FAN7601B — Green Current Mode PWM Controller
May 2012
FAN7601B
Green Current Mode PWM Controller
Features
Green Current Mode PWM Control
Low Operating Current: Maximum 4mA
Burst Mode Operation
Internal High-Voltage Startup Switch
Under-Voltage Lockout (UVLO): 12V/8V
Latch Protection and Soft-Start Function
Over-Voltage Protection: 19V
Operating Frequency up to 300kHz
Description
The FAN7601B is a programmable frequency green
current mode PWM controller. It is specially designed for
the offline adapter applications and the auxiliary power
supplies that require high efficiency at light load and no
load. The internal high-voltage startup switch and burst
mode reduce the power loss.
FAN7601B includes protections, such as latch protection
and over-voltage protection. The latch protection can be
used for over-voltage protection, thermal protection, and
others. The soft-start prevents the output voltage
overshoot at startup.
Maximum Duty Cycle: 95%
Applications
Offline Adapter Applications
Auxiliary Power Supplies
Related Resources
AN4129 — Green Current Mode PWM
Controller FAN7601
Ordering Information
Part Number
FAN7601BM
FAN7601BMX
FAN7601BGX
-40°C to +150°C
Operating
Junction
Temperature
Top Mark
7601B
7601B
7601B
Package
8-SOP
8-SOP
10-SSOP
Packing Method
Rail
Tape & Reel
Tape & Reel
© 2008 Fairchild Semiconductor Corporation
FAN7601B • Rev. 1.0.3
www.fairchildsemi.com
FAN7601B — Green Current Mode PWM Controller
Block Diagram
V
REF
(10)
8
V
STR
(1)
1
7
5V Ref
R
t
/C
t
(5)
4
OSC
UVLO
V
REF
12µA
S
Q
R
6 OUT
(7)
Enable
Startup
Circuit
OVP
V
CC
(8)
+
−
19V
+
−
12V/8V
Latch/SS
3
(4)
1.5V
OVP
+
−
2.5V
S
Q
R
Delay
Circuit
+
−
0.97V/0.9V
2 CS/FB
(3)
1V
GND
(6)
5
+
−
Startup
Circuit
Reset
Circuit
+
−
−
Latch/SS
1V
Figure 1. Internal Block Diagram
Note:
1. ( ) is 10-SSOP Pin Number.
© 2008 Fairchild Semiconductor Corporation
FAN7601B • Rev.1.0.3
www.fairchildsemi.com
2
FAN7601B — Green Current Mode PWM Controller
Pin Configurations
Figure 2. 8-Pin Configuration (Top View)
Figure 3. 10-Pin Configuration (Top View)
Pin Definitions
Pin # (8-Pin)
1
2
3
4
5
6
7
8
Pin # (10-Pin)
1
3
4
5
6
7
8
10
Name
V
STR
CS/FB
Latch/SS
Rt/Ct
GND
Out
V
CC
V
REF
Startup
Description
Current Sense and Feedback
Latch Protection and Soft-Start
Oscillator Timing
Ground
Gate Drive Output
IC Power Supply
Voltage Reference
© 2008 Fairchild Semiconductor Corporation
FAN7601B • Rev.1.0.3
www.fairchildsemi.com
3
FAN7601B — 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
operable above the recommended operating conditions and stressing the parts to these levels is not recommended. In
addition, extended exposure to stresses above the recommended operating conditions may affect device reliability. The
absolute maximum ratings are stress ratings only.
Symbol
V
CC
V
CS/FB
T
STG
T
J
I
O
V
STR
ESD
Supply Voltage
Input Voltage CS/FB
Storage Temperature
Parameter
Min.
-0.3
-55
-40
Max.
20
20.0
+150
+150
250
500
Unit
V
V
°C
°C
mA
V
V
Recommended Operating Junction Temperature
Output Current
V
STR
Input Voltage
Electrostatic Discharge
Capability
Human Body Model, JESD22-A114
Charged Device Model, JESD22-C101
2000
1500
Thermal Impedance
Symbol
θ
JA
Parameter
Thermal Resistance, Junction-to-Ambient
8-SOP
10-SSOP
Value
180
130
Unit
°C/W
© 2008 Fairchild Semiconductor Corporation
FAN7601B • Rev.1.0.3
www.fairchildsemi.com
4
FAN7601B — Green Current Mode PWM Controller
Electrical Characteristics
T
A
=-25°C~125°C, V
CC
=14V, R
T
=9.5kΩ, C
T
=2.2nF unless otherwise specified.
Symbol
Reference Section
V
REF
ΔV
REF1
ΔV
REF2
f
OSC
ST
V
V
OSC
V
CS/FB1
D
MAX
D
MIN
V
CS/FB2
V
CS/FB3
I
SS
V
SL
V
LATCH
V
OVP
V
tH
V
tL
I
OP
V
OL
V
OH
t
r
t
f
Parameter
Reference Output Voltage
Line Regulation
Load Regulation
Initial Accuracy
Voltage Stability
Amplitude
CS/FB Threshold Voltage1
Maximum Duty Cycle
Minimum Duty Cycle
CS/FB Threshold Voltage2
(2)
CS/FB Threshold Voltage3
(2)
Soft-Start Current
Soft-Start Limit Voltage
(3)
Latch Voltage
Over-Voltage Protection
Start Threshold Voltage
Minimum Operating Voltage
Operating Supply Current
Low Output Voltage
High Output Voltage
Rising Time
(2)
Falling Time
(2)
Conditions
I
O
=1mA
V
CC
=10V~18V
I
O
=1mA ~ 10mA
Min.
4.85
Typ.
5.00
10
20
Max.
5.15
20
30
110
1.5
Unit
V
mV
mV
kHz
%
V
Oscillator Section
90
V
CC
=10V~18V
V
pin4 peak-to-peak
0.9
T
A
=25°C
92
100
1.0
1.25
1.0
95
1.1
98
0
0.77
0.7
V
pin3
=GND
I
SS
=1μA
9
1.2
2.25
18
11
7
0.97
0.9
12
1.5
2.50
19
12
8
3
T
A
=25°C, I
O
=100mA
T
A
=25°C, I
O
=-100mA
T
A
=25°C, C
I
=1nF
T
A
=25°C, C
I
=1nF
11.5
2.0
12.0
45
35
1.17
1.1
15
1.8
2.75
20
13
9
4
2.5
14.0
150
150
PWM Section
V
%
%
V
V
μA
V
V
V
V
V
mA
V
V
ns
ns
Burst Mode Section
Soft-Start Section
Protection Section
UVLO Section
Total Current Section
Output Section
Startup Section
I
str
V
STR
Startup Current
V
STR
=30V, T
A
=25°C
0.5
1.0
1.5
mA
Notes:
2. These parameters, although guaranteed, are not 100% tested in production.
3. It is recommended to connect a 1MΩ resistor between the Latch/SS pin and GND to prevent abnormal operation of
the latch protection by noise coupling.
© 2008 Fairchild Semiconductor Corporation
FAN7601B • Rev.1.0.3
www.fairchildsemi.com
5
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