FAN7602 Green Current Mode PWM Controller
November 2006
FAN7602
Green Current Mode PWM Controller
Features
Green Current Mode PWM Control
Fixed 65kHz Operation with Frequency Modulation
Internal High-Voltage Start-up Switch
Burst Mode Operation
Line Voltage Feed Forward to Limit Maximum Power
Line Under-Voltage Protection
Latch Protection & Internal Soft-Start (10ms) Function
Overload Protection
Over-Voltage Protection
Low Operation Current: Typical 1mA
8-pin DIP/SOP
Description
The FAN7602 is a green current mode PWM controller. It
is specially designed for off-line adapter application,
DVDP, VCR, LCD monitor application, and auxiliary
power supplies.
The internal high-voltage start-up switch and the burst-
mode operation reduce the power loss in standby mode.
Because of the internal start-up switch and the burst
mode, it is possible to supply 0.5W load, limiting the
input power to under 1W when the input line voltage is
265V
AC
. On no-load condition, the 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 and
the frequency modulation technique reduces EMI.
The FAN7602 includes various protections for the sys-
tem reliability and the internal soft-start prevents the out-
put voltage overshoot 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
FAN7602N
FAN7602M
FAN7602MX
-25°C to +125°C
Yes
Operating Temp.
Range
Pb-Free
Package
8-DIP
8-SOP
Packing Method
Rail
Rail
Tape & Reel
Marking
Code
FAN7602
FAN7602
FAN7602
© 2006 Fairchild Semiconductor Corporation
FAN7602 Rev. 1.0.2
www.fairchildsemi.com
FAN7602 Green Current Mode PWM Controller
Typical Application Diagram
FAN7602
FAN7602 Rev. 02
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
65kHz Clock
with
Frequency
Modulation
PWM
Block
Driver
Circuit
Plimit
Offset
Delay
Circuit
5 OUT
3 CS/FB
0.95V/0.88V
Latch/
Plimit
2
4V
Latch
OLP
Plimit
Offset
Soft-Start
PWM+
Soft-
Start
Power Limit
Plimit
Offset
Plimit
Offset
Generator
OLP
4 GND
FAN7602 Rev. 03
Figure 2. Functional Block Diagram of FAN7602
© 2006 Fairchild Semiconductor Corporation
FAN7602 Rev. 1.0.2
2
www.fairchildsemi.com
FAN7602 Green Current Mode PWM Controller
Pin Assignments
V
str
8
NC
7
V
CC
6
OUT
5
FAN7602
YWW
1
LUVP
2
Latch/
Plimit
3
CS/FB
4
GND
FAN7602 Rev. 03
Figure 3. Pin Configuration (Top View)
Pin Definitions
Pin Number
1
2
Pin Name
LUVP
Latch/Plimit
Pin Function 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 Over-Current Protection (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
CS/FB
4
5
GND
OUT
6
7
8
V
CC
NC
V
str
© 2006 Fairchild Semiconductor Corporation
FAN7602 Rev. 1.0.2
3
www.fairchildsemi.com
FAN7602 Green Current Mode PWM Controller
Absolute Maximum Ratings
The “Absolute Maximum Ratings” are those values beyond which the safety of the device cannot be guaranteed. The
device should not be operated at these limits. The parametric values defined in the Electrical Characteristics tables are
not guaranteed at the absolute maximum ratings.
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
300
500
Unit
V
mA
V
V
V
V
°C
°C
°C
W
kV
V
V
Thermal Impedance
Symbol
θ
JA(1)
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
© 2006 Fairchild Semiconductor Corporation
FAN7602 Rev. 1.0.2
4
www.fairchildsemi.com
FAN7602 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
st
I
CC
T
SS
F
OSC
ΔF
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
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
(2)
Operating Frequency
Frequency Modulation
CS/FB Threshold Voltage
Propagation Delay to Output
(2)
Maximum Duty Cycle
Minimum Duty Cycle
Burst On Threshold Voltage
Burst Off Threshold Voltage
Offset Gain
Output Voltage High
Output Voltage Low
Rising Time
(2)
Falling Time
(2)
Condition
V
str
= 30V, T
A
= 25°C
V
CC
increasing
V
CC
decreasing
Min.
0.7
11
7
3.6
Typ.
1
12
8
4
250
1
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
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
±2
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, Isource = 100mA
T
A
= 25°C, Isink = 100mA
T
A
= 25°C, Cl = 1nF
T
A
= 25°C, Cl = 1nF
0.84
0.77
0.12
11.5
0.95
0.88
0.16
12
1
45
35
1.06
0.99
0.20
14
2.5
150
150
V
V
ns
ns
POWER LIMIT SECTION
OUTPUT SECTION
2. These parameters, although guaranteed by design, are not tested in production.
© 2006 Fairchild Semiconductor Corporation
FAN7602 Rev. 1.0.2
5
www.fairchildsemi.com
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