SG6858 Fairchild Semiconductor, SG6858 Datasheet - Page 2

• Manufacturer Part Number: SG6858
• Description: This highly integrated PWM controller provides several special enhancements designed to meet the low standby power needs of low-power SMPS
• Manufacturer: Fairchild Semiconductor

© 2008 Fairchild Semiconductor Corporation
SG6858 • Rev. 1.2.4
Typical Application
Block Diagram
VDD
L
AC Input
N
5(2)
SOT(DIP)
R
RI
C
FB
Filter
EMI
25V
3
2
FB
RI
16.5V/11.5V
OVP
SG6858
UVLO
GND
VDD
1
Internal
5
BIAS
SENSE
GATE
Rectifier
Bridge
Diode
+
6
4
Figure 1. Typical Application
C
Controller
Bulk
Figure 2. Block Diagram
Green
Mode
OSC
GND
1(8)
C
C
R
VDD
LF
Start
+
R
R
D
G
LF
2
VDD
R
S
R
SN
D
Q
SN
N
3(5)
A
C
R
RI
SN
SENSE
N
P
PC817
V limit ramp
2R
Compensation
N
3R
TL431
R
S
Slope
Driver
Soft
SN2
D
R
+
C
C
SN2
O1
+
C
R
O2
Blanking
F
Circuit
5V
V
R
DD
d
C
F
ZD
O
6(1)
4(4)
2(7)
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R
R
1
2
GATE
SENSE
FB
V
V
O
O
+
-