Product Specification
Low Cost Green-Mode PWM Controller for Flyback Converters
SG5701
System General Corp.
- 1 -
www.sg.com.tw
Version 1.0(IAO33.0025.B1)
Mar. 28, 2006
FEATURES
Green-Mode PWM
Supports the "Blue Angel" Standard
Low Start-up Current (10uA)
Low Operating Current (2mA)
Leading-Edge Blanking
Constant Output Power Limit
Universal Input
Built-in Synchronized Slope Compensation
Current Mode Operation
Cycle-by-cycle Current Limiting
Under Voltage Lockout (UVLO)
Programmable PWM Frequency
Gate Output Voltage Clamped at 17V
Low Cost
Few External Components Required
Small SOT-26 Package
APPLICATIONS
General-purpose switching mode power supplies and
flyback power converters, such as
Battery chargers for cellular phones, cordless phones,
PDAs, digital cameras, and power tools
Power adapters for ink jet printers, video game
consoles, and portable audio players
Open-frame SMPS for TV/DVD standby and other
auxiliary supplies, home appliances, and consumer
electronics
Replacements for linear transformers and RCC
SMPS
PC 5V standby power.
DESCRIPTION
This highly-integrated PWM controller provides
several special enhancements designed to meet the low
standby-power needs of low-power SMPS. To minimize
standby power consumption, the proprietary green-mode
function provides off-time modulation to linearly
decrease the switching frequency under light-load
conditions. This green-mode function enables the power
supply to easily meet even the strictest power
conservation requirements.
The BiCMOS fabrication process enables reducing
the start-up current to 10uA, and the operating current to
2mA. To further improve power conservation, a large
start-up resistance can be used. Built-in synchronized
slope compensation ensures the stability of peak current
mode control. Proprietary internal compensation provides
a constant output power limit over a universal AC input
range (90VAC to 264VAC). Pulse-by-pulse current
limiting ensures safe operation even during short-circuits.
To protect the external power MOSFET from being
damaged by supply over voltage, the SG5701's output
driver is clamped at 17V. SG5701 controllers can be used
to improve the performance and reduce the production
cost of power supplies. The SG5701 is the best choice for
replacing linear and RCC-mode power adapters. It is
available in 8-pin DIP and 6-pin SOT-26 packages.
TYPICAL APPLICATION
Product Specification
Low Cost Green-Mode PWM Controller for Flyback Converters
SG5701
System General Corp.
- 2 -
www.sg.com.tw
Version 1.0(IAO33.0025.B1)
Mar. 28, 2006
MARKING DIAGRAMS
PIN CONFIGURATION
ORDERING INFORMATION
Part Number
PWM Frequency
Package
SG5701TZ
70kHz
6-Pin SOT-26 (Lead Free)
SG5701DZ
70kHz
8-pin DIP-8 (Lead Free)
PIN DESCRIPTIONS
Pin No.
Name
DIP-8 / (SOT-26)
Type Function
GATE
1 / (6)
Driver Output The totem-pole output driver for driving the power MOSFET.
VDD
2 / (5)
Supply
Power supply.
NC 3
NC
pin.
SENSE
4 / (4)
Analog Input
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.
RI
5 / (3)
Analog
Input/Output
A resistor connected from the RI pin to ground will generate a constant current source for
the SG5701. This current is used to charge an internal capacitor, to determine the
switching frequency. Increasing the resistance will reduce the amplitude of the current
source and reduce the switching frequency. A 95k resistor R
i
results in a 50uA constant
current I
i
and a 70kHz switching frequency.
NC 6
NC
pin.
FB
7 / (2)
Analog Input
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.
GND
8 / (1)
Supply
Ground.
AAE:
SG5701
M:
Mask Version
W
: Week
: Lead Free
SOT-26
GND
FB
RI
GATE
VDD
SENSE
AAEMW
D
: D=DIP
P :
Z =Lead Free
Null=Regular Package
XXXXXXXX
: Wafer Lot
Y
: Year
WW
: Week
V
: Assembly Location
SG5701DP
XXXXXXXXYWWV
DIP-8
RI
NC
FB
GND
SENSE
NC
VDD
GATE
Product Specification
Low Cost Green-Mode PWM Controller for Flyback Converters
SG5701
System General Corp.
- 3 -
www.sg.com.tw
Version 1.0(IAO33.0025.B1)
Mar. 28, 2006
BLOCK DIAGRAM
Product Specification
Low Cost Green-Mode PWM Controller for Flyback Converters
SG5701
System General Corp.
- 4 -
www.sg.com.tw
Version 1.0(IAO33.0025.B1)
Mar. 28, 2006
ABSOLUTE MAXIMUM RATINGS
Symbol Parameter
Value
Unit
V
DD
DC Supply Voltage *
30
V
V
FB
Input Voltage to FB Pin
-0.3 to 6 V
V
V
SENCE
Input Voltage to Sense Pin
-0.3 to 6V
V
T
J
Operating Junction Temperature
150
SOT-26 247
P
D
Power Dissipation at T
A
=85
DIP-8 478
mW
SOT-26 263
R
JA
Thermal Resistance (Junction to Air)**
DIP-8 136
C/W
T
STG
Storage Temperature Range
-55 to +150
Pb free
260(+5/-0)
T
R
Peak Reflow Temperature
Pb 230(+5/-0)
C
ESD Capability, HBM Model
3.0
kV
* All voltage values, except differential voltages, are given with respect to the network ground terminal.
**Thermal JA test board size: SOT 18121.6mm/FR4; DIP 40351.6mm/FR4
Stress beyond those listed under " absolute maximum ratings" may cause permanent damage to the device.
RECOMMENDED OPERATING CONDITIONS
Symbol Parameter
Value
Unit
V
DD
DC Supply Voltage
24 V
T
A
Operating Ambient Temperature
-30 to +105
ELECTRICAL CHARACTERISTICS (T
A
= 25
C, V
DD
=15V)
VDD Section
Symbol Parameter
Test
Condition Min. Typ. Max.
Unit
V
OP
Continuously Operation Voltage
24
V
V
TH(ON)
Start Threshold Voltage
T
A
=25
C
15.3 16.3 17.3 V
V
DD(MIN)
Min. Operating Voltage
T
A
=25
C
10.9 11.7 12.5 V
I
DD-ST
Startup
Current
V
DD
= V
DD-ON
0.10V
10
30
uA
I
DD-OP
Operating Supply Current
V
DD
= 15V
2
5
mA
V
DD-CLAMP
VDD Clamp Voltage
24.5
25
26.5
V
Feedback Input Section
Symbol Parameter
Test
Condition Min. Typ. Max.
Unit
I
OZ
Zero Duty Cycle Input Current
1.3
2.0
mA
V
OP
Open Loop Voltage
4.2
V
Product Specification
Low Cost Green-Mode PWM Controller for Flyback Converters
SG5701
System General Corp.
- 5 -
www.sg.com.tw
Version 1.0(IAO33.0025.B1)
Mar. 28, 2006
Current Sense Section
Symbol Parameter
Test
Condition Min. Typ. Max.
Unit
Z
CS
Input
Impedance
10
k
T
PD
Delay
to
Output
60
100
nsec
V
TH,FLT
Current Limit Flatten Threshold Voltage
1.0
V
V
TH,VALLEY
Current Limit Valley Threshold Voltage
0.80
0.85
0.90
V
Oscillator Section
Symbol Parameter
Test
Condition Min. Typ. Max.
Unit
F
OSC
Frequency
R
I
=95k 65
70
75
kHz
F
OSC-GREEN
Green-Mode
Frequency
R
I
=95k
13
15
kHz
I
G
Green-Mode FB Input Current
1.05
mA
I
N
Green-Mode Start Threshold FB Input Current
I
n
= 0.3mA for a Maximum Duty Cycle
0.85
mA
S
G
Green-Mode Modulation Slope
R
I
=95k
300
Hz/uA
F
DY
Frequency Variation versus V
DD
Deviation
V
DD
=12 to 20V
0.02
2
%
F
DT
Frequency Variation versus Temp. Deviation
T
A
=-30 to 105 2 %
PWM Section
Symbol Parameter
Test
Condition Min. Typ. Max.
Unit
DC
(MAX)
Maximum Duty Cycle
70
75
80
%
DC
(MIN)
Minimum Duty Cycle
-
1
2
%
B
NK
Leading-Edge Blanking Time
200
nsec
Output Section
Symbol Parameter
Test
Condition Min. Typ. Max.
Unit
V
OL
Output
Voltage
Low
V
DD
=15V, I
o
=20mA
1.5 V
V
OH
Output
Voltage
High
V
DD
=15V, I
o
=20mA 8
V
T
R
Rising Time
V
DD
=15V, C
L
=1nF
250 350 nsec
T
F
Falling
Time
V
DD
=15V, C
L
=1nF
60 150 nsec
V
CLAMP
Output
Clamp
Voltage
V
DD
=20V 16
17
18
V
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