FS7M0880 - Mouser Electronics

FS7M0880 - Mouser Electronics
www.fairchildsemi.com
FS7M0880
Fairchild Power Switch(FPS)
Features
Description
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The Fairchild Power Switch(FPS) product family is specially
designed for an off line SMPS with minimal external
components. The Fairchild Power Switch(FPS) consists of a
high voltage power SenseFET and the current mode PWM controller IC. The PWM controller includes an integrated fixed
oscillator, the under voltage lock out, the leading edge blanking
block, the optimized gate turn-on/turn-off driver, the thermal
shut down protection, the over voltage protection, the temperature compensated precision current sources for loop compensation and an fault protection circuit. Compared to just PWM
controller combined MosFET or RCC switching converter solution, a Fairchild Power Switch(FPS) can reduce total component price, design size, and weight,also simultaneously increase
efficiency, productivity, and system reliability. It has a simple
method of application well suited for cost down design in either
a flyback converter or a forward converter.
Precision Fixed Operating Frequency
FS7M0880(66kHz)
Pulse By Pulse Over Current Limiting
Over Load Protection
Over Voltage Protection (Min. 25V)
Internal Thermal Shutdown Function
Under Voltage Lockout
Internal High Voltage Sense FET
Latch Up Mode
Soft Start
TO-3P-5L
1
1. DRAIN 2. GND 3. VCC 4. FB 5. S/S
Internal Block Diagram
#3 Vcc
Voltage
Ref.
UVLO
#4
Feedback
Vcc
Vcc
5uA
1mA
#4
Drain
Good
Logic
Vck
OSC
S
2.5R
Q
#5
Soft Start
R
R
LEB
Voffset
Sense
5V
Rsense
SenseFET
Reset
7.5V
Reset
#2
Source
GND
S
Thermal
Protection
Q
R
OVP
OCL
Control IC
Rev.1.0.1
©2003 Fairchild Semiconductor Corporation
FS7M0880
Absolute Maximum Ratings
Parameter
Drain-Gate Voltage (RGS=1MΩ)
Gate-Source (GND) Voltage
(2)
Symbol
Value
Unit
VDGR
800
V
VGS
±30
V
IDM
32.0
ADC
EAS
810
mJ
IAS
15
A
Continuous Drain Current (TC=25°C)
ID
8.0
ADC
Continuous Drain Current (TC=100°C)
ID
5.6
ADC
VCC,MAX
30
V
VFB
-0.3 to VSD
V
PD
190
W
Derating
1.54
W/°C
TA
-25 to +85
°C
TSTG
-55 to +150
°C
Drain Current Pulsed
Single Pulsed Avalanche Energy (3)
Avalanche Current
(4)
Maximum Supply Voltage
Input Voltage Range
Total Power Dissipation
Operating Ambient Temperature
Storage Temperature
Note:
1. Tj = 25°C to 150°C
2. Repetitive rating: Pulse width limited by maximum junction temperature
3. L = 24mH, VDD = 50V, RG = 25Ω, starting Tj =25°C
4. L = 13µH, starting Tj = 25°C
2
FS7M0880
Electrical Characteristics (SFET part)
(Ta=25°C unless otherwise specified)
Parameter
Symbol
Condition
Min.
Typ.
Max.
Unit
Drain-Source Breakdown Voltage
BVDSS
VGS=0V, ID=50µA
800
-
-
V
VDS=Max., Rating,
VGS=0V
-
-
50
µA
VDS=0.8Max., Rating,
VGS=0V, TC=125°C
-
-
200
µA
VGS=10V, ID=5.0A
-
1.2
1.5
Ω
VDS=15V, ID=5.0A
1.5
2.5
-
S
-
2460
-
-
210
-
-
64
-
-
-
90
-
95
200
-
150
450
-
60
150
-
-
150
-
20
-
-
70
-
Zero Gate Voltage Drain Current
IDSS
Static Drain-Source On Resistance (note1) RDS(ON)
Forward Transconductance
(note1)
gfs
Input Capacitance
Ciss
Output Capacitance
Coss
Reverse Transfer Capacitance
Crss
Turn On Delay Time
td(on)
Rise Time
Turn Off Delay Time
Fall Time
tr
td(off)
tf
Total Gate Charge
(Gate-Source+Gate-Drain)
Qg
Gate-Source Charge
Qgs
Gate-Drain (Miller) Charge
Qgd
VGS=0V, VDS=25V,
f=1MHz
VDD=0.5BVDSS, ID=8.0A
(MOSFET switching
time are essentially
independent of
operating temperature)
VGS=10V, ID=8.0A,
VDS=0.5BVDSS (MOSFET
switching time are
essentially independent of
operating temperature)
pF
nS
nC
Note:
1. Pulse test: Pulse width ≤ 300µS, duty cycle ≤ 2%
1
2. S = ---R
3
FS7M0880
Electrical Characteristics (CONTROL part) (Continued)
(Ta=25°C unless otherwise specified)
Parameter
Symbol
Condition
Min.
Typ.
Max.
Unit
Start Threshold Voltage
VSTART
-
14
15
16
V
Stop Threshold Voltage
VSTOP
After turn on
8
9
10
V
FOSC
-
60
66
72
kHz
-
±5
±10
%
-
45
50
55
%
UVLO SECTION
OSCILLATOR SECTION
Initial Frequency
Frequency Change With Temperature
(2)
Maximum Duty Cycle
∆F/∆T
-25°C ≤ Ta ≤ +85°C
Dmax
FEEDBACK SECTION
Feedback Source Current
IFB
Ta=25°C, 0V ≤ Vfb ≤ 3V
0.7
0.9
1.1
mA
Shutdown Delay Current
Idelay
Ta=25°C, 5V ≤ Vfb ≤ VSD
4.0
5.0
6.0
µA
SOFT START SECTION
Soft Start Voltage
VSS
VFB =2V
4.7
5.0
5.3
V
Soft Start Current
ISS
Sync & S/S=GND
0.8
1.0
1.2
mA
Vref
Ta=25°C
4.80
5.00
5.20
V
-
0.3
0.6
mV/°C
4.40
5.00
5.60
A
REFERENCE SECTION
Output Voltage (1)
Temperature Stability
(1)(2)
Vref/∆T
-25°C ≤ Ta ≤ +85°C
CURRENT LIMIT (SELT-PROTECTION)SECTION
Peak Current Limit
IOVER
Max. inductor current
PROTECTION SECTION
Thermal Shutdown Temperature (Tj) (1)
°C
TSD
-
140
Over Voltage Protection Voltage
VOVP
-
25
28
31
V
Over Current Protection Voltage
VOCP
-
1.05
1.10
1.15
V
TOTAL DEVICE SECTION
Start Up Current
Operating Supply Current
(Control Part Only)
Shutdown Feedback Voltage
ISTART
VCC=14V
-
40
80
uA
IOP
Ta=25°C
-
8
12
mA
150
250
350
uA
6.9
7.5
8.1
V
Iop(lat)
VSD
After latch,
Vcc=Vstop-0.1V
-
Note:
1. These parameters, although guaranteed, are not 100% tested in production
2. These parameters, although guaranteed, are tested in EDS (wafer test) process
4
FS7M0880
Block Diagram
It can be divided into several large, functional sections:
under voltage lockout circuitry (UVLO); reference voltage;
oscillator (OSC); pulse width modulation (PWM) block;
protection circuits; and gate driving circuits.
described in Fig 2. Although VCC only needs to be set above
9V during operation, it should be set such that OVP does not
execute during an overload condition. For a full load, about
18~20V is appropriate for the VCC voltage and for no load,
about 13~14V.
Start Up
Protection
Input voltage range: 85 ~ 265 V (AC)
When Vac is minimum and it is started by the DC Link bulk
capacitor, the starting resistance is calculated as follows:
The FPS has several self-protection circuits, which can
operate without additional external components, thereby
acquiring reliability without increase in cost. After a
protection circuit comes on, it can completely stop the SMPS
until the cutoff AC power is reconnected (Latch Mode
Protection) or it can make the SMPS operate above the
UVLO by unlatching the control voltage below the ULVO
(Auto Restart Mode Protection).
85 2 – 15
R start = --------------------------- = 1.3MΩ
80µA
When Vac is maximum and it is started by the DC Link Bulk
capacitor, the power loss is calculated as follows:
2
( 265 2 – 15 )
Ploss = -------------------------------------- = 0.1 ( W )
1.3MΩ
Va
265V
UVLO
85V
When it is started by the one-phase of the AC-Lines and Vac
is minimum, the starting resistance is calculated as follows:
R
2 • 85 2 – 15π
= ---------------------------------------- ÷ ( 80µA )
Start
2π
= 38MΩ
When it is started bythe one-phase of the AC_Line and Vac
is maximum, the power loss is calculated as follows:
Va ( rms ) =
2
1 π
------ ( Vp sin t – 15 ) dt
2π o
∫
= 177V ( Vp = 265 2 )
Va ( rms ) 2
( 177 ) 2
= --------------------------- = -----------------P
loss
Rstart
38M
= 82 ( mW )
The starting current across the starting resistor charges the
SPS VCC capacitor. When the VCC becomes greater than the
starting voltage, the SPS starts to switch the built-in
MOSFET. Once it starts, the current in the SPS control IC
abruptly is increased to 7mA, makes it difficult to operate
with the current through the starting resistor. Therefore, after
it starts, the auxiliary winding of the transformer supplies
most of the power to SPS. It is best to use an appropriate size
VCC power capacitor, generally about 33µF, because if it is
too large, the starting time can be delayed. This operation is
Figure 1. Detail of the undervoltage lockout (UVLO)
circuitry in a Fairchild Power Switch. The gate
operating circuit holds in a low state during UVL
thereby maintaining the SenseFET at turnoff.
These two operations are user-command operations, so the
user can select the
operation from the IC or by carefully controlling circuit
constants. The operation and applications for each protection
are described below.
Icc
[mA]
20
7
Power On Reset
Range
0.1
Vcc
6V
9V
Fig 2
15V
Vz
[V]
< Start-up Waveform >
Figure 2. Start-up Waveform
Over Load Protection
In abnormal status of SMPS over load is distinguished from
load short. This happens when a load exceeds a pre-set load
during normal operation. That is, the FPS overload
protection circuit stops the FPS if an instantaneous load
increases and becomes greater than 50W during normal
operation, when the maximum SMPS output had been
pre-set to 30W. In this type of protection, the protection
5
FS7M0880
4uA
0 .9 m A
V fb
Vo
#4
D1
C fb
Cd
D2
V fb *
V z = 3 .9 V
K A 431
7 .5 V
7.5V
3 .9V
3 .0V
0V
t
t1
t2
T im e C o n s ta n t
= 3.5R *C fb
t3
4 u A = C fb * 0 .9 V / t 2
4 u A = C d * 3 .6 V / t3
S h u td o w n
Figure 3. SPS Delayed Shutdown
circuit can perform undesired operations even during
transient state, which lasts until normal operation. As a
measure against this problem, this protection circuit in the
SPS operates after a specified period to determine whether
the condition is a transient or an overload. This is done to
prevent protection circuit operation during a transient state,
which returns normal after a specified period. This operation
is described as follows.
Because the FPS uses the current control mode, it cannot
flow current over the set maximum current, and therefore the
maximum input power is restricted at the characteristic
voltage. Therefore, if the output consumes beyond this
maximum power, VO, shown in the figure below, becomes
less than the set voltage and only the provided minimum
current can flow through KA431. As a result, the secondary
current of the photocoupler becomes almost zero. If all the
SPS’s 0.9mA current source flows through the internal
resistor (2.5R + R ·=· 3k), Vfb becomes approximately 3V,
and the 4µA current starts to charge Cfb. Because the
photocoupler secondary current is almost zero, Vfb
continues to increase until it reaches 7.5V, at which time the
SPS shutsdown. The delay time to shutdown is the time
required to charge Cfb to 4.5V with 4µA and can be easily
set. When Cfb is 10nF(103), t2 is approximately 11.2mS and
when 0.1µF(104) approximately 120ms. With this amount of
the SPS does not shutdown for most transient states. Just
increasing Cfb to obtain a longer delay time can become a
problem, because Cfb is an important parameter for
determining the response speed (Dynamic Response) of the
SMPS. Similarly, Vfb exceeds 3V and the 4uA current starts
to charge the Cfb. At this time, Vfb continues to increase
until it becomes 7.5V, at which time a resistor could be
added between the F/B pin and GND to lengthen the time to
6
SPS shutdown. If a part of delay current go through the
added resistor, the time to shutdown can be lengthened. In
our test the delay shutdown time with Cfb(473) and resistor
(3.9M) is about two times longer than with only Cfb(473).
When Vfb is 7.5V, the current flowing through this 3.9mΩ
resistor is approximately 1.9µA. To obtain the same results,
if a zener diode (about 3.9 ~ 4.7V) in series connection with
a capacitor is parallel-connected to Cfb, as depicted in Fig 3.,
the desired shutdown delay time could be obtained according
to the size of the capacitor.
Over voltage Protection Circuit
The FPS has a self-protection feature against malfunctions,
such as feedback circuit open or short-circuit. When the
feedback terminal short circuits as seen from the primary
side, the feedback terminal voltage becomes zero, and
switching cannot start as a result. If the feedback terminal
opens, then the protection circuit initiates as in the overload
protection circuit. If the feedback terminal looks open due to
a malfunction in the secondary side feedback circuit or a
non-solder, the primary side continues to switch with the set
maximum current until the protection circuit come on;
therefore, it is normal for the secondary side voltage to
become much greater than the rated voltage. If there was no
protection circuit guarding against such conditions, the fuse
can blow or, even more serious, a fire can start. Even if it
does not lead such dire circumstances, the IC connected to
the secondary side without a regulator could be destroyed
(especially the digital IC such as TTL IC etc.) For such
instances, time, the over voltage protection circuit
(protection against feedback circuit abnormalities) starts to
operate in the SPS. In such circumstances, the output
voltage, which increases tremendously, is made proportional
FS7M0880
to the SPS VCC voltage. If VCC exceeds 24 V, the SPS IC
starts the protection circuit. Therefore, VCC should be
appropriately kept below 24V during normal operation.
OCP (Over Current Protection)
OCP Operating
S Q
Latch signal
R
200ns
Rsense
100ns delay
entire
circuit is seriously stressed. Use of a soft start function
avoids such stresses. Figure 6 shows how to implement a
soft start for a Fairchild Power Switch(FPS). At turn on, the
soft start capacitor on pin 5 of the Fairchild Power
Switch(FPS) starts to charge through the 1mA current
source. When the voltage across CS reaches 3V, diode DS
turns off. No more current flows to it from the 1mA current
source. Cs then continues to charge to 5V through the 20kΩ
resistor.
10V
Fairchild Power
Switch(FPS)
OCP time
4uA
R
C
0.9mA
PWM
Comparator
OCP Level
5V
Minimum Turn-on Time
20K
Fiqure 5. OCP Function & Block
#4
The FPS has various built-in, basic protection features. They
are the UVLO (Under Voltage Lock Out), OLP (Over Load
Protection) and OCP (Over Current Protection). However, if
a secondary side diode short or load short occur due to a
worst case condition, such as a maximum input voltage
putting a large strain on the device, another external
component may need to be added. By adding these
requirements in the FPS, superior reliability and
advantageous cost can be achieved.
When gate on signal of the SenseFet is received,
simultaneously the OCP block senses Ipeak through the
sense resistor for 1us. After the OCP block has turned on,
the voltage across the resistor is compared to the pre-set
voltage in the comparator, and, if it takes longer than 200ns
within the allowed comparison time of 1us, then the
comparator produces a high signal, which latches the OCP.
fig 4. shows the OCP latch waveform. When there is a diode
short/load short, the SPS turns on for the minimum turn-on
time. If the instantaneous current is of the form shown in fig
4., the OCP block opens a 1us window to compare the
voltage proportional to the current across the resistor with
the reference voltage and latches. Here, the 100ns delay
after the 200ns is the delay time to SenseFET gate off and is
generated from the comparison of the voltage across the
sense resistor.
#5
CS
Figure 6. Soft Start Circuit.
Note that when the voltage across CS exceeds 3V, The voltage
at the comparator’s inverting terminal no longer follows the
voltage across CS. Instead, it follows the output voltage
feedback signal. In shutdown or protection circuit operation,
capacitor CS is discharged, to enable it to charge from 0V at
restart.
Soft start operation
Normally, the SMPS output voltage increases from start up
with a fixed time constant. This is due to the capacitive
component of the load. At start up, therefore, the feedback
signal applied to the PWM comparator's inverting input
reaches its maximum value (1V), This is because the
feedback loop is effectively open. Also at this time, the
drain current is at its peak value (Ipeak) and maximum
allowable power is being delivered to the secondary load.
With that said, note that when the SMPS pushes maximum
power to the secondary side for this initial fixed time, the
7
FS7M0880
3. Application Note using the SPS
-Flyback Application (100W)
HOT
NTC
47nF
/630V
Bridge
Diode
47kΩ
/2W
220uF
/400V
MBRF2060CT
5MΩ
30uH
UF4007
1KΩ
2200uF
/50V
2200uF
/50V
0.1uF
10Ω
4.7nF
Line
Filter
1.2kΩ
4.7nF
3
1
Vcc Drain
S/S
4.7nF
5
4.7nF
0.45uF
/275Vac
12V / 9A
DC OUTPUT
Q817A
0.45uF
/275Vac
UF4004
7.6kΩ
2kΩ
FUSE:
250V2A
2kΩ
3.3kΩ
KA7M0880
GND
2
47uF
/50V
KA431
1uF
/50V
FB
4
22nF
10nF
Q817A
PRIMARY
GND
185VAC-265VAC
Transformer Specification
2. Winding Specification
No.
PIN(S → F)
WIRE
TURNS
WINDING METHOD
NP/2
1→3
0.4 φ × 1
42
SOLENOID WINDING
N+12V
12 → 13
INSULATION : POLYESTER TAPE t = 0.050mm, 1Layer
14mm × 1
8
COPPER WINDING
INSULATION : POLYESTER TAPE t = 0.050mm, 3Layer
NB
8→7
0.3 φ × 1
9
SOLENOID WINDING
INSULATION : POLYESTER TAPE t = 0.050mm, 1Layer
NP/2
3→4
0.4 φ × 1
42
SOLENOID WINDING
OUTER INSULATION : POLYESTER TAPE t = 0.050mm, 3Layer
3. Electical Characteristic
CLOSURE
PIN
SPEC.
REMARKS
INDUCTANCE
1-4
700uH ±10%
1kHz, 1V
LEAKAGE L
1-4
10uH MAX.
2nd ALL SHORT
4. Core & Bobbin
CORE : EER 4042
BOBBIN : EER4042
8
FS7M0880
-Forward Application (250W)
223
56KΩ 56KΩ
/630V /2W
NTC
/2W
T1
Line Inductor
UF4007
+ 12V / 10A
T13,14
Line
FUSE
Inductor
102
472
220kΩ 470uF
/200V
/1W
UF4007
/275V
0.47uF
T3
2200uF
2200uF
10Ω
/275V
472
/275V
220kΩ
470uF
/1W
/200V
S30SC4M
+ 5V / 26A
L4
T8,9
33kΩ
/0.5W
2.2kΩ
33kΩ
UF4004
T6
/0.5W
3300uF
10Ω
UF4007
1000uF
2.2kΩ
Vcc
Drain
T10,11,12
T7
SP S
5.6kΩ
GN
S.S.
1kΩ
F.B.
D
123
33uF
1uF
/35V
/50V
Q817
820Ω
333
104
Q817
103
KA431
103
Transformer Specification
2. Winding Specification
No.
PIN(S → F)
WIRE
TURNS
WINDING METHOD
NP/2
1→3
0.65 φ × 1
50T
SOLENOID WINDING
N+5V
8, 9 → 10, 11, 12
14mm × 1
4T
COPPER WINDING
N+12V
13, 14 → 9
0.65 φ × 4
5T
SOLENOID WINDING
NP/2
1→3
0.65 φ × 1
50T
SOLENOID WINDING
NVCC
7→6
0.65 φ × 1
6T
SOLENOID WINDING
3. Electical Characteristic
CLOSURE
PIN
INDUCTANCE
1-3
LEAKAGE L
1-3
4. Secondary Inductor(L2) Specipication
Core : Power Core 27 φ 16 Grade
5V : 12T (1 φ × 2)
10V : 27T (1.2 φ × 1)
9
FS7M0880
Package Dimensions
TO-3P-5L
10
FS7M0880
Package Dimensions (Continued)
TO-3P-5L(Forming)
11
FS7M0880
Ordering Information
Product Number
FS7M0880TU
FS7M0880YDTU
Package
TO-3P-5L
TO-3P-5L(Forming)
Rating
Fosc
800V, 8A
67kHz
TU : Non Forming Type
YDTU : Forming type
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 THE PRESIDENT 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.
www.fairchildsemi.com
8/25/03 0.0m 001
Stock#DSxxxxxxxx
 2003 Fairchild Semiconductor Corporation
This datasheet has been download from:
www.datasheetcatalog.com
Datasheets for electronics components.
Mouser Electronics
Authorized Distributor
Click to View Pricing, Inventory, Delivery & Lifecycle Information:
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FS7M0880YDTU FS7M0880TU
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