MC44603
Representative Block Diagram
R
R
ref
F Stby
R
F Stby
15 16
V
ref
Negative
Active
Clamp
R
S
Q
+
UVLO2
Demag
Detect
V
CC
V
aux
8
1
+
18.0 V
+
65 mV
3.7 V
V
Demag Out
Synchro
V
CC
Reference
Block
Sync
Input
14.5 V/7.5 V
V
To Power
Transforme
9
ref
+
V
I
I
F Stby
V
0.4 I
ref
ref
0.7 V
OSC prot
ref
1.0 V
R
S
V
C
Q
1.6 V
2
C
T
R
S
Q
10
+
V
OSC
Output
C
3.6 V
T
S
3
Q
R
4
V
Out
V
OVP
Thermal
Shutdown
2.0
Delay
µs
Gnd
0.4 I
I
ref
Discharge
V
ref
CC
V
V
V
V
V
ref
ref ref
0.6 I
ref
ref
0.25
V
ref
V
ref
0.8 I
ref
ref
I
F Stby
0.4 I
0.2 I
ref
0.4 I
ref
ref
11.6 k
5.0
µs
R
Pwr Stby
12
OVP
Delay
6
2.0 k
V
CC
1.0 mA
R
OVP
I
Discharge/2
+
Feed–
back
Current Mirror X2
+
2.5 V
2R
1.6 V
14
+
Error Amplifier
Current
Sense Input
2.5 V
Compen–
sation
7
13
1.0 V
UVLO1
5
V
Foldback
CC
2.4 V
5.0 mA
Input
+
9.0 V
11 SS/D
C
/VM
max
= Sink only
= Positive True Logic
R
SS
SS
This device contains 243 active transistors.
5
MOTOROLA ANALOG IC DEVICE DATA
ONSEMI [ ONSEMI ]
