Datasheet
TOP242-250
18
I
4/03
General Information & Table of Contents
Product Selector Guide 1
Data Sheets 2
Application Notes 3
Design Ideas 4
Design Tools 5
Quality and Reliability 6
Package Information 7
DPA-Switch
 DC-DC Seminar 8
LinkSwitch 
&
 TinySwitch-II
 AC-DC Seminar 9
TOPSwitch-GX
 AC-DC Seminar 10
Sales Representatives and Distributors 11
Typical Uses of LINE-SENSE (L) and EXTERNAL CURRENT LIMIT (X) Pins (cont.)
Figure 28. Line-Sensing and Externally Set Current Limit.
PI-2640-040501
DC
Input
Voltage
+
-
D
S
C
CONTROL
L
ON/OFF
47 kΩ
Q
R
 can be an optocoupler 
output or can be replaced by 
a manual switch.
300 kΩ
Q
R
Figure 29. Active-on Remote ON/OFF.
X
PI-2629-040501
DC
Input
Voltage
+
-
D
S
C
CONTROL
L
R
IL
R
LS
12 kΩ
2 MΩ
 V
UV
 = I
UV
 x R
LS
 V
OV 
=
I
OV 
x
R
LS
For R
LS
 =
2
MΩ
DC
MAX
@100 VDC = 78%
DC
MAX
@375 VDC = 38%
 For R
IL
 = 12 kΩ
 I
LIMIT
 = 69%
 See fig. 55 for other
 resistor values (R
IL
)
 to select different I
LIMIT
 values
 V
UV
 = 100 VDC
 V
OV
 = 450 VDC 










