FAN7602B — Green Current-Mode PWM Controller
March 2007
FAN7602B
Green Current-Mode PWM Controller
Features
Green Current-Mode PWM Control
Fixed 65kHz Operation
Internal High-Voltage Start-up Switch
Burst-Mode Operation
Line Voltage Feedforward to Limit Maximum Power
Line Under-Voltage Protection
Latch Protection & Internal Soft-Start (10ms) Function
Overload Protection
Over-Voltage Protection
Low Operation Current: 1mA Typical
8-pin DIP/SOP
Description
The FAN7602B is a green current-mode PWM controller.
It is specially designed for off-line adapter applications;
DVDP, VCR, LCD monitor applications; and auxiliary
power supplies.
The internal high-voltage start-up switch and the burst-
mode operation reduce the power loss in standby mode.
As a result, it is possible to supply 0.5W load, limiting the
input power under 1W when the input line voltage is
265V
AC
. On no-load condition, input power is under 0.3W.
The maximum power can be limited constantly, regard-
less of the line voltage change, using the power limit
function.
The switching frequency is internally fixed at 65kHz.
The FAN7602B includes various protections for the sys-
tem reliability and the internal soft-start prevents the out-
put voltage over-shoot at start-up.
Applications
Adapter
LCD Monitor Power
Auxiliary Power Supply
Related Application Notes
AN6014
-
Green Current Mode PWM Controller
FAN7602
Ordering Information
Part Number
FAN7602BN
FAN7602BM
FAN7602BMX
-25°C to +125°C
Yes
Operating Temp.
Range
Pb-Free
Package
8-DIP
8-SOP
Packing Method
Rail
Rail
Tape & Reel
Marking
Code
FAN7602B
FAN7602B
FAN7602B
© 2007 Fairchild Semiconductor Corporation
FAN7602B Rev. 1.0.0
www.fairchildsemi.com
FAN7602B — Green Current-Mode PWM Controller
Typical Application Diagram
FAN7602B
Figure 1. Typical Flyback Application
Internal Block Diagram
V
STR
8
6 V
CC
LUVP
1
2V/1.5V
LUVP
OLP
OVP
Latch
Auto Restart
Protection
Latch
Protection
Reset
Circuit
V
CC
OVP
SS End
19V
5V Ref
UVLO
12V/8V
10ms
Soft Start
SS End
PWM
Block
65kHz clock
Delay
Circuit
Latch/
Plimit
0.95V/0.88V
2
4V
Plimit
Offset
Generator
Plimit
Offset
Soft
Start
Latch
PWM+
OLP
Soft
Start
Driver
Circuit
Plimit
Offset
5 OUT
3 CS/FB
Power Limit
Plimit
Offset
OLP
4 GND
Figure 2. Functional Block Diagram of FAN7602B
© 2007 Fairchild Semiconductor Corporation
FAN7602B Rev. 1.0.0
2
www.fairchildsemi.com
FAN7602B — Green Current-Mode PWM Controller
Pin Assignments
V
STR
8
NC
7
V
CC
6
Out
5
FAN7602B
YWW
1
LUVP
2
Latch/
Plimit
3
CS/FB
4
GND
Figure 3. Pin Configuration (Top View)
Pin Definitions
Pin #
1
2
Name
LUVP
Latch/Plimit
Description
Line Under-Voltage Protection Pin.
This pin is used to protect the set when the
input voltage is lower than the rated input voltage range.
Latch Protection and Power Limit Pin.
When the pin voltage exceeds 4V, the latch
protection works; the latch protection is reset when the V
CC
voltage is lower than 5V.
For the power limit function, the OCP level decreases as the pin voltage increases.
Current Sense and Feedback Pin.
This pin is used to sense the MOSFET current
for the current mode PWM and OCP. The output voltage feedback information and
the current sense information are added using an external RC filter.
Ground Pin.
This pin is used for the ground potential of all the pins. For proper oper-
ation, the signal ground and the power ground should be separated.
Gate Drive Output Pin.
This pin is an output pin to drive an external MOSFET. The
peak sourcing current is 450mA and the peak sinking current is 600mA. For proper
operation, the stray inductance in the gate driving path must be minimized.
Supply Voltage Pin.
IC operating current and MOSFET driving current are supplied
using this pin.
No Connection.
Start-up Pin.
This pin is used to supply IC operating current during IC start-up. After
start-up, the internal JFET is turned off to reduce power loss.
3
4
5
6
7
8
CS/FB
GND
OUT
V
CC
NC
V
STR
© 2007 Fairchild Semiconductor Corporation
FAN7602B Rev. 1.0.0
3
www.fairchildsemi.com
FAN7602B — Green Current-Mode PWM Controller
Absolute Maximum Ratings
Stresses exceeding the absolute maximum ratings may damage the device. The device may not function or be opera-
ble above the recommended operating conditions and stressing the parts to these levels is not recommended. In addi-
tion, extended exposure to stresses above the recommended operating conditions may affect device reliability. The
absolute maximum ratings are stress ratings only.
Symbol
V
CC
I
OH
, I
OL
V
CS/FB
V
LUVP
V
Latch
V
STR
T
J
T
A
T
STG
P
D
V
ESD_HBM
V
ESD_MM
V
ESD_CDM
Supply Voltage
Parameter
Peak Drive Output Current
CS/FB Input Voltage
LUVP Input Voltage
Latch/Plimit Input Voltage
V
STR
Input Voltage
Operating Junction Temperature
Operating Temperature Range
Storage Temperature Range
Power Dissipation
ESD Capability, Human Body Model
ESD Capability, Machine Model
ESD Capability, Charged Device Model
Value
20
+450/-600
-0.3 to 20
-0.3 to 10
-0.3 to 10
600
150
-25 to 125
-55 to 150
1.2
2.0
200
500
Unit
V
mA
V
V
V
V
°C
°C
°C
W
kV
V
V
Thermal Impedance
Symbol
θ
JA
Note:
1. Regarding the test environment and PCB type, please refer to JESD51-2 and JESD51-10.
Parameter
Thermal Resistance, Junction-to-Ambient
8-DIP
Value
100
Unit
°C/W
© 2007 Fairchild Semiconductor Corporation
FAN7602B Rev. 1.0.0
4
www.fairchildsemi.com
FAN7602B — Green Current-Mode PWM Controller
Electrical Characteristics
V
CC
= 14V, T
A
= -25°C~125°C, unless otherwise specified
Symbol
START UP SECTION
I
STR
V
th
(start)
V
th
(stop)
HY(uvlo)
I
STR
I
CC
t
SS
f
OSC
V
CS/FB1
t
D
D
MAX
D
MIN
V
CS/FB2
V
CS/FB3
K
Plimit
V
OH
V
OL
t
R
t
F
V
Latch
t
OLP
t
OLP_ST
V
OLP
V
LUVPoff
V
LUVPon
V
OVP
Note:
Parameter
V
STR
Start-up Current
Start Threshold Voltage
Stop Threshold Voltage
UVLO Hysteresis
Start-up Supply Current
Operating Supply Current
Soft-Start Time
(1)
Operating Frequency
CS/FB Threshold Voltage
Propagation Delay to Output
(1)
Maximum Duty Cycle
Minimum Duty Cycle
Burst On Threshold Voltage
Burst Off Threshold Voltage
Offset Gain
Output Voltage High
Output Voltage Low
Rising Time
(1)
Falling Time
(1)
Latch Voltage
Overload Protection Time
(1)
Overload Protection Time at Start-
up
Overload Protection Level
Line Under-Voltage Protection On
to Off
Line Under-Voltage Protection Off
to On
Over-Voltage Protection
Condition
V
STR
= 30V, T
A
= 25°C
V
CC
increasing
V
CC
decreasing
Min.
0.7
11
7
3.6
Typ.
1.0
12
8
4.0
250
1.0
Max.
1.4
13
9
4.4
320
1.5
15
73
1.1
150
80
0
Unit
mA
V
V
V
μA
mA
ms
kHz
V
ns
%
%
V
V
UNDER VOLTAGE LOCK OUT SECTION
SUPPLY CURRENT SECTION
T
A
= 25°C
Output no switching
5
V
CS/FB
= 0.2V, T
A
= 25°C
T
A
= 25°C
59
0.9
70
SOFT-START SECTION
10
65
1.0
100
75
PWM SECTION
BURST MODE SECTION
T
A
= 25°C
T
A
= 25°C
V
Latch/Plimit
= 2V, T
A
= 25°C
T
A
= 25°C, I
source
= 100mA
T
A
= 25°C, I
sink
= 100mA
T
A
= 25°C, C
L
= 1nF
T
A
= 25°C, C
L
= 1nF
3.6
20
30
0.84
0.77
0.12
11.5
0.95
0.88
0.16
12.0
1.0
45
35
4.0
22
37
0
T
A
= 25°C
T
A
= 25°C
T
A
= 25°C
1.9
1.4
18
2.0
1.5
19
1.06
0.99
0.20
14.0
2.5
150
150
4.4
24
44
0.1
2.1
1.6
20
V
V
ns
ns
V
ms
ms
V
V
V
V
POWER LIMIT SECTION
OUTPUT SECTION
PROTECTION SECTION
1. These parameters, although guaranteed by design, are not tested in production.
© 2007 Fairchild Semiconductor Corporation
FAN7602B Rev. 1.0.0
5
www.fairchildsemi.com
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