FSDH321, FSDL321
2
Internal Block Diagram
Figure 2. Functional Block Diagram of FSDx321
8V/12V
2
6,7,8
1
3
Vref
Internal
Bias
S
Q
Q
R
OSC
Vcc
Vcc
I
DELAY
I
FB
V
SD
TSD
Vovp
Vcc
Vocp
S
Q
Q
R
R
2.5R
Vcc good
Vcc
Drain
Vfb
GND
AOCP
Gate
driver
5
Vstr
I
CH
Vcc good
V
BURL
/V
BURH
LEB
PWM
+
-
4
Ipk
Freq.
Modulation
V
BURH
Vcc
I
BUR(pk)
Burst
Normal
Soft
Start