DPA422 Datasheet, PDF (12/34 Pages) Power Integrations, Inc. – Highly Integrated DC-DC Converter ICs for Power over Ethernet & Telecom Applications

DPA422-426
Typical Uses of LINE-SENSE (L) and EXTERNAL CURRENT LIMIT (X) Pins (cont.)
+
DC
Input
Voltage
For R_IL = 12 k
I_LIMIT = 64%
For R_IL = 25 k
I_LIMIT = 34%
See Figure 32 for other
D
resistor values (R_IL)
CONTROL
C
S
X
R_IL
-
Figure 15. Externally Set Current Limit.
PI-2836-050602
+
R_LS 363 k
I_LIMIT = 100% @ 36 VDC
I_LIMIT = _{64% @ 72 VDC}
DC
Input
Voltage
-
D
CONTROL
C
S
X
R_IL
4.2 k
Figure 16. Current Limit Reduction with Line Voltage.
PI-2854-050602
+
Q_R can be an optocoupler
output or can be replaced by
a manual switch.
DC
Input
Voltage
D
CONTROL
C
S
X
-
Q_R
47 K
Figure 17. Active-on (Fail Safe) Remote ON/OFF.
ON/OFF
PI-2625-040501
+
ON/OFF
DC
Input
Voltage
Q_R
47 k
R_MC
37.4 k
D
L
CONTROL
C
Q_R can be an
optocoupler output or
can be replaced
by a manual switch.
-
S
PI-2855-050602
Figure 18. Active-off Remote ON/OFF. Maximum Duty Cycle Will Be Reduced.
DC
Input
Voltage
D
CONTROL
C
S
X
ON/OFF
Figure 19. Active-on Remote ON/OFF with Externally Set Current Limit.
+
ON/OFF
DC
Input
Voltage
Q_R
47 k
R_MC
37.4 k
D
L
CONTROL
C
Q_R can be an
optocoupler output
or can be replaced
by a manual switch.
For R_IL = 12 k
I_LIMIT = 64%
For R_IL = 25 k
I_LIMIT = 34%
S
X
R_IL
-
PI-2857-050602
Figure 20. Active-off Remote ON/OFF with Externally Set Current Limit.
12
Rev. T 12/12
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