Vicor Corp.
Tel: 800-735-6200, 978-470-2900 Fax: 978-475-6715
375V Maxi Family
Rev. 6.1
Page 4 of 8
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CONTROLFUNCTIONS - PC PIN
Module Enable/Disable
The module may be disabled by pulling PC below 2.3V with
respect to the –Input. This may be done with an open collector
transistor, relay, or optocoupler. Multiple converters may be
disabled with a single transistor or relay either directly or via
“OR’ing” diodes. See Figure 1.
Module Alarm
The module contains “watchdog” circuitry which monitors
input voltage, operating temperature and internal operating
parameters. In the event that any of these parameters are
outside of their allowable operating range, the module will shut
down and PC will go low. PC will periodically go high and the
module will check to see if the fault (as an example,
overtemperature) has cleared. If the fault has not been cleared,
PC will go low again and the cycle will restart. The SC pin will
go low in the event of a fault and return to its normal state after
the fault has been cleared. See Figures 2 and 4.
+In
PC
PR
–
In
Disable
Disable = PC <2.3V
Figure 1
—Module enable/disable.
Figure 3
—LED on-state indicator.
+In
PC
PR
–
In
4k
"Module
Enabled"
+In
PC
PR
–
In
Optocoupler
4k
Alarm
1.00V
+Out
+S
SC
–
S
–
Out
+Out
+S
SC
–
S
–
Out
+In
PC
PR
–
In
Input Undervoltage
Overtemperature
Module Faults
2-20ms typ.
f (VIN)
Auto
Restart
5.7Vdc
(0-3mA)
50
SW2
SW3
1.23
Vdc
6K
1K
SW1
SW1, 2, & 3
shown in
"Fault" position
Figure 2
—PC/SC module alarm logic.
Figure 5
—Isolated on-state indicator.
2-20ms typ.
Fault
SC
PC
1.23V
5.7V
40
μ
s typ.
Figure 4
—PC/SC module alarm timing.
Figure 6
—Secondary side on-state indicator.
Primary Auxiliary Supply
At 5.7V, PC can source up to 1.5mA. In the example shown in
Figure 3, PC powers a module enabled LED.