UC384XA - UC284XA
Figure 21. Isolated MOSFET Drive and Current Transformer Sensing.
VCC
Vin
7
+
5.0Vref
-
+
-
S
Q
R
-
+
COMP/LATCH
6
3
C
D95IN349
Figure 22. Latched Shutdown.
ISOLATION
BOUNDARY
R
RS
VGS Waveforms
Q1
+
+
0
0
-
50% DC
-
25% DC
( ) Ipk =
V(pin 1) -1.4
3RS
NS
NP
NS
NP
2N
3905
4
OSC
8
R
BIAS
R
+
+
-
2
EA
1mA
2R
R
1
5
2N
3903
D95IN350
SCR must be selected for a holding current of less than 0.5mA at TA(min).
The simple two transistor circuit can be used in place of the SCR as shown. All resistors are 10K.
9/16