND 1
8 Drain
Vcc 2
7 Drain
Vfb 3
6 Drain
Ipk 4
5 Vstr
Figure 3. Pin Configuration (Top View)
Pin Definitions
Pin Number
Pin Name
Pin Function Description
1
GND
Sense FET source terminal on primary side and internal control ground.
2
Vcc
Positive supply voltage input. Although connected to an auxiliary transformer
winding, current is supplied from pin 5 (Vstr) via an internal switch during
startup (see Internal Block Diagram Section). It is not until Vcc reaches the
UVLO upper threshold (12V) that the internal start-up switch opens and device
power is supplied via the auxiliary transformer winding.
3
Vfb
The feedback voltage pin is the non-inverting input to the PWM comparator.
It has a 0.9mA current source connected internally while a capacitor and
optocoupler are typically connected externally. A feedback voltage of 6V
triggers overload protection (OLP). There is a time delay while charging
external capacitor Cfb from 3V to 6V using an internal 5µA current source.
This time delay prevents false triggering under transient conditions but still
allows the protection mechanism to operate under true overload conditions.
4
Ipk
This pin adjusts the peak current limit of the Sense FET. The 0.9mA feedback
current source is diverted to the parallel combination of an internal 2.8kΩ
resistor and any external resistor to GND on this pin. This determines the
peak current limit. If this pin is tied to Vcc or left floating, the typical peak
current limit will be 0.8A (FSDH0170RNB), 0.9A (FSDH0270RNB), or
1.1A (FSDH0370RNB).
5
Vstr
This pin connects to the rectified AC line voltage source. At start-up the
internal switch supplies internal bias and charges an external storage
capacitor placed between the Vcc pin and ground. Once the Vcc reaches
12V, the internal switch is opened.
6, 7, 8
Drain
The drain pins are designed to connect directly to the primary lead of the
transformer and are capable of switching a maximum of 700V. Minimizing the
length of the trace connecting these pins to the transformer will decrease
leakage inductance.
FSDH0170RNB/FSDH0270RNB/FSDH0370RNB Rev. 1.0.2
3
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FSDH0170RNB/FSDH0270RNB/FSDH0370RNB Green Mode Fairchild Power Switch (FPS™)
Pin Configuration
(TA = 25°C, unless otherwise specified)
Symbol
VDRAIN
VSTR
IDM
EAS
Parameter
Value
Unit
Drain Pin Voltage
700
V
Vstr Pin Voltage
700
V
FSDH0170RNB
4
A
FSDH0270RNB
8
A
5
Drain Current Pulsed
Single Pulsed Avalanche Energy6
VCC
Supply Voltage
VFB
Feedback Voltage Range
PD
Total Power Dissipation
TJ
Operating Junction Temperature
TA
TSTG
FSDH0370RNB
12
A
FSDH0170RNB
50
mJ
FSDH0270RNB
140
mJ
FSDH0370RNB
230
mJ
20
V
-0.3 to VCC
V
1.5
W
Internally limited
°C
Operating Ambient Temperature
-25 to +85
°C
Storage Temperature
-55 to +150
°C
Thermal Impedance
(TA = 25°C, unless otherwise specified)
Symbol
Parameter
Value
Unit
80
°C/W
20
°C/W
35
°C/W
8 DIP
θJA
θJC
ψJT
Junction-to-Ambient Thermal7
Junction-to-Case
Junction-to-Top
Thermal8
Thermal9
All items are tested with the standards JESD 51-2 and 51-10 (DIP).
Notes:
5. Non-repetitive rating: Pulse width is limited by maximum junction temperature.
6. L = 51mH, starting Tj = 25°C.
7. Free standing with no heatsink; Without copper clad.
8. Measured on the DRAIN pin close to plastic interface.
9. Measured on the PKG top surface.
FSDH0170RNB/FSDH0270RNB/FSDH0370RNB Rev. 1.0.2
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FSDH0170RNB/FSDH0270RNB/FSDH0370RNB Green Mode Fairchild Power Switch (FPS™)
Absolute Maximum Ratings
(TA = 25°C unless otherwise specified)
Symbol
Parameter
Sense FET Section
IDSS
RDS(ON)
CISS
Zero-Gate-Voltage Drain Current
Drain-Source
On-State
Resistance10
FSDH0170RNB
CRSS
td(on)
tr
td(off)
tf
Min.
Typ.
Max.
Unit
VDS = 700V, VGS = 0V
–
–
50
μA
VDS = 560V, VGS = 0V,
TC = 125°C
–
–
200
VGS = 10V, ID = 0.5A
–
8.8
11
FSDH0270RNB
–
6.0
7.2
FSDH0370RNB
–
4.0
4.75
Input Capacitance
FSDH0170RNB
–
250
–
FSDH0270RNB
COSS
Condition
11
Output Capacitance
Reverse Transfer
Capacitance
Turn-On Delay Time
Rise Time
Turn-Off Delay Time
Fall Time
VGS = 0V, VDS = 25V,
f = 1MHz
–
550
–
FSDH0370RNB
–
315
–
FSDH0170RNB
–
25
–
FSDH0270RNB
–
38
–
FSDH0370RNB
–
47
–
FSDH0170RNB
–
10
–
FSDH0270RNB
–
17
–
FSDH0370RNB
–
9
–
–
12
–
FSDH0270RNB
FSDH0170RNB
VDS = 350V, ID = 1.0A
–
20
–
FSDH0370RNB
–
11.2
–
FSDH0170RNB
–
4
–
FSDH0270RNB
–
15
–
FSDH0370RNB
–
34
–
FSDH0170RNB
–
30
–
FSDH0270RNB
–
55
–
FSDH0370RNB
–
28.2
–
FSDH0170RNB
–
10
–
FSDH0270RNB
–
25
–
FSDH0370RNB
–
32
–
Ω
pF
ns
Control Section
Switching Frequency
92
100
108
KHz
ΔfMOD
fOSC
Switching Frequency Modulation
±2
±3
±4
KHz
ΔfOSC
Switching Frequency Variation11
-25°C ≤ TA ≤ 85°C
–
±5
±10
%
DMAX
Maximum Duty Cycle
Measured @0.1 x Vds
62
67
72
%
DMIN
Minimum Duty Cycle
0
0
0
%
VFB = GND
11
12
13
V
VFB = GND
7
8
9
VFB = GND
0.7
0.9
1.1
mA
–
10
–
ms
VSTART
UVLO Threshold Voltage
VSTOP
IFB
Feedback Source Current
tS/S
Time11
Internal Soft Start
FSDH0170RNB/FSDH0270RNB/FSDH0370RNB Rev. 1.0.2
VFB = 4V
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FSDH0170RNB/FSDH0270RNB/FSDH0370RNB Green Mode Fairchild Power Switch (FPS™)
Electrical Characteristics
(TA = 25°C unless otherwise specified)
Symbol
Parameter
Condition
Min.
Typ.
Max.
Unit
0.5
0.6
0.7
V
VBURL
0.3
0.4
0.5
V
VBUR(HYS)
100
200
300
mV
A
Burst Mode Section
VBURH
Tj = 25°C
Burst Mode Voltage
Protection Section
ILIM
tCLD
Peak Current Limit
FSDH0170RNB
di/dt = 170mA/µs
0.70
0.80
0.90
FSDH0270RNB
di/dt = 200mA/µs
0.79
0.90
1.01
FSDH0370RNB
di/dt = 240mA/µs
0.97
1.10
1.23
–
500
–
ns
Current Limit Delay
Time11
Temperature11
TSD
Thermal Shutdown
125
140
–
°C
VSD
Shutdown Feedback Voltage
5.5
6.0
6.5
V
VOVP
Over Voltage Protection
18
19
–
V
IDELAY
Shutdown Delay Current
3.5
5.0
6.5
μA
200
–
–
ns
tLEB
Leading Edge Blanking
VFB = 4V
Time11
Total Device Section
IOP
Operating Supply Current
(control part only)
VCC = 14V
1
3
5
mA
ICH
Start-Up Charging Current
VCC = 0V
0.7
0.85
1.0
mA
Vstr Supply Voltage
VCC = 0V
–
24
–
V
VSTR
Notes:
10. Pulse test : Pulse width ≤ 300µs, duty ≤ 2%
11. These parameters, although guaranteed, are not 100% tested in production.
FSDH0170RNB/FSDH0270RNB/FSDH0370RNB Rev. 1.0.2
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FSDH0170RNB/FSDH0270RNB/FSDH0370RNB Green Mode Fairchild Power Switch (FPS™)
Electrical Characteristics (Continued)
1.20
1.20
1.00
1.00
Normalized
Normalized
(These characteristic graphs are normalized at TA = 25°C)
0.80
0.60
0.40
0.20
0.80
0.60
0.40
0.20
0.00
0.00
-50
0
50
100
150
-50
0
Temp[°C]
100
150
Frequency Modulation (ΔfMOD) vs. TA
1.20
1.20
1.00
1.00
Normalized
Normalized
Operating Frequency (fosc) vs. TA
0.80
0.60
0.40
0.20
0.80
0.60
0.40
0.20
0.00
0.00
-50
0
50
100
150
-50
0
Temp[°C]
50
100
150
Temp[°C]
Maximum Duty Cycle (DMAX) vs. TA
Operating Supply Current (IOP) vs. TA
1.20
1.20
1.00
1.00
Normalized
Nomalized
50
Temp[°C]
0.80
0.60
0.40
0.20
0.80
0.60
0.40
0.20
0.00
0.00
-50
0
50
100
150
-50
Temp[°C]
50
100
150
Temp[°C]
Start Threshold Voltage (VSTART) vs. TA
FSDH0170RNB/FSDH0270RNB/FSDH0370RNB Rev. 1.0.2
0
Stop Threshold Voltage (VSTOP) vs. TA
7
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FSDH0170RNB/FSDH0270RNB/FSDH0370RNB Green Mode Fairchild Power Switch (FPS™)
Typical Performance Characteristics (Control Part)
1.20
1.00
1.00
Normalized
Normalized
1.20
0.80
0.60
0.40
0.80
0.60
0.40
0.20
0.20
0.00
0.00
-50
0
50
100
-50
150
0
Feedback Source Current (IFB) vs. TA
100
150
Start Up Charging Current (ICH) vs. TA
1.20
1.20
1.00
1.00
Normalized
Normalized
50
Temp[°C]
Temp[°C]
0.80
0.60
0.40
0.20
0.80
0.60
0.40
0.20
0.00
0.00
-50
0
50
100
150
-50
Temp[°C]
50
100
150
Temp[°C]
Peak Current Limit (ILIM) vs. TA
FSDH0170RNB/FSDH0270RNB/FSDH0370RNB Rev. 1.0.2
0
Over Voltage Protection (VOVP) vs. TA
8
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FSDH0170RNB/FSDH0270RNB/FSDH0370RNB Green Mode Fairchild Power Switch (FPS™)
Typical Performance Characteristics (Continued)
3. Leading Edge Blanking (LEB): When the internal
Sense FET is turned on; the primary side capacitance
and secondary side rectifier diode reverse recovery
typically cause a high current spike through the Sense
FET. Excessive voltage across the Rsense resistor
leads 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 Sense FET is turned on.
1. Startup: In previous generations of Fairchild Power
Switches (FPS™) the Vstr pin required an external
resistor to the DC input voltage line. In this generation
the startup resistor is replaced by an internal high
voltage current source and a switch that shuts off 10ms
after the supply voltage, Vcc, goes above 12V. The
source turns back on if Vcc drops below 8V.
4. Protection Circuits: The FPS has several protective
functions such as Over Load Protection (OLP), Over
Voltage Protection (OVP), Under Voltage Lock Out
(UVLO), and Thermal Shut Down (TSD). Because these
protection circuits are fully integrated inside the IC
without external components, reliability is improved
without increasing cost. Once a fault condition occurs,
switching is terminated and the Sense FET remains off.
This causes Vcc to fall. When Vcc reaches the UVLO
stop voltage, VSTOP (typically 8V), the protection is reset
and the internal high voltage current source charges the
Vcc capacitor via the Vstr pin. When Vcc reaches the
UVLO start voltage, VSTART (typically 12V), the FPS
resumes its normal operation. In this manner, the autorestart can alternately enable and disable the switching
of the power Sense FET until the fault condition is
eliminated.
Vin,dc
ISTR
Vstr
Vcc<8V
UVLO on
Vcc
J-FET
ICH
10ms after
Vcc≥ 12V
UVLO off
Figure 4. High Voltage Current Source
2. Feedback Control: The 700V FPS series employs
current mode control, as shown in Figure 5. An
optocoupler (such as the H11A817A) 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 of Sense FET plus an offset voltage makes it
possible to control the switching duty cycle. When the
KA431 reference pin voltage exceeds the internal
reference voltage of 2.5V, the optocoupler LED current
increases, the feedback voltage Vfb is pulled down and
thereby reduces the duty cycle. This typically happens
when the input voltage increases or the output load
decreases.
Vcc
Vcc
5uA
0.9mA
Vfb
3
Vo
CFB
4.1 Over Load Protection (OLP): Overload is defined
as the load current exceeding a pre-set level due to an
unexpected event. In this situation, the protection circuit
should be activated in order to protect the SMPS.
However, even when the SMPS is operating normally,
the Over Load Protection (OLP) circuit can be activated
during the load transition. In order to avoid this undesired
operation, the OLP circuit is designed to be activated
after a specified time to determine whether it is a
transient situation or an overload situation. In
conjunction with the Ipk current limit pin (if used) the
current mode feedback path would limit the current in the
Sense FET when the maximum PWM duty cycle is
attained. If the output consumes more than this
maximum power, the output voltage (Vo) decreases
below its nominal voltage. This reduces the current
through the optocoupler LED, which also reduces the
optocoupler transistor current, thus increasing the
feedback voltage (VFB). If VFB exceeds 3V, the feedback
input diode is blocked and the 5µA current source
(IDELAY) starts to slowly charge Cfb up to Vcc. In this
condition, VFB increases until it reaches 6V, when the
switching operation is terminated as shown in Figure 6.
The shutdown delay time is the time required to charge
Cfb from 3V to 6V with 5µA current source.
OSC
+
VFB
-
D1
D2
2.5R
VFB,in
Gate
driver
R
431
VSD
OLP
Figure 5. Pulse Width Modulation (PWM) Circuit
FSDH0170RNB/FSDH0270RNB/FSDH0370RNB Rev. 1.0.2
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FSDH0170RNB/FSDH0270RNB/FSDH0370RNB Green Mode Fairchild Power Switch (FPS™)
Functional Description
#6,7,8
5V
Over Load Protection
D R AIN
6V
#1
GND
3V
I LIM
R sense
t12= CFB×(V(t2)-V(t1)) / IDELAY
t1
t12 = C FB
V (t2 ) − V (t1 )
;
I DELAY
t2
t
Figure 7. Soft Start Function
I DELAY = 5 μA, V (t1 ) = 3V , V (t 2 ) = 6V
6. Burst Operation: In order to minimize power
dissipation in standby mode, the FPS enters burst mode
operation. Feedback voltage decreases as the load
decreases and as shown in Figure 8, the device
automatically enters burst mode when the feedback
voltage drops below VBURH (typically 600mV). Switching
still continues until the feedback voltage drops below
VBURL (typically 400mV). At this point switching stops
and the output voltage start to drop at a rate dependent
on the standby current load. This causes the feedback
voltage to rise. Once it passes VBURH, switching
resumes. The feedback voltage then falls and the
process is repeated. Burst mode operation alternately
enables and disables switching of the Sense FET and
reduces switching loss in standby mode.
Figure 6. Over Load Protection (OLP)
4.2 Thermal Shutdown (TSD): The Sense FET and the
control IC are integrated, making it easier for the control
IC to detect the temperature of the Sense FET. When
the temperature exceeds approximately 140°C, thermal
shutdown is activated.
4.3 Over Voltage Protection (OVP): In the event of a
malfunction in the secondary side feedback circuit, or an
open feedback loop caused by a soldering defect, the
current through the optocoupler transistor becomes
almost zero (refer to Figure 5). Then, 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 is activated. Because
excess energy is provided to the output, the output
voltage may exceed the rated voltage before the
overload protection is activated, resulting in the
breakdown of the devices in the secondary side. In order
to prevent this situation, an Over Voltage Protection
(OVP) circuit is employed. In general, VCC is proportional
to the output voltage and the FPS uses VCC instead of
directly monitoring the output voltage. If VCC exceeds
19V, OVP circuit is activated resulting in termination of
the switching operation. In order to avoid undesired
activation of OVP during normal operation, Vcc should
be designed to be below 19V.
Burst
Operation
Normal
Operation
VFB
VBURH
VBURL
Current
Waveform
Switching
OFF
Switching
OFF
Figure 8. Burst Operation Function
5. Soft Start: The FPS has an internal soft start circuit
that slowly increases the Sense FET current after startup
as shown in Figure 7. The typical soft start time is 10ms,
where progressive increments of the Sense FET current
are allowed during the start-up phase. 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 also helps to prevent transformer saturation and
reduce the stress on the secondary diode during startup.
FSDH0170RNB/FSDH0270RNB/FSDH0370RNB Rev. 1.0.2
Burst
Operation
7. Frequency Modulation: Modulating the switching
frequency of a switched power supply can reduce EMI.
Frequency modulation can reduce EMI by spreading the
energy over a wider frequency range than the bandwidth
measured by the EMI test equipment. The amount of
EMI reduction is directly related to the depth of the
reference frequency. As can be seen in Figure 9, the
frequency changes from 97KHz to 103KHz in 4ms for
the 700V FPS series. Frequency modulation allows the
use of a cost effective inductor instead of an AC input
mode choke to satisfy the requirements of world wide
EMI limits.
10
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FSDH0170RNB/FSDH0270RNB/FSDH0370RNB Green Mode Fairchild Power Switch (FPS™)
VFB
Vcc
Vcc
5uA
ts
IDELAY
Vfb
900uA
IFB
2kΩ
PWM
Comparator
3
fs=1/ts
103kHz
100kHz
97kHz
0.8k Ω
Ipk
4
4ms
Rx
t
SenseFET
Current
Sense
Figure 9. Frequency Modulation Waveform
Figure 10. Peak Current Limit Adjustment
8. Adjusting Peak Current Limit: As shown in Figure
10, a combined 2.8kΩ internal resistance is connected to
the non-inverting lead on the PWM comparator. An
external resistance of Rx on the current limit pin forms a
parallel resistance with the 2.8kΩ when the internal
diodes are biased by the main current source of 900µA.
For example, FSDH0270RNB has a typical Sense FET
peak current limit (ILIM) of 0.9A. ILIM can be adjusted to
0.6A by inserting Rx between the Ipk pin and the ground.
The value of the Rx can be estimated by the following
equations:
0.9A : 0.6A = 2.8kΩ : XkΩ,
X = Rx || 2.8kΩ.
(X represents the resistance of the parallel network)
FSDH0170RNB/FSDH0270RNB/FSDH0370RNB Rev. 1.0.2
11
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FSDH0170RNB/FSDH0270RNB/FSDH0370RNB Green Mode Fairchild Power Switch (FPS™)
Drain
Current
1. Methods of Reducing Audible Noise
Switching mode power converters have electronic and
magnetic components, which generate audible noises
when the operating frequency is in the range of
20~20,000Hz. Even though they operate above 20KHz,
they can make noise depending on the load condition.
Here are three methods to reduce noise:
Glue or Varnish
The most common method involves using glue or
varnish to tighten magnetic components. The motion of
core, bobbin, and coil and the chattering or
magnetostriction of core can cause the transformer to
produce audible noise. The use of rigid glue and varnish
helps reduce the transformer noise. Glue or varnish can
also can crack the core because sudden changes in the
ambient temperature cause the core and the glue to
expand or shrink in a different ratio according to the
temperature.
Figure 11. Equal Loudness Curves
Ceramic Capacitor
Using a film capacitor instead of a ceramic capacitor as a
snubber capacitor is another noise reduction solution.
Some dielectric materials show a piezoelectric effect
depending on the electric field intensity. Hence, a
snubber capacitor becomes one of the most significant
sources of audible noise. Another consideration is to
use a zener clamp circuit instead of an RCD snubber for
higher efficiency as well as lower audible noise.
Adjusting Sound Frequency
Moving the fundamental frequency of noise out of
2~4KHz range is the third method. Generally, humans
are more sensitive to noise in the range of 2~4KHz.
When the fundamental frequency of noise is located in
this range, the noise sounds louder although the noise
intensity level is identical. Refer to Figure 11.
Figure 12. Typical Feedback Network of FPS
2. Other Reference Materials
AN-4134: Design Guidelines for Off-line Forward
Converters Using Fairchild Power Switch (FPS™)
When FPS acts in Burst mode and the Burst operation is
suspected to be a source of noise, this method may be
helpful. If the frequency of Burst mode operation lies in
the range of 2~4KHz, adjusting the feedback loop can
shift the Burst operation frequency. In order to reduce
the Burst operation frequency, increase a feedback gain
capacitor (CF), optocoupler supply resistor (RD) and
feedback capacitor (CB) and decrease a feedback gain
resistor (RF) as shown in Figure 12.
AN-4137:Design Guidelines for Off-line Flyback
Converters Using Fairchild Power Switch (FPS)
AN-4140: Transformer Design Consideration for Off-line
Flyback Converters using Fairchild Power Switch (FPS™)
AN-4141: Troubleshooting and Design Tips for Fairchild
Power Switch (FPS™) Flyback Applications
AN-4147: Design Guidelines for RCD Snubber of
Flyback
AN-4148: Audible Noise Reduction Techniques for FPS
Applications
FSDH0170RNB/FSDH0270RNB/FSDH0370RNB Rev. 1.0.2
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FSDH0170RNB/FSDH0270RNB/FSDH0370RNB Green Mode Fairchild Power Switch (FPS™)
Application Tips
Application
Output power
Input voltage
Output Voltage (Max current)
PC Auxiliary Power Supply
(Using FSDH0270RNB)
15W
Universal input
(85–265 Vac)
5V (3A)
Features
Key Design Notes
„ High efficiency (> 78% at 115 Vac and 230 Vac input)
„ The delay time for overload protection is designed to
„ Low standby mode power consumption (< 0.8W at
be about 30ms with C8 of 47nF. If faster/slower triggering of OLP is required, C8 can be changed to a
smaller/larger value (e.g. 100nF for about 60ms).
„ ZP1, DL1, RL1, RL2, RL3, RL4, RL5, RL7, QL1, QL2,
and CL9 build a Line Under Voltage Lock Out block
(UVLO). The zener voltage of ZP1 determines the
input voltage which makes FPS turn on. RL5 and DL1
provide a reference voltage from VCC. If the input voltage divided by RL1, RL2, and RL4 is lower than the
zener voltage of DL1, QL1 and QL2 turn on and pull
down Vfb to ground.
„ This evaluation board and corresponding test report
can be provided.
230 Vac input and 0.5W load)
„ Enhanced system reliability through various protection
functions
„ Low EMI through frequency modulation
„ Internal soft-start (10ms)
„ Line UVLO function can be achieved using external
component
FSDH0170RNB/FSDH0270RNB/FSDH0370RNB Rev. 1.0.2
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FSDH0170RNB/FSDH0270RNB/FSDH0370RNB Green Mode Fairchild Power Switch (FPS™)
Typical Application Circuit
R6
2.4 1W
D2
1N4007
D3
D5
1N4007
D4
L1
4.7k
330uH
R2
C2
22uF 400V
C3
22uF 400V
ZR1
open
ZD1
open
C10
1nF 250V
ZP1
1N4762
J1
FB
C7
47uF 25V
D6
ZDS1
P6KE180A
R14
30
R10
DS1
1N4007
1N4007
R12
open
C1
2
10 EE2229
6
2.2nF AC250V
T1
1
3
4
5
RS1
9
D1
CS1
C9
1.5nF
C4
1000uF 16V
SB540
1000uF 16V
560
R3
U2
TL431A
1
2
3
2
0
5
open
Vstr
R8
Ipk
L3
6
4
1N4007
30k
Drain
R13
Vfb
open
7
3
C8
8
Drain
47nF
Drain
Vcc
ZD2
open
GND
2
1N4007
RL5
J3
open
0
U1B
H11A817
1
RL1 1Mega
DL1
1N5233B
J2
QL2
KSP2222A
U3
CON1
QL1
KSP2907A
RL3
1k
RL7
40k
FSDH0x70RNB
1
2
3
Input
RL2
1Mega
RL4
120k
CL9
10uF 50V
4
3
500
R4
U1A
C6
47nF
H11A817
1
L2
J4
0
R9
1uH
10k
J5
open
R5
1.2k 1%
R11
1.2k 1%
C5
470uF 10V
1
CON2
2
Output
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FSDH0170RNB/FSDH0270RNB/FSDH0370RNB Rev. 1.0.2
FSDH0170RNB/FSDH0270RNB/FSDH0370RNB Green Mode Fairchild Power Switch (FPS™)
1. Schematic
2T 1T
Top
2T
2T
Tape 1T(25um)
1T
2mm
5
EE2229
1
9, 10
10
9
N p/2
N p/2
Na
2
3
6, 7
N 5V
4
7
6
5
3mm
Bottom
Pin
1
2
4
2 3
3. Winding Specification
Np/2
Pin (S → F)
Wire
Turns
Winding Method
3→2
0.3ϕ × 1
72
Solenoid winding
0.25ϕ × 2
22
Solenoid winding
0.65ϕ × 2
8
Solenoid winding
0.3ϕ × 1
72
Solenoid winding
Insulation: Polyester Tape t = 0.025mm, 1 Layers
4→5
Na
Insulation: Polyester Tape t = 0.025mm, 2 Layers
6, 7 → 9, 10
N5V
Insulation: Polyester Tape t = 0.025mm, 2 Layers
2→1
Np/2
Insulation: Polyester Tape t = 0.025mm, 2 Layers
4. Electrical Characteristics
Pin
Spec.
Remark
Inductance
1–3
1.20mH ± 5%
100kHz, 1V
Leakage
1–3
< 30µH Max
Short all other pins
5. Core & Bobbin
Core: EE2229 (Material: PL-7, Ae = 35.7 mm2 )
Bobbin: 10 pin
FSDH0170RNB/FSDH0270RNB/FSDH0370RNB Rev. 1.0.2
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FSDH0170RNB/FSDH0270RNB/FSDH0370RNB Green Mode Fairchild Power Switch (FPS™)
2. Transformer Schematic Diagram
Part Number
Value
Quantity
Description (Manufacturer)
C6, C8
47nF
2
Ceramic Capacitor
C1
2.2nF (250V)
1
AC Ceramic Capacitor
C10
1nF (250V)
1
Film Capacitor
CS1
1.5nF (50V)
1
SMD Ceramic Capacitor
C2, C3
22µF (400V)
2
Low Impedance Electrolytic Capacitor
KMX series (Samyoung Elec.)
C4, C9
1000µF (16V)
2
Low ESR Electrolytic Capacitor
NXC series (Samyoung Elec.)
C5
470µF (10V)
1
Low ESR Electrolytic Capacitor
NXC series (Samyoung Elec.)
C7
47µF (25V)
1
General Electrolytic Capacitor
CL9
10µF (50V)
1
General Electrolytic Capacitor
L1
330µH
1
Inductor
L2
1µH
1
Inductor
R6
2.4 (1W)
1
Fusible Resistor
J1
FB
1
Ferrite Beads
J2, J4, L3
0
3
Jumper
R2
4.7k
1
Resistor
R3
560
1
Resistor
R4
500
1
Resistor
R5, R11
1.2k(1%)
2
Resistor
R9
10k
1
Resistor
R10
2
1
Resistor
R14
30
1
Resistor
RL3
1k
1
Resistor
RL1, RL2
1 Mega
2
Resistor
RL4
120k
1
Resistor
RL5
30k
1
Resistor
RL7
40k
1
Resistor
RS1
9
1
Resistor
U1
H11A817
1
Optocoupler (Fairchild Semiconductor)
U2
TL431A
1
Shunt Regulator (Fairchild Semiconductor)
U3
FSDH0x70RNB
1
FPSTM (Fairchild Semiconductor)
QL1
KSP2907A
1
PNP Transistor (Fairchild Semiconductor)
QL2
KSP2222A
1
NPN Transistor (Fairchild Semiconductor)
D2, D3, D4, D5, D6, DS1
1N4007
6
Diode (Fairchild Semiconductor)
D1
SB540
1
Schottky Diode (Fairchild Semiconductor)
DL1
1N5233B
1
Zener Diode (Fairchild Semiconductor)
ZP1
1N4762
1
Zener Diode
ZDS1
P6KE180A
1
TVS (Fairchild Semiconductor)
T1
EE2229
1
PL-7 Core (Samwha Elec.)
FSDH0170RNB/FSDH0270RNB/FSDH0370RNB Rev. 1.0.2
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FSDH0170RNB/FSDH0270RNB/FSDH0370RNB Green Mode Fairchild Power Switch (FPS™)
6. Demo Circuit Part List
FSDH0170RNB/FSDH0270RNB/FSDH0370RNB Green Mode Fairchild Power Switch (FPS™)
7. Layout
7.1 Top image of PCB
7.2 Bottom image of PCB
FSDH0170RNB/FSDH0270RNB/FSDH0370RNB Rev. 1.0.2
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8-Pin DIP
FSDH0170RNB/FSDH0270RNB/FSDH0370RNB Rev. 1.0.2
Dimemsions in millimeters
18
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FSDH0170RNB/FSDH0270RNB/FSDH0370RNB Green Mode Fairchild Power Switch (FPS™)
Package Dimensions
The following are registered and unregistered trademarks Fairchild Semiconductor owns or is authorized to use and is
not intended to be an exhaustive list of all such trademarks.
ACEx™
FAST®
ActiveArray™
FASTr™
Bottomless™
FPS™
Build it Now™
FRFET™
CoolFET™
GlobalOptoisolator™
CROSSVOLT™ GTO™
DOME™
HiSeC™
EcoSPARK™
I2C™
E2CMOS™
i-Lo™
EnSigna™
ImpliedDisconnect™
FACT™
IntelliMAX™
FACT Quiet Series™
Across the board. Around the world.™
The Power Franchise®
Programmable Active Droop™
ISOPLANAR™
LittleFET™
MICROCOUPLER™
MicroFET™
MicroPak™
MICROWIRE™
MSX™
MSXPro™
OCX™
OCXPro™
OPTOLOGIC®
OPTOPLANAR™
PACMAN™
POP™
Power247™
PowerEdge™
PowerSaver™
PowerTrench®
QFET®
QS™
QT Optoelectronics™
Quiet Series™
RapidConfigure™
RapidConnect™
μSerDes™
ScalarPump™
SILENT SWITCHER®
SMART START™
SPM™
Stealth™
SuperFET™
SuperSOT™-3
SuperSOT™-6
SuperSOT™-8
SyncFET™
TCM™
TinyLogic®
TINYOPTO™
TruTranslation™
UHC™
UltraFET®
UniFET™
VCX™
Wire™
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.
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:
2. A critical component is any component of a life
1. Life support devices or systems are devices or
support device or system whose failure to perform can
systems which, (a) are intended for surgical implant into
be reasonably expected to cause the failure of the life
the body, or (b) support or sustain life, or (c) whose
support device or system, or to affect its safety or
failure to perform when properly used in accordance
with instructions for use provided in the labeling, can be
effectiveness.
reasonably expected to result in significant injury to the
user.
PRODUCT STATUS DEFINITIONS
Definition of Terms
Datasheet Identification
Product Status
Definition
Advance Information
Formative or
In Design
This datasheet contains the design specifications for
product development. Specifications may change in
any manner without notice.
Preliminary
First Production
This datasheet contains preliminary data, and
supplementary data will be published at a later date.
Fairchild Semiconductor reserves the right to make
changes at any time without notice in order to improve
design.
No Identification Needed
Full Production
This datasheet contains final specifications. Fairchild
Semiconductor reserves the right to make changes at
any time without notice in order 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. I18
FSDH0170RNB/FSDH0270RNB/FSDH0370RNB Rev. 1.0.2
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FSDH0170RNB/FSDH0270RNB/FSDH0370RNB Green Mode Fairchild Power Switch (FPS™)
TRADEMARKS