FAN6862W — Highly Integrated Green-Mode PWM Controller
September 2012
FAN6862W
Highly Integrated Green-Mode PWM Controller
Features
Low Standby Power: Under 0.1 W
Low Startup Current: 8 µA
Low Operating Current in Green Mode: 600 µA
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 (FAN6862WL) for OVP, OTP
Fixed PWM Frequency (65 KHz) with Frequency
Hopping
Feedback Open-Loop Protection: 60 ms Delay
GATE Output Maximum Voltage Clamp: 13.5V
Soft-Start Time: 5 ms
Soft Driving for EMI Improvement
Full Range Frequency Hopping
Internal OTP Sensor with Hysteresis
Gate Driving Capability: 400 mA
Description
A highly integrated PWM controller, FAN6862W
provides several features to enhance the performance
of flyback converters. To minimize standby power
consumption, a proprietary Green Mode 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. Green Mode enables power supplies to meet
international power conservation requirements.
The FAN6862W is designed for SMPS and integrates a
frequency-hopping function that helps to reduce EMI
emission of a power supply with minimum line filters. To
compensate the power limit variation over universal
input range, a bias current limit (V
LIMIT
) adaptively keeps
the power limit substantially constant. The gate output is
clamped at 13.5 V to protect the external MOSFET from
over-voltage damage.
Other protection functions include V
DD
Over-Voltage
Protection (OVP), and Over-Temperature Protection
(OTP). For OTP, 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. Protection types are shown in Table 1.
Table 1. Protection Type
Applications
General-purpose switched-mode power supplies and
flyback power converters, including:
Part Number
FAN6862W
FAN6862WL
FAN6862WR
OVP
Latch
Latch
A/R
OLP
A/R
Latch
A/R
OTP / OTP2
Latch
Latch
A/R
Power Adapters
Open-Frame SMPS
SMPS with Surge-Current Output, such as for
Printers, Scanners, Motor Drivers
Ordering Information
Part Number
FAN6862WTY
FAN6862WLTY
FAN6862WRTY
-40 to +105°C
6-Lead, SOT23, JEDEC MO-178 Variation AB, 1.6 mm Wide
Tape & Reel
Operating
Temperature
Range
Package
Packing
Method
© 2012 Fairchild Semiconductor Corporation
FAN6862W • Rev. 1.0.0
www.fairchildsemi.com
FAN6862W — Highly Integrated Green-Mode PWM Controller
Typical Application
Figure 1. Typical Application
Block Diagram
Figure 2. Block Diagram
© 2012 Fairchild Semiconductor Corporation
FAN6862W • Rev. 1.0.0
www.fairchildsemi.com
2
FAN6862W — Highly Integrated Green-Mode PWM Controller
Marking Information
Axx:
ABY: FAN6862WTY
ABZ: FAN6862WRTY
ACA: FAN6862WLTY
TT:
Wafer Lot Code
:
Year Code
_ _ _
:
Week Code
Figure 3. Top Mark
Pin Configuration
Figure 4. Pin Configuration
Pin Definitions
Pin #
1
2
Name
GND
FB
Function
Ground
Feedback
Ground
Description
The FB pin provides the output voltage regulation signal. It provides feedback to
the internal PWM comparator, so the PWM comparator can control the duty
cycle. This pin also provides over-current protection. IF V
FB
is higher than the
trigger level and persists at that level, the controller stops and restarts.
An external NTC thermistor is connected from this pin to the GND pin. The
impedance of the NTC decreases at high temperatures. If the voltage of the RT
pin drops below the threshold, PWM output is disabled.
3
RT
Temperature
Detection
4
5
6
This pin senses the voltage across a resistor. When the voltage reaches the
internal threshold, PWM output is disabled and this activates over-current
SENSE Current Sense
protection. This pin also provides current amplitude information for Current
Mode control.
VDD
GATE
Power Supply Power supply
Driver Output The totem-pole output driver for driving the power MOSFET
© 2012 Fairchild Semiconductor Corporation
FAN6862W • Rev. 1.0.0
www.fairchildsemi.com
3
FAN6862W — 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
Θ
JA
T
J
T
STG
T
L
ESD
Supply Voltage
Parameter
Input Voltage to FB, SENSE, and RT Pins
Thermal Resistance (Junction-to-Ambient)
Operating Junction Temperature
Storage Temperature Range
Lead Temperature, Wave Soldering, 10 Seconds
Human Body Model, JESD22-A114
Charge Device Model, JESD22-C101
Min.
-0.3
-40
-55
Max.
30
7.0
244
+125
+150
+260
5.5
2.0
Unit
V
V
°C/W
°C
°C
°C
kV
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
© 2012 Fairchild Semiconductor Corporation
FAN6862W • Rev. 1.0.0
www.fairchildsemi.com
4
FAN6862W — Highly Integrated Green-Mode PWM Controller
Electrical Characteristics
V
DD
= 15 V 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-OP1
I
DD-OP2
V
DD-OVP
t
D-VDDOVP
I
DD-LH
Parameter
Continuously Operating Voltage
Turn-On Threshold Voltage
Turn-Off Voltage
Threshold Voltage for Latch-Off Release
Startup Current
Operating Supply Current in PWM Operation
Operating Supply Current when V
FB
< V
FB-ZDC
V
DD
Over-Voltage Protection
V
DD
OVP Debounce Time
Latch-Off Holding Current
Condition
Min.
Typ.
Max.
20
Unit
V
V
V
V
15
6.5
FAN6862W,
FAN6862WL Only
V
DD-ON
– 0.16 V
V
DD
= 20 V,
V
FB
= 3 V Gate Open
V
DD
= 15 V,
V
FB
< V
FB-ZDC
FAN6862WL-Latch,
FAN6862WR-Auto
Restart
V
DD
= 5 V;
FAN6862W,
FAN6862WL Only
21.0
16
7.0
4
8
17
7.5
15
2
µA
mA
µA
600
22.2
50
70
80
23.5
V
µs
µA
Feedback Input Section
A
V
Z
FB
V
FB-OPEN
V
FB-OLP
t
D-OLP
Input-Voltage to Current-Sense Attenuation
Input Impedance
FB Pin Open Voltage
Threshold Voltage for Open-Loop Protection
Open-Loop Protection Delay
V
FB
> V
FB-OLP,
t
ON
> 2.5 µs,
T
A
= -40 to +105°C
FB > V
FB-OLP
,
t
ON
< 2.5 µs,
T
A
= -40 to +105°C
V
FB
>V
FB-OLP
,
T
A
= -40 to +105°C
5.2
4.3
54
1/4.0
1/3.5
17
5.4
4.6
60
5.6
4.9
66
1/3.0
V/V
kΩ
V
V
ms
t
D-SCP
t
ON-SCP
Secondary Short-Circuit Protection Delay
Short-Circuit Protection On-Time Detection
6
7
2.5
8
ms
µs
Current Sense Section
t
PD
t
LEB
V
LIMIT-H
V
LIMIT-L
Delay to Output
Leading-Edge Blanking Time
High Threshold Voltage for Current Limit
Low Threshold Voltage for Current Limit
Duty>55%
Duty = 0%
Startup Time
200
0.57
0.36
4.75
100
250
0.60
0.39
5.00
0.63
0.42
10.00
250
ns
ns
V
V
ms
t
SOFT-START
Period During Startup Time
Continued on the following page…
© 2012 Fairchild Semiconductor Corporation
FAN6862W • Rev. 1.0.0
www.fairchildsemi.com
5
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