Power integrations TOPSwitch-HX Series Manual page 19

Typical Uses of MULTI-FUNCTION (M) Pin (cont.)
+
R
DC
Input
Voltage
D
S
-
Figure 31. Line Sensing for Undervoltage, Overvoltage, Line Feed-Forward and
Latched Output Overvoltage Protection.
+
DC
Input
Voltage
D
6.2 V
S
-
Figure 33. Line Sensing for Undervoltage Only (Overvoltage Disabled).
+
DC
Input
Voltage
D
R
IL
S
-
Figure 35. Externally Set Current Limit (Not Normally Required – See M Pin
Operation Description).
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V = I × R + V (I
UV UV LS M M
V = I × R + V (I
OV OV LS M
For R = 4 MΩ
LS
V = 102.8 VDC
4 MΩ
UV
LS
V = 451 VDC
OV
Sense Output Voltage
DC @ 100 VDC = 76%
MAX
DC @ 375 VDC = 41%
MAX
M
CONTROL
C
PI-4729-120307
V = R × I + V (I
UV LS UV M
4 MΩ
For Values Shown
V = 103.8 VDC
UV
R
LS
40 kΩ
M
CONTROL
C
PI-4731-120307
For R = 12 kΩ
IL
I = 61%
LIMIT
For R = 19 kΩ
IL
I = 37%
LIMIT
See Figures 55b for other
resistor values (R ) to
IL
select different I
LIMIT
M
CONTROL
C
PI-4733-021308
+
= I )
UV
= I )
M OV
DC
Input
Voltage
-
Figure 32. Line Sensing for Undervoltage, Overvoltage, Line Feed-Forward and
Hysteretic Output Overvoltage Protection.
+
= I )
M UV
DC
Input
Voltage
-
Figure 34. Line Sensing for Overvoltage Only (Undervoltage Disabled). Maximum
Duty Cycle Reduced at Low Line and Further Reduction with
Increasing Line Voltage.
+
R
LS
DC
Input
Voltage
values.
R
IL
-
Figure 36. Current Limit Reduction with Line Voltage (Not Normally Required –
See M Pin Operation Description).
TOP252-262
V = I × R
UV UV
V = I × R
OV OV
For R = 4 MΩ
LS
V = 102.8 VDC
UV
V = 451 VDC
OV
Sense Output Voltage
R 4 MΩ
LS
R
OVP
VR
OVP
DC @ 100 VDC = 76%
D M
MAX
DC @ 375 VDC = 41%
MAX
CONTROL
C
S
V = I × R
OV OV
4 MΩ
For Values Shown
V = 457.2 VDC
OV
R
LS
55 kΩ
1N4148
D M
CONTROL
C
S
I =
100% @ 100 VDC
LIMIT
I = 53% @ 300 VDC
LIMIT
2.5 MΩ
D M
CONTROL
6 kΩ
C
S
+ V (I = I )
LS M M UV
+ V (I = I )
LS M M OV
R >3kΩ
OVP
PI-4730-120307
+ V (I = I )
LS M M OV
PI-4732-120307
PI-4734-092107
19
Rev. J 08/16