Typical Circuit
VO
AC
IN
Vstr
Drain
Sync
PWM
GND
Vfb Vcc
FSQ0365RN Rev.00
Figure 1. Typical Flyback Application
Internal Block Diagram
Vfb
3
Sync
4
0.7V/0.2V
+
0.35/0.55
VCC
Vref
VBurst
-
Idelay
IFB
3R
R
Soft-
Start
+
-
PWM
Vstr
5
Vcc Drain
2 678
OSC
Vref
VCC good
+
-
8V/12V
LEB
200ns
SQ
RQ
Gate
driver
6V
VSD
Sync
6V
Vovp
TSD
2.5μs time
delay
VCC good
SQ
RQ
AOCP
Figure 2. Functional Block Diagram
VOCP
(1.1V)
1
GND
FSQ0365RN Rev.00
© 2006 Fairchild Semiconductor Corporation
FSQ0365, FSQ0265, FSQ0165, FSQ321, FSQ311 Rev. 1.0.4
3
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