FAIRCHILD FAN400CNY

FAN400C — Low-Power, Green-Mode, PWM Flyback Power
Controller without Secondary Feedback (CC)
Features
Description
ƒ Linearly Decreasing PWM Frequency
ƒ Green Mode Under Light-Load and Zero-Load
This highly integrated PWM controller provides several
features to enhance the performance of low-power
flyback converters. To minimize standby power
consumption, a proprietary green-mode function
provides off-time modulation to linearly decrease the
switching frequency under light-load and zero-load
conditions. This green mode enables the power supply
to meet international power conservation requirements.
Another advantage of the FAN400C is that the typical
startup current is only 8μA, while the typical operating
current can be as low as 3.6mA. A large startup
resistance can be used to achieve higher power
conversion efficiency.
Conditions
ƒ Constant Current (CC) without Secondary-Feedback
Circuitry
ƒ Low Startup Current: 8μA
ƒ Low Operating Current: 3.6mA
ƒ Leading-Edge Blanking
ƒ Constant Power Limit
ƒ Universal AC Input Range
ƒ Synchronized Slope Compensation
ƒ 140°C OTP Sensor with Hysteresis
ƒ VDD Over-Voltage Protection (Auto Restart)
ƒ Cycle-by-Cycle Current Limiting
ƒ Under-Voltage Lockout (UVLO)
ƒ Fixed PWM Frequency with Hopping
ƒ Gate Output Maximum Voltage Clamped at 17V
ƒ Small SSOT-6 Package
Applications
General-purpose, switching-mode, power supplies and
flyback power converters, such as:
ƒ Battery Chargers for Cellular Phones, Cordless
Phones, PDAs, Digital Cameras, Power Tools
ƒ Power Adapters for Ink Jet Printers, Video Game
Consoles, Portable Audio Players
ƒ Open-Frame SMPS for TV/DVD Standby and
Auxiliary Supplies, Home Appliances, Consumer
Electronics
ƒ Replacement for Linear Transformers and RCC SMPS
ƒ PC 5V Standby Power
FAN400C integrates a frequency-hopping function
internally to reduce EMI emissions with minimum line
filters. Built-in synchronized slope compensation
maintains the stability of peak current-mode control.
Proprietary internal compensation ensures constant
output power limiting over a universal range of AC input
voltages, from 90VAC to 264VAC.
The FAN400C provides many protection functions.
Pulse-by-pulse current limiting ensures constant output
current, even if a short circuit occurs. The internal
protection circuit disables PWM output if VDD exceeds
24.5V. The gate output is clamped at 17V to protect the
power MOS from over-voltage damage. The built-in
over-temperature protection (OTP) function shuts down
the controller at 140°C with a 30°C hysteresis.
The FAN400C is designed to provide a low-cost total
solution for flyback converters. It is available in a smallfootprint, 6-pin, SSOT-6 package.
Related Resources
ƒ
AN-6072 — Low-Power, Green-Mode, PWM Flyback
Power Controller without Secondary Feedback
Ordering Information
Part Number
Packing Method
Operating Temperature Range
Package
FAN400CTY
-40°C to +105°C
SSOT-6
Green
Tape & Reel
FAN400CNY
-40°C to +105°C
DIP-8
Green
Tube
Eco Status
For Fairchild’s definition of “green” please visit: http://www.fairchildsemi.com/company/green/rohs_green.html.
© 2008 Fairchild Semiconductor Corporation
FAN400C • Rev. 1.0.1
www.fairchildsemi.com
FAN400C — Low-Power, Green-Mode, PWM Flyback Power Controller without Secondary Feedback (CC)
September 2008
Figure 1.
Typical Application
Internal Block Diagram
Figure 2.
© 2008 Fairchild Semiconductor Corporation
FAN400C • Rev. 1.0.1
Functional Block Diagram
FAN400C — Low-Power, Green-Mode, PWM Flyback Power Controller without Secondary Feedback (CC)
Application Diagram
www.fairchildsemi.com
2
XXX: AAU=FAN400C
TT : Die run code
. . . : Year code
- - - : Week code
1’st line
Z: Assembly plant code
X: Year code
Y: Week code
TT: Die run code
3’rd line
T: N=DIP
P: Z=Lead free + RoHS compatible
Y=Green package
M: Manufacture flow code
Figure 3.
Top Mark
Pin Configurations
GND
FB
VDD
NC
Figure 4.
GND
GATE
GATE
SENSE
VDD
FB
NC
NC
SENSE
SSOT-6 Pin Configuration
Figure 5.
NC
DIP-8 Pin Configuration
Pin Definitions
DIP
Pin #
SSOT
Pin #
Name
Description
1
6
GATE
The totem-pole output driver to drive the power MOSFET
2
5
VDD
Power supply
NC
No connection
3
4
4
5
SENSE
Current-sense detects the voltage across a sensed resistor. To provide overcurrent protection, PWM output is disabled if the voltage exceeds an internal
threshold. This pin also provides current information for current-mode control.
NC
No connection
6
3
NC
No connection
7
2
FB
The FB pin provides feedback information to the internal PWM comparator. This
feedback is used to control the duty cycle.
8
1
GND
© 2008 Fairchild Semiconductor Corporation
FAN400C • Rev. 1.0.1
FAN400C — Low-Power, Green-Mode, PWM Flyback Power Controller without Secondary Feedback (CC)
Marking Information
Ground
www.fairchildsemi.com
3
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
Parameter
Min.
(1,2)
Max.
Unit
30
V
VDD
DC Supply Voltage
VFB
Input Voltage to FB Pin
-0.3
7.0
V
Input Voltage to Sense Pin
-0.3
7.0
V
+150
°C
SOT
263.3
°C/W
DIP
135.7
°C/W
+150
°C
VSENSE
TJ
Operating Junction Temperature
ΘJA
Thermal Resistance
(Junction-to-Air)
TSTG
Storage Temperature Range
TL
ESD
-55
+260
°C
Human Body Model
JEDEC: JESD22-A114
4
kV
Machine Model,
JEDEC: JESD22-A115
200
V
Lead Temperature (Wave Soldering or IR, 10 Seconds)
Electrostatic Discharge Capability
Notes:
1. All voltage values, except differential voltages, are given with respect to GND pin.
2. Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device.
© 2008 Fairchild Semiconductor Corporation
FAN400C • Rev. 1.0.1
FAN400C — Low-Power, Green-Mode, PWM Flyback Power Controller without Secondary Feedback (CC)
Absolute Maximum Ratings
www.fairchildsemi.com
4
Unless otherwise noted, VDD=15V and TA=25°C.
Symbol
Parameter
Conditions
Min.
Typ.
Max.
Units
VDD Section
VDD-OP
Continuously Operation Voltage
23.5
V
VDD-ON
Turn-On Threshold Voltage
16
17
18
V
VDD-OFF
Turn-Off Threshold Voltage
7.5
8.0
8.5
V
IDD-ST
Startup Current
IDD-OP
Operating Supply Current
VDD-G OFF
VDD=VDD-ON – 0.1V
CL=1nF
VDD Low-threshold Voltage to Exit Green-off
Mode
VDD-OVP
VDD Over-Voltage Protection
tD-VDDOVP
VDD Over-Voltage Protection Debounce
Time
8
20
μA
3.6
4.6
mA
V
VDD-OFF+1.2
23.5
24.5
25.5
V
70
135
200
μs
1.5/5
2.0/5
2.5/5
V/V
Feedback Input Section
AV
Input-Voltage to Current-Sense Attenuation
ZFB
Input Impedance
VFB-OPEN
IFB=0.1mA to 0.2mA
Open-Loop Voltage
4.6
kΩ
4.5
V
Current-Sense Section
tPD
VSTHVA
VSTHFL
tLEB
Propagation Delay
100
Current Limit Valley Threshold Voltage
Current Limit Flat Threshold Voltage
ns
VDD=18V
0.81
V
VDD=15V
0.73
V
VDD=10V
0.58
V
VDD=18V
1.10
V
VDD=15V
1.01
V
VDD=10V
0.81
V
Leading-Edge Blanking Time
250
Figure 6.
© 2008 Fairchild Semiconductor Corporation
FAN400C • Rev. 1.0.1
150
310
370
ns
FAN400C — Low-Power, Green-Mode, PWM Flyback Power Controller without Secondary Feedback (CC)
Electrical Characteristics
Saw Limit
www.fairchildsemi.com
5
Unless otherwise noted, VDD=15V and TA=25°C.
Symbol
Parameter
Conditions
Min.
Typ.
Max.
Units
Oscillator Section
fOSC
Frequency
tHOP
Hopping Period
Center Frequency
Hopping Range
60
65
70
±4.0
±4.6
±5.2
4
fOSC-G
Green Mode Frequency
14.5
2.3
VFB-N
Green Mode Entry FB Voltage
VFB-G
Green Mode Ending FB Voltage
VFB-Z
Zero Duty Cycle FB Voltage
SG
Green Mode Modulation Slope
40
fDV
Frequency Variation vs. VDD Deviation
VDD=10 to 22V
fDT
Frequency Variation vs. Temperature
Deviation
TA=-20 to 85°C
kHz
ms
17.0
19.5
2.6
2.9
KHz
V
VFB-N -0.75
V
1.45
V
70
1.5
100
Hz/mV
2
%
5.0
%
78
%
1.5
V
Output Section
DCYMAX
Maximum Duty Cycle
VGATE-L
GATE Low Voltage
IO=10mA
68
VGATE-H
GATE High Voltage
IO=-10mA
73
8
V
tr
GATE Rising Time
CL=1nF
150
200
250
ns
tf
GATE Falling Time
CL=1nF
70
90
110
ns
GATE Output Clamping Voltage
VDD=20V
16
17
18
V
VGATECLAMP
Over-Temperature Protection (OTP)
TOTP
TOTPRESTART
Protection Junction Temperature
+140
°C
Restart Junction Temperature
+110
°C
© 2008 Fairchild Semiconductor Corporation
FAN400C • Rev. 1.0.1
FAN400C — Low-Power, Green-Mode, PWM Flyback Power Controller without Secondary Feedback (CC)
Electrical Characteristics (Continued)
www.fairchildsemi.com
6
8.6
17.2
8.4
V DD-OFF (V)
V DD-ON (V)
17.4
17
16.8
16.6
8.2
8
7.8
16.4
7.6
-40
-30 -20
-10
0
10
20
30
40
50
60
70
80
90
100
-40
-30 -20
-10
0
T emperature (℃ )
Figure 7.
10
20
30
40
50
60
70
80
90
100
T emperature (℃ )
Turn-on Threshold Voltage (VDD-ON)
vs. Temperature
Figure 8.
Turn-off Threshold Voltage (VDD-OFF)
vs. Temperature
3.4
12
11
3.2
IDD-OP (mA)
IDD-ST (μA)
10
9
8
7
3
2.8
2.6
6
2.4
5
4
2.2
-40
-30
-20
-10
0
10
20
30
40
50
60
70
80
90
-40
100
-30 -20
-10
0
T emperature (℃ )
Figure 9.
20
30
40
50
60
70
80
90
100
T emperature (℃ )
Startup Current (IDD-ST) vs.
Temperature
Figure 10.
Operating Supply Current (IDD-OP)
vs. Temperature
75
68
67
74
66
DCY MAX (%)
fOSC (KHz)
10
65
64
73
72
71
63
62
70
-40
-30
-20
-10
0
10
20
30
40
50
60
70
80
90
-40
100
-30
-20
-10
T emperature (℃ )
Figure 11.
10
20
30
40
50
60
70
80
90
100
T emperature (℃ )
Center Frequency (fOSC)
vs. Temperature
© 2008 Fairchild Semiconductor Corporation
FAN400C • Rev. 1.0.1
0
Figure 12.
FAN400C — Low-Power, Green-Mode, PWM Flyback Power Controller without Secondary Feedback (CC)
Typical Performance Characteristics
Maximum Duty Cycle (DCYMAX)
vs. Temperature
www.fairchildsemi.com
7
2.2
2.8
2
V FB-G (V)
V FB-N (V)
3
2.6
2.4
2.2
1.8
1.6
1.4
2
1.2
-40
-30 -20
-10
0
10
20
30
40
50
60
70
80
90
100
-40
-30 -20
-10
0
T emperature (℃ )
Figure 13.
20
30
40
50
60
70
80
90
100
T emperature (℃ )
Green Mode Entry FB Voltage
(VFB-N) vs. Temperature
Figure 14.
360
Green Mode Ending FB Voltage
(VFB-G) vs. Temperature
3.4
3.2
IDD-OP (mA)
340
tLEB (ns)
10
320
300
280
3
2.8
2.6
2.4
2.2
260
-40
-30
-20
-10
0
10
20
30
40
50
60
70
80
90
12
100
13
14
15
Figure 15.
Leading-Edge Blanking Time (tLEB)
vs. Temperature
© 2008 Fairchild Semiconductor Corporation
FAN400C • Rev. 1.0.1
16
17
18
19
20
21
22
23
V DD (V)
Temperature (℃ )
Figure 16.
Operating Supply Current
vs. VDD Voltage
24
FAN400C — Low-Power, Green-Mode, PWM Flyback Power Controller without Secondary Feedback (CC)
Typical Performance Characteristics
www.fairchildsemi.com
8
FAN400C devices integrate many useful functions for
low-power switch-mode power supplies. The following
descriptions highlight the key features of the FAN400C.
Oscillator Operation
Startup Current
Leading-Edge Blanking (LEB)
The oscillation frequency is fixed at 65KHz.
Each time the power MOSFET is switched on, a turn-on
spike occurs at the sense-resistor. To avoid premature
termination of the switching pulse, a 310ns leadingedge blanking time is built in. Conventional RC filtering
is not necessary. During this blanking period, the
current-limit comparator is disabled and cannot switch
off the gate drive.
The required startup current is only 8mA, which allows a
high-resistance, low-wattage startup resistor to supply
the controller’s startup power. A 1.5MΩ/0.25W startup
resistor can be used over a wide input range (100V240VAC) with very little power loss.
Operating Current
Constant Output Power Limit
The operating current is normally 3.6mA, which results
in higher efficiency and reduces the required VDD holdup capacitance. A 10μF/25V VDD hold-up capacitor can
be used over a wide input range (100V-240VAC) with
very little power loss.
When the SENSE voltage across the sense resistor RS
reaches the threshold voltage (around 1.0V), the output
GATE drive is turned off following a small propagation
delay, tPD. This propagation delay introduces an
additional current proportional to tPD•VIN/LP. The
propagation delay is nearly constant regardless of the
input line voltage VIN. Higher input line voltages result in
larger additional currents. Under high input-line
voltages, the output power limit is higher than under low
input-line voltages. Over a wide range of AC input
voltages, the variation can be significant. To
compensate for this, the threshold voltage is adjusted
by adding a positive ramp (Vlimit_ramp). This ramp signal
can vary from 0.73V to 1.01V and flattens out at 1.01V.
A smaller threshold voltage forces the output GATE
drive to terminate earlier, reducing total PWM turn-on
time and making the output power equal to that of the
low-line input. This proprietary internal compensation
feature ensures a constant output power limit over a
wide range of AC input voltages (90VAC to 264VAC).
Green-Mode Operation
The proprietary green-mode function provides off-time
modulation to linearly decrease the switching frequency
under light-load and zero-load conditions. The on-time
is limited to provide better protection against brownouts
and other abnormal conditions. Power supplies using
the FAN400C can meet international restrictions
regarding standby power-consumption.
Current (CC) without Feedback
The FAN400C can provide over-current protection
without requiring secondary-side feedback signals. For
improved CV and CC accuracy, the transformer leakage
inductance should be reduced as much as possible.
Over-Temperature Protection (OTP)
Under-Voltage Lockout (UVLO)
The FAN400C has a built-in temperature-sensing circuit
to shut down PWM output once the junction
temperature exceeds 140°C. While PWM output is shut
down, the VDD voltage gradually drops to the UVLO
voltage. Some of the internal circuits are shut down and
VDD gradually starts increasing again. When VDD
reaches 17V, all the internal circuits, including the
temperature-sensing circuit, operate normally. If the
junction temperature is still higher than 140°C, the
PWM controller shuts down immediately. This situation
continues until the temperature drops below 110°C. The
PWM output is then turned back on. The temperature
hysteresis window for the OTP circuit is 30°C.
The turn-on/turn-off thresholds are fixed internally at
17V and 8V. To enable the FAN400C during startup,
the hold-up capacitor must first be charged to 17V
through the startup resistor. The hold-up capacitor
continues to supply VDD before energy can be delivered
from the auxiliary winding of the main transformer. VDD
must not drop below 8V during this startup process.
This UVLO hysteresis window ensures that the hold-up
capacitor can adequately supply VDD during startup.
Gate Output
The BiCMOS output stage is a fast totem-pole gate
driver. Cross-conduction is avoided to minimize heat
dissipation, increase efficiency, and enhance reliability.
The output driver is clamped by an internal 17V Zener
diode to protect the power MOSFET transistors against
any harmful over-voltage gate signals.
VDD Over-Voltage Clamping
VDD over-voltage clamping prevents damage from overvoltage conditions. When VDD exceeds 24.5V, PWM
output is shut down. Over-voltage conditions may be
caused by an open photo-coupler loop or a short circuit
in the output.
© 2008 Fairchild Semiconductor Corporation
FAN400C • Rev. 1.0.1
FAN400C — Low-Power, Green-Mode, PWM Flyback Power Controller without Secondary Feedback (CC)
Operation Description
www.fairchildsemi.com
9
Slope Compensation
Noise Immunity
The sensed voltage across the current-sense resistor is
used for current-mode control and pulse-by-pulse
current limiting. The built-in slope compensation
improves power supply stability. Furthermore, it
prevents sub-harmonic oscillations that normally would
occur because of peak-current mode control. A
positively sloped, synchronized ramp is activated with
every switching cycle. The slope of the ramp is:
0.33 × Duty
(1)
Duty (max.)
Noise from the current-sense or the control signal may
cause significant pulse-width jitter, particularly in
continuous-conduction mode. Slope compensation
helps alleviate this problem. Good placement and
layout practices should be followed. Avoid long PCB
traces and component leads. Compensation and filter
components should be located near the FAN400C.
Increasing the power-MOS gate resistance is advised.
© 2008 Fairchild Semiconductor Corporation
FAN400C • Rev. 1.0.1
FAN400C — Low-Power, Green-Mode, PWM Flyback Power Controller without Secondary Feedback (CC)
Operation Description (Continued)
www.fairchildsemi.com
10
Figure 17.
Reference Circuit
BOM
Reference
Component
Reference
Component
BD1
BD DI106 1A/600V
L2
Inductor 10μH 6mm
CY1 (Option)
YC 2.2nF/250V (Y1)
Q1
MOSFET 1A/600V
C1
EC 4.7μF/400V 105°C
R1,R2
R 750kΩ/1206
C2
EC 4.7μF/400V 105°C
R3,R4
R 47kΩ/1206
C3
CC 1nF/1kV
R5
R 47Ω/1206
C4
EC 10μF/50V
R6
R 4.7Ω/0.5W
C6
CC 4.7nF/0805
R7
R 100Ω/0805
C7 (Option)
CC 1nF/100V 1206
R8
R 10Ω/1206
C8
EC 470μF/10V 105°C
R10
R 10Ω/1206
C9
EC 470μF/10V 105°C
R11
R 100Ω/ 1/8W
C10
CC 2.2nF/0805
R12
R 33kΩ/0805
D1
Diode FRI07
R13
R 33kΩ/ 1/8W
D2
Diode FR102
R14
R 4.7kΩ/0805
D4
Diode SB360
T1
Transformer EE-16
D5 (Option)
ZD 6.8V/0.5W
U1
IC FAN400C (Green PWM IC)
F1
R 1Ω/0.5W
U2
IC PC817
L1
Inductor 20mH 6*8mm
U3
IC TL431
© 2008 Fairchild Semiconductor Corporation
FAN400C • Rev. 1.0.1
FAN400C — Low-Power, Green-Mode, PWM Flyback Power Controller without Secondary Feedback (CC)
Applications Information
www.fairchildsemi.com
11
9.83
9.00
6.67
6.096
8.255
7.61
3.683
3.20
5.08 MAX
7.62
0.33 MIN
3.60
3.00
(0.56)
2.54
0.56
0.355
0.356
0.20
1.65
1.27
9.957
7.87
7.62
NOTES: UNLESS OTHERWISE SPECIFIED
A) THIS PACKAGE CONFORMS TO
JEDEC MS-001 VARIATION BA
B) ALL DIMENSIONS ARE IN MILLIMETERS.
C) DIMENSIONS ARE EXCLUSIVE OF BURRS,
MOLD FLASH, AND TIE BAR EXTRUSIONS.
D) DIMENSIONS AND TOLERANCES PER
ASME Y14.5M-1994
E) DRAWING FILENAME AND REVSION: MKT-N08FREV2.
Figure 18.
8-Pin, DIP-8 Package
Package drawings are provided as a service to customers considering Fairchild components. Drawings may change in any manner
without notice. Please note the revision and/or date on the drawing and contact a Fairchild Semiconductor representative to verify
or obtain the most recent revision. Package specifications do not expand the terms of Fairchild’s worldwide terms and conditions, specifically
the warranty therein, which covers Fairchild products.
FAN400C — Low-Power, Green-Mode, PWM Flyback Power Controller without Secondary Feedback (CC)
Physical Dimensions
Always visit Fairchild Semiconductor’s online packaging area for the most recent package drawings:
http://www.fairchildsemi.com/packaging/.
© 2008 Fairchild Semiconductor Corporation
FAN400C • Rev. 1.0.1
www.fairchildsemi.com
12
Figure 19. 6-Pin SSOT-6 Package
Package drawings are provided as a service to customers considering Fairchild components. Drawings may change in any manner
without notice. Please note the revision and/or date on the drawing and contact a Fairchild Semiconductor representative to verify
or obtain the most recent revision. Package specifications do not expand the terms of Fairchild’s worldwide terms and conditions, specifically
the warranty therein, which covers Fairchild products.
FAN400C — Low-Power, Green-Mode, PWM Flyback Power Controller without Secondary Feedback (CC)
Physical Dimensions (Continued)
Always visit Fairchild Semiconductor’s online packaging area for the most recent package drawings:
http://www.fairchildsemi.com/packaging/.
© 2008 Fairchild Semiconductor Corporation
FAN400C • Rev. 1.0.1
www.fairchildsemi.com
13
FAN400C — Low-Power, Green-Mode, PWM Flyback Power Controller without Secondary Feedback (CC)
14
www.fairchildsemi.com
© 2008 Fairchild Semiconductor Corporation
FAN400C • Rev. 1.0.1