Datasheet

4
Supertex inc.
www.supertex.com
Doc.# DSFP-LR8
B080113
LR8
Typical Application Circuits
Figure 2: SMPS Start-Up Circuit
Figure 3: High Voltage Adjustable Constant Current Source
Figure 1: High Input Voltage, 5.0V Output Linear Regulator
+
V
OUT
1
-
V
CC
V
AUXILIARY
V
IN
= (V
OUT
+ 12V) to 450V
FB
PWM IC
+
V
OUT
1
-
LR8
VOUT
ADJ
VIN
V
IN
=
17 to 450V
*
R
1
6.04kΩ
1%
C
2
1.0µF
C
1
R
LOAD
≤16.5kΩ
V
OUT
= 5.0V
R
2
18.2kΩ
1%
* Required for conditions where V
IN
is less than V
OUT
V
OUT
= 1.20V 1+
R
2
+ I
ADJ
R
1
LR8
VOUT
ADJ
VIN
LR8
V
IN
=
(V
OUT
+ 12V) to 450V
R
Load
I
OUT
=
1.20V
R
+
-
1.0µF
VOUT
ADJ
VIN