SAMWIN SW 8800

SAMWIN
SW 8800
Semiconductors
SW 04-5-20-D
V1.01
GREEN POWER
OFF LINE SMPS PRIMARY SWITCHE
Features
z DVD/VCD power supplies
z 85v to 265v wide range AC voltage input
z Electromagnetic Oven power supplies
z A 700v MOSFET on the same silicon chip
z Air Conditioner power supplies
z Auto start up with high voltage current source
z STB power supplies
z PWM with current mode control
z AC/DC LED Driver Applications
z 9v to 38v wide range VCC voltage
z Fixed 60KHz switching frequency
Package
z Automatic skip cycle mode in low load condition.
z Over temperature, over current and over voltage
protection
z Auxiliary under voltage lockout with hysteresis
Type
SO8
DIP8
European (195-265 Vac)
8W
13W
US (85-265 Vac)
5W
8W
Applications
z Power AC/DC Adapters for Chargers
Typical Application Circuit
Samwin
SW 8800
7-1
SAMWIN
SW 8800
Semiconductors
SW 04-5-20-D
V1.01
Pin Configuration
Pin Definitions
Pin Number
Pin Name
1,2
GND
3
COMP
Pin Function Description
Sense FET source terminal on primary side and internal control
ground.
Feedback input defines the peak drain MOSFET current.
Positive supply voltage input. Although connected to an auxiliary
transformer winding, current is supplied from SW via an internal
4
switch during startup (see Internal Block Diagram section). It is not
VCC
until VCC reaches them UVLO upper threshold (14.5V) that the
internal start-up switch opens and device power is supplied via the
auxiliary transformer winding.
5,6,7,8
The SW pin is designed to connect directly to the primary lead of the
SW
transformer and is capable of switching a maximum of 700V.
Internal Block Diagram
VCC
SW
STARTUP SOURCE
OTP
STARTUP
CONIROL
+
UVLO CONTROL
+
R1
R2
R3
R4
PWMLATCHER
OUTPUT
DRIVER
Q
FF
M2
M1
S
OVP DETECT
OSCILITOR
LEB
+
REFERENCE
PREREGULATOR
R1
R2
BLAS
7-2
COMP
GND
SAMWIN
SW 8800
Semiconductors
SW 04-5-20-D
V1.01
Absolute Maximum Ratings
(Ta=25°C, unless otherwise specified)
Symbol
Parameter
Value
Unit
VSW
SW to GND Voltage (Tj=25-125°C)
-0.3 ... 730
V
ID
Continuous VDMOS Drain Current
Internally limited
A
VCC
Supply Voltage
0...50
V
ICOMP
Feedback Current
3
mA
200
V
2000
V
Internally limited
°C
VESDMM
VESDHBM
Electrostatic Discharge:
Machine Model ((R=0Ω; C=200pF)
Electrostatic Discharge:
HBM
Tj
Junction Operating Temperature
Tc
Case Operating Temperature
-40 to 150
°C
Tstg
Storage Temperature
-55 to 150
°C
Electrical Characteristic (Power)
Symbol
Parameter
BVDSS
VDMOS Breakdown Voltage
IDSS
Zero Gate Voltage Drain Current
RDSON
Static Drain-Source on Resistance
Tr
Rise Time
Tf
Fall Time
COSS
VDMOS Drain Capacitance
Condition
ID=1mA;
VCOMP=2V
Min.
Typ.
730
VCOMP=2V;
ID=0.4A;
ID=0.1A;
VIN=300V
ID=0.2A;
VIN=300V
VDS=25V
7-3
Unit
V
VDS=500V;
VGS=10V
Max.
27
100
μA
30
Ω
50
ns
100
40
pF
SAMWIN
SW 8800
Semiconductors
SW 04-5-20-D
V1.01
Electrical Characteristic (Control)
(Ta=25°C, VCC=18V, unless otherwise specified)
Symbol
Parameter
Condition
Min.
Typ.
Max.
Unit
UVLO SECTION
VSTART
VCC Start Threshold Voltage
VCOMP=0V
13
14.5
16
V
VSTOP
VCC Stop Threshold Voltage
VCOMP=0V
7
8
9
V
VHYS
VCC Threshold Hysteresis
5.8
6.5
7.2
V
54
60
66
kHz
±5
±10
%
OSCILLATOR SECTION
FOSC
ΔF/ΔT
VSTOP≤VCC≤35
Initial Accuracy
Frequency
Change
V; 0≤Tj≤ 100°C
With
Temperature
-25°C ≤ Tj
≤ +85°C
FEEDBACK SECTION
ICOMP
Feedback Shutdown Current
RCOMP
COMP Pin Input Impedance
Tj=25°C,
VCOMP = 0V
ID=0mA
0.9
mA
1.2
kΩ
CURRENT LIMIT(SELF-PROTECTION)SECTION
GID
ICOMP to ID Current Gain
320
ILIM
Peak Current Limit
Tj = 25°C
TD
Current Sense Delay to Turn-Off
ID=0.2A
TB
TONMIN
0.32
0.40
0.48
A
200
ns
Blanking Time
500
ns
Minimum Turn On Time
700
ns
-
°C
PROTECTION SECTION
TSD
Thermal Shutdown Temperature
THYST
Thermal Shutdown Hysteresis
VOVP
Over Voltage Protection
140
170
40
38
42
°C
46
V
SUPPLY CURRENT SECTION
ICH
ICHOFF
Startup Charging Current
Start Up Charging Current
in Thermal Shutdown
1
mA
VCC=5V;
0.2
VDS=100V
mA
Tj > TSD
Operating Supply Current
IOP0
(Control Part Only)
VCOMP = 0V
4.5
VCOMP = 2V
3
mA
Switching
Operating Supply Current
IOP1
(Control Part Only)
Not Switching
7-4
5
mA
SAMWIN
SW 8800
Semiconductors
SW 04-5-20-D
V1.01
Functional Description
1.
MOSFET delivers a sense current which is
Startup
This device includes a high voltage start up
proportional to the main current. R2 receives this
current source connected on the SW of the device.
current and the current coming from the COMP
As soon as a voltage is applied on the input of the
pin. The voltage across R2 VR2 is then compared
converter, this start up current source is activated
to a fixed reference voltage. The MOSFET is
and to charge the VCC capacitor as long as VCC
switched off when VR2 equals the reference
is lower than VSTART. When reaching VSTART,
voltage.
the start up current source is cut off by
3. Leading Edge Blanking (LEB)
UVLO&TSD and the device begins to operate by
At the instant the internal Sense FET is turned on,
turning on and off its main power MOSFET. As
there usually exists a high current spike through
the COMP pin does not receive any current from
the Sense FET, caused by the primary side
the opto-coupler, the device operates at full
capacitance and secondary side rectifier diode
current capacity and the output voltage rises until
reverse recovery.
reaching the regulation point where the secondary
sense resistor would lead to false feedback
loop begins to send a current in the opto-coupler.
operation in the current mode PWM control. To
At this point, the converter enters a regulated
counter this effect, the device employs a leading
operation where the COMP pin receives the
edge blanking (LEB) circuit. This circuit inhibits
amount of current needed to deliver the right
the PWM comparator for a short time (typically
power on secondary side.
500ns) after the Sense FET is turned on.
Fig 1
Startup circuit
Excessive voltage across the
4. Under Voltage Lock Out
Once fault condition occurs,
switching
is
terminated and the Sense FET remains off. This
causes VCC to fall. When VCC reaches the
UVLO stop voltage, 8V, the protection is reset
and the internal high voltage current source
charges the VCC capacitor. When VCC reaches
the UVLO start voltage, 14.5V, the device
resumes its normal operation. In this manner, the
2. Feedback
A feedback pin controls the operation of the
device.
Unlike
conventional
PWM
control
circuits which use a voltage input, the COMP pin
auto-restart can alternately enable and disable the
switching of the power Sense FET until the fault
condition is eliminated.
5. Thermal Shutdown (TSD)
The Sense FET and the control IC are integrated
in the same chip, making it easier for the control
IC to detect the temperature of the Sense FET.
When the temperature exceeds approximately
170°C, thermal shutdown is activated, the device
turn off the Sense FET and the high voltage
current source to charge VCC. The device will go
is sensitive to current. Figure 2 presents the
internal current mode structure. The Power
back
to work when
the
lower
temperature about 140°C is reached.
7-5
threshold
SAMWIN
SW 8800
Semiconductors
SW 04-5-20-D
V1.01
6. Over Voltage Protection (OVP)
secondary side. In order to prevent this situation,
In case of malfunction in the secondary side
an over voltage protection (OVP) circuit is
feedback circuit, or feedback loop open caused by
employed. If VCC exceeds 42V, OVP circuit is
a defect of solder, the current through the
activated resulting in termination of the switching
opto-coupler transistor becomes almost zero.
operation. In order to avoid undesired activation
Because excess energy is provided to the output,
of OVP during normal operation, VCC should be
the output voltage may exceed the rated voltage,
properly designed to be below 42V.
resulting in the breakdown of the devices in the
Package Dimensions（DIP8）
Size
Size
Min(mm)
Max(min)
symbol
Min(mm)
Max(min)
symbol
A
9.30
9.50
C2
0.50
A1
1.524
C3
3.3
A2
0.39
C4
1.57TYP
A3
2.54
D
8.2
8.8
A4
0.66TYP
D1
0.2
0.35
A5
0.99TYP
D2
7.62
7.87
B
6.3
Θ1
8ºTYP
C
7.2
Θ2
8ºTYP
C1
3.3
Θ3
5ºTYP
0.53
6.5
3.5
C1
C
1
θ
C4
D2
C2
C3
2
θ
A5
A1
A2
A3
A4
B
A
7-6
D1
θ
3
D
SAMWIN
SW 8800
Semiconductors
SW 04-5-20-D
V1.01
IMPORTANT NOTICE
Samwin Microelectronics Co. Ltd. reserves the right to make changes without further notice to any
products or specifications herein. Samwin Microelectronics Co. Ltd. does not assume any responsibility
for use of any its products for any particular purpose, nor does Samwin Microelectronics Co. Ltd assume
any liability arising out of the application or use of any its products or circuits. Samwin Microelectronics
Co. Ltd does not convey any license under its patent rights or other rights nor the rights of others.
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