FAN6862 — Highly Integrated Green-Mode PWM Controller
January 2010
FAN6862
Highly Integrated Green-Mode PWM Controller
Features
Low Startup Current: 8µA
Low Operating Current in Green Mode: 3mA
Peak-Current Mode Operation with Cycle-by-Cycle
Current Limiting
PWM Frequency Continuously Decreasing with
Burst Mode at Light Loads
V
DD
Over-Voltage Protection (OVP)
Constant Output Power Limit (Full AC Input Range)
Internal Latch Circuit for OVP, OTP
Fixed PWM Frequency (65KHz) with Frequency
Hopping
Feedback Open-Loop Protection with 56ms Delay
Soft Start Time: 4ms
400mA Driving Capability
Description
A highly integrated PWM controller, FAN6862 provides
several features to enhance the performance of flyback
converters. To minimize standby power consumption, a
proprietary green-mode function provides off-time
modulation to continuously decrease the switching
frequency under light-load conditions. Under zero-load
conditions, the power supply enters burst-mode, which
completely shuts off PWM output. Output restarts just
before the supply voltage drops below the UVLO lower
limit. This green-mode function enables power supplies
to meet international power conservation requirements.
The FAN6862 is designed for SMPS and integrates a
frequency-hopping function that helps reduce EMI
emission of a power supply with minimum line filters.
The built-in synchronized slope compensation is
proprietary sawtooth compensation for constant output
power limit over universal AC input range. The gate
output is clamped at 18V to protect the external
MOSFET from over-voltage damage.
Other protection functions include V
DD
over-voltage
protection and over-temperature protection. For over-
temperature protection, an external NTC thermistor can
be applied to sense the ambient temperature. When
V
DD
OVP or OTP is activated, an internal latch circuit
latches off the controller.
Applications
General-purpose switch-mode power supplies and
flyback power converters, including:
Power Adapters
Open-Frame SMPS
SMPS with Surge-Current Output, such as for
Printers, Scanners, and Motor Drivers
Part Number
FAN6862TY
FAN6862NY
OVP
Latch
Latch
OTP
Latch
Latch
OLP
Auto Restart
Auto Restart
Ordering Information
Part Number
FAN6862TY
FAN6862NY
Operating
Temperature Range
-40 to +105°C
-40 to +105°C
Eco Status
Green
Green
Package
6-Pin SSOT-6
8-Pin Dual In-Line Package (DIP)
Packing
Method
Tape & Reel
Tube
For Fairchild’s definition of Eco Status, please visit:
http://www.fairchildsemi.com/company/green/rohs_green.html.
© 2009 Fairchild Semiconductor Corporation
FAN6862 • Rev. 1.0.2
www.fairchildsemi.com
FAN6862 — Highly Integrated Green-Mode PWM Controller
Typical Application
Figure 1. Typical Application
Block Diagram
Figure 2. Block Diagram
© 2009 Fairchild Semiconductor Corporation
FAN6862 • Rev. 1.0.2
www.fairchildsemi.com
2
FAN6862 — Highly Integrated Green-Mode PWM Controller
Marking Information
ABx:
TT:
:
_ _ _
:
ABD: FAN6862TY
Wafer Lot Code
Year Code
Week Code
F
– Fairchild Logo
Z
– Plant Code
X
– 1-Digit Year Code
Y
– 1-Digit Week Code
TT
– 2-Digit Die Run Code
T
– Package Type (N:DIP)
P
– Y: Green Package
M
– Manufacture Flow Code
Figure 3. Top Mark
Pin Configuration
Figure 4. SSOT-6
Figure 5. DIP-8
Pin Definitions
Pin #
DIP8
8
Pin #
SSOT-6
1
Name
GND
Ground.
Description
7
2
FB
Feedback.
The FB pin provides the output voltage regulation signal. It
provides feedback to the internal PWM comparator, so that the PWM
comparator can control the duty cycle. This pin also provide for OLP: if V
FB
is
larger than the trigger level and delays for a long time, the controller stops
and restarts.
No Connect Pin
Temperature Detection.
An external NTC thermistor is connected from this
pin to GND for over-temperature protection. The impedance of the NTC
decreases at high temperatures. Once the voltage of the RT pin drops below
a threshold,
PWM output is disabled.
Current Sense.
This pin senses the voltage across a resistor. When the
voltage reaches the internal threshold, PWM output is disabled. This activates
over-current protection. This pin also provides current amplitude information
for current-mode control.
No Connect Pin
Power Supply.
Driver Output.
The totem-pole output driver for driving the power MOSFET.
6
NC
5
3
RT
4
3
2
1
4
SENSE
NC
5
6
VDD
GATE
© 2009 Fairchild Semiconductor Corporation
FAN6862 • Rev. 1.0.2
www.fairchildsemi.com
3
FAN6862 — Highly Integrated Green-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. All voltage values, except differential voltages, are
given with respect to GND pin.
Symbol
V
DD
V
L
P
D
Θ
JC
T
J
T
STG
T
L
ESD
Supply Voltage
Parameter
Input Voltage to FB, SENSE, RT Pin
Power Dissipation at T
A
<50°C
Thermal Resistance (Junction-to-Case)
Operating Junction Temperature
Storage Temperature Range
Lead Temperature, Wave Soldering, 10 Seconds
Human Body Model, JESD22-A114
Charge Device Model, JESD22-C101
SSOT-6
DIP-8
SSOT-6
DIP-8
Min.
-0.3
Max.
30
7.0
300
800
115
67
Unit
V
V
mW
°C/W
°C
°C
°C
kV
-40
-55
+150
+150
+260
3.00
1.25
Recommended Operating Conditions
The Recommended Operating Conditions table defines the conditions for actual device operation. Recommended
operating conditions are specified to ensure optimal performance to the datasheet specifications. Fairchild does not
recommend exceeding them or designing to Absolute Maximum Ratings.
Symbol
T
A
Parameter
Operating Ambient Temperature
Min.
-40
Max.
+105
Unit
°C
© 2009 Fairchild Semiconductor Corporation
FAN6862 • Rev. 1.0.2
www.fairchildsemi.com
4
FAN6862 — Highly Integrated Green-Mode PWM Controller
Electrical Characteristics
V
DD
= 15V and T
A
= 25°C unless otherwise noted.
Symbol
V
DD
Section
V
DD-OP
V
DD-ON
V
DD-OFF
V
DD-LH
I
DD-ST
I
DD-OP
I
DD-BM
V
DD-OVP
t
D-VDDOVP
I
DD-LH
A
V
Z
FB
V
FB-OPEN
V
FB-OLP
t
D-OLP
t
PD
t
LEB
V
STHFL
V
STHVA
V
SLOPE
t
SOFT-START
Parameter
Continuously Operating Voltage
Turn-on Threshold Voltage
Turn-off Voltage
Threshold voltage for Latch-Off release
Startup Current
Normal Operating Supply Current
Green-Mode Operating Supply Current
V
DD
Over-Voltage Protection
V
DD
OVP Debounce Time
Latch-Off Holding Current
Input-Voltage to Current-Sense Attenuation
Input Impedance
FB Pin Open Voltage
Threshold Voltage for Open-Loop
Protection
Open-Loop Protection Delay Time
Delay to Output
Leading-Edge Blanking Time
Flat Threshold Voltage for Current Limit
Valley Threshold Voltage for Current Limit
Slope Compensation
Period During Startup time
Center
Frequency
Test Condition
Min.
Typ.
Max.
24
Unit
V
V
V
V
μA
mA
mA
V
μs
μA
V/V
kΩ
V
V
ms
ns
ns
V
V
V
ms
15
7.5
3
V
DD-ON
–0.16V
C
L
=1nF
GATE open, V
FB
=V
FB-G
24
V
DD
=5V
1/4.0
5.0
4.3
53
16
8.5
4
8
3
25
30
40
1/3.5
5.5
5.2
4.6
56
100
17
9.5
5
30
4
2.5
26
50
65
1/3.0
5.4
4.9
60
250
Feedback Input Section
Current Sense Section
270
Duty>51%
Duty=0%
Duty=DCY
MAX
360
0.5
0.44
0.273
4
Oscillator Section
V
FB
>V
FB-N
V
FB
≥V
FB-N
V
FB
=V
FB-G
V
FB
≥V
FB-N
V
FB
=V
FB-G
62
65
±4.2
±2.9
4.4
11.5
22.5
2.2
2.1
1.7
V
DD
=11.5V to 20V
T
A
= -40 to +105°C
0
0.02
2.00
2
ms
ms
kHz
V
V
V
%
%
68
kHz
f
OSC
Normal PWM Frequency Hopping Range
Hopping Range
Hopping Period 1
Hopping Period 3
Green Mode Minimum Frequency
FB Threshold Voltage For Frequency
Reduction
FB Voltage at f
OSC-G
FB Threshold Voltage for Zero Duty
Frequency Variation vs. V
DD
Deviation
Frequency Variation vs. Temperature
Deviation
t
hop-1
t
hop-3
f
OSC-G
V
FB-N
V
FB-G
V
FB-ZDC
f
DV
f
DT
Continued on the following page…
© 2009 Fairchild Semiconductor Corporation
FAN6862 • Rev. 1.0.2
www.fairchildsemi.com
5
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