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Product Specification
Low Cost Green-Mode PWM Controller for Flyback Converters
SG6848
© System General Corp.
- 2 -
www.sg.com.tw
Version 1.2(IRO33.0010.B0)
May.06, 2003
MARKING DIAGRAMS
PIN CONFIGURATION
ORDERING INFORMATION
Part Number
PWM Frequency
Package
SG6848T 70kHz
6-Pin
SOT-26
SG6848D 70kHz
8-pin
DIP-8
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.
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
Input/Output
A resistor connected from the RI pin to ground will generate a constant current source for
the SG6848. 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 95kΩ resistor R
the SG6848. 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 95kΩ 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.
to the internal PWM comparator, so that the PWM comparator can control the duty cycle.
GND
8 / (1)
Supply
Ground.
M
: Mask Version
Y
: Year;
WW
: Work Week
1
2
3
3
4
5
6
SOT-26
GND
FB
RI
GATE
VDD
SENSE
1
M
A
YWW
XXXXXXX
: Wafer Lot
YY
: Year;
WW
: Week
V
: Assembly Location
8
1
SG6848D
XXXXXXXYYWWV
harman/kardon
Service manual DVD37EU
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