Product Specification
Highly Integrated Green-Mode PWM Controller
SG5841/J
DESCRIPTION
The highly integrated SG5841/J series of PWM
controllers 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 at
light-load conditions. This green-mode function enables
the power supply to meet international power
conservation requirements. To further reduce power
consumption, SG5841/J is manufactured using the
BiCMOS process. This allows a low start-up current,
around 14µA, and an operating current of only 4mA. As a
result, a large start-up resistance can be used.
The SG5841/J built-in synchronized slope compensation
achieves stable peak-current-mode control. The
proprietary internal sawtooth power-limiter ensures
constant output power limit over a wide range of AC input
voltages, from 90VAC to 264VAC.
SG5841/J provides many protection functions. In addition
to cycle-by-cycle current limiting, the internal open-loop
protection circuit ensures safety should an open-loop or
output-short-circuit failure occur. PWM output is disabled
until V
DD
drops below the UVLO lower limit, then the
controller starts again. An external NTC thermistor can be
applied for over-temperature protection.
SG5841/J is available in an 8-pin DIP or SOP package.
FEATURES
Green-Mode PWM Controller
Low Start-Up Current (14µA)
Low Operating Current (4mA)
Programmable PWM Frequency with Hopping
Peak-Current-Mode Control
Cycle-by-Cycle Current Limiting
Synchronized Slope Compensation
Leading-Edge Blanking
Constant Output Power Limit
Totem Pole Output with Soft Driving
V
DD
Over-Voltage Clamping
Programmable Over-Temperature Protection (OTP)
Internal Open-Loop Protection
V
DD
Under-Voltage Lockout (UVLO)
GATE Output Maximum Voltage Clamp (18V)
APPLICATIONS
General-purpose switch-mode power
flyback power converters, including:
Power Adapters
Open-Frame SMPS
supplies
and
TYPICAL APPLICATION
SG5841/J
© System General Corp.
Version 1.3.1 (IAO33.0017.B6)
-1-
www.sg.com.tw • www.fairchildsemi.com
September 20, 2007
Product Specification
Highly Integrated Green-Mode PWM Controller
SG5841/J
PIN CONFIGURATION
GND
FB
VIN
RI
GATE
VDD
SENSE
RT
MARKING DIAGRAMS
H:
J = with Frequency Hopping
Null = without Frequency
Hopping
T:
D = DIP, S = SOP
P:
Z = Lead Free
Null=regular package
XXXXXXXX:
Wafer Lot
Y:
Year;
WW:
Week
V:
Assembly Location
SG5841HTP
XXXXXXXXYWWV
ORDERING INFORMATION
Part Number
SG5841JSZ
SG5841JDZ
SG5841SZ
SG5841DZ
Frequency Hopping
Yes
Yes
No
No
Pb-Free
Package
8-Pin SOP
8-Pin DIP
8-Pin SOP
8-Pin DIP
PIN DESCRIPTIONS
Pin No.
1
Symbol
GND
Function
Ground
Description
Ground.
The signal from the external compensation circuit is fed into this pin. The PWM duty cycle is
determined in response to the signal from this pin and the current-sense signal from Pin 6. If FB
voltage exceeds the threshold, the internal protection circuit disables PWM output after a
predetermined delay time.
For start-up, this pin is pulled high to the rectified line input via a resistor. Since the start-up
current requirement of the SG5841/J is very small, a large start-up resistance can be used to
minimize power loss.
A resistor connected from the RI pin to GND pin provides the SG5841/J with a constant current
source. This determines the center PWM frequency. Increasing the resistance reduces PWM
frequency. Using a 26KΩ resistor results in a 65KHz center PWM frequency.
For over-temperature protection. An external NTC thermistor is connected from this pin to the
GND pin. The impedance of the NTC decreases at high temperatures. Once the voltage of the
RT pin drops below a fixed limit, PWM output is disabled.
Current sense. The sensed voltage is used for peak-current-mode control and cycle-by-cycle
current limiting.
Power supply. If V
DD
exceeds a threshold, the internal protection circuit disables PWM output.
The totem-pole output driver for the power MOSFET, which is internally clamped below 18V.
2
FB
Feedback
3
VIN
Start-Up Input
4
RI
Reference
Setting
Temperature
Detection
Current Sense
Power Supply
Driver Output
5
RT
6
7
8
SENSE
VDD
GATE
© System General Corp.
Version 1.3.1 (IAO33.0017.B6)
-2-
www.sg.com.tw • www.fairchildsemi.com
September 20, 2007
Product Specification
Highly Integrated Green-Mode PWM Controller
SG5841/J
BLOCK DIAGRAM
5841J only
© System General Corp.
Version 1.3.1 (IAO33.0017.B6)
-3-
www.sg.com.tw • www.fairchildsemi.com
September 20, 2007
Product Specification
Highly Integrated Green-Mode PWM Controller
SG5841/J
ABSOLUTE MAXIMUM RATINGS
Symbol Parameter
V
VDD
V
VIN
V
FB
V
SENSE
V
RT
V
RI
P
D
R
Θ
JA
R
Θ
JC
T
J
T
STG
T
L
V
ESD,HBM
V
ESD,MM
Supply Voltage
Input Terminal
Input Voltage to FB Pin
Input Voltage to SENSE Pin
Input Voltage to RT Pin
Input Voltage to RI Pin
Power Dissipation (T
A
< 50°C )
Thermal Resistance (Junction-to-Air)
Thermal Resistance (Junction-to-Case)
Operating Junction Temperature
Storage Temperature Range
Lead Temperature (Wave Soldering or Infrared, 10 Seconds)
Electrostatic Discharge Capability, Human Body Model
Electrostatic Discharge Capability, Machine Model
Value
30
30
-0.3 to 7.0
-0.3 to 7.0
-0.3 to 7.0
-0.3 to 7.0
DIP
SOP
DIP
SOP
DIP
SOP
800.0
400.0
82.5
141.0
59.7
80.8
Unit
V
V
V
V
V
V
mW
°C/W
°C/W
°C
°C
°C
KV
V
-40 to +125
-55 to +150
260
3.0
250
* All voltage values, except differential voltages, are given with respect to GND pin.
* Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device.
RECOMMENDED OPERATING CONDITIONS
Symbol
T
A
Parameter
Operating Ambient Temperature
Value
-20 to +85
Unit
°C
* For proper operation.
ELECTRICAL CHARACTERISTICS
V
DD
= 15V, T
A
= 25°C, unless otherwise noted.
V
DD
Section
Symbol
V
DD-OP
V
DD-ON
V
DD-OFF
I
DD-ST
I
DD-OP
V
DD-CLAMP
t
D-VDDCLAMP
Parameter
Continuously Operating Voltage
Start Threshold Voltage
Minimum Operating Voltage
Start-up Current
Operating Supply Current
V
DD
Over-Voltage-Clamping Level
Test Condition
Min.
15
9
Typ.
16
10
14
4
Max.
24.7
17
11
30
5
Unit
V
V
V
µA
mA
V
V
DD
=V
DD-ON
–0.16V
V
DD
=15V, R
I
=26KΩ,
GATE=OPEN
28
50
29
100
200
V
DD
Over-Voltage-Clamping Debounce Time R
I
=26KΩ
µs
R
I
Section
Symbol
RI
NOR
RI
MAX
RI
MIN
Parameter
R
I
Operating Range
Maximum R
I
Value for Protection
Minimum R
I
Value for Protection
Test Condition
Min.
15.5
Typ.
230
10
Max.
36.0
Unit
KΩ
KΩ
KΩ
© System General Corp.
Version 1.3.1 (IAO33.0017.B6)
-4-
www.sg.com.tw • www.fairchildsemi.com
September 20, 2007
Product Specification
Highly Integrated Green-Mode PWM Controller
SG5841/J
Oscillator Section
Symbol
F
OSC
t
HOP
F
OSC-G
F
DV
F
DT
Parameter
Normal PWM Frequency
Hopping Period
Green-Mode Frequency
Frequency Variation vs. V
DD
Deviation
Center Frequency
Hopping Range
Test Condition
R
I
=26KΩ
R
I
=26KΩ (5841J only)
R
I
=26KΩ (5841J only)
R
I
=26KΩ
V
DD
=11.5V to 24.7V
Min.
62
±3.7
3.9
18
Typ.
65
±4.2
4.4
22
Max.
68
±4.7
4.9
25
5
5
Unit
KHz
ms
KHz
%
%
Frequency Variation vs. Temperature Deviation T
A
=-20 to +85°C
Feedback Input Section
Symbol
A
V
Z
FB
V
FB-OPEN
V
FB-OLP
t
D-OLP
V
FB-N
V
FB-G
Parameter
FB Input to Current Comparator Attenuation
Input Impedance
FB Output High Voltage
FB Open-Loop Trigger Level
Delay Time of FB pin Open-Loop Protection
Green-Mode Entry FB Voltage
Green-Mode Ending FB Voltage
Test Condition
Min.
1/3.75
4
Typ.
1/3.20
6
4.5
29
2.1
V
FB-N
-0.5
Max.
1/2.75
7
4.8
32
2.3
Unit
V/V
KΩ
V
V
ms
V
V
FB pin open
R
I
=26KΩ
R
I
=26KΩ
R
I
=26KΩ
5
4.2
26
1.9
Current-Sense Section
Symbol
Z
SENSE
V
STHFL
V
STHVA
t
PD
t
LEB
Parameter
Input Impedance
Current Limit Flatten Threshold Voltage
Current Limit Valley Threshold Voltage
Propagation Delay to GATE Output
Leading-Edge Blanking Time
Test Condition
Min.
0.85
Typ.
12
0.90
0.22
150
Max.
0.95
200
350
Unit
KΩ
V
V
ns
ns
V
STHFL
–V
STHVA
R
I
=26KΩ
R
I
=26KΩ
200
270
© System General Corp.
Version 1.3.1 (IAO33.0017.B6)
-5-
www.sg.com.tw • www.fairchildsemi.com
September 20, 2007
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